< draft-reddy-dots-transport-05.txt   draft-reddy-dots-transport-06.txt >
DOTS T. Reddy DOTS T. Reddy
Internet-Draft D. Wing Internet-Draft D. Wing
Intended status: Standards Track P. Patil Intended status: Standards Track P. Patil
Expires: January 7, 2017 M. Geller Expires: February 9, 2017 M. Geller
Cisco Cisco
M. Boucadair M. Boucadair
Orange Orange
R. Moskowitz August 8, 2016
HTT Consulting
July 6, 2016
Co-operative DDoS Mitigation Co-operative DDoS Mitigation
draft-reddy-dots-transport-05 draft-reddy-dots-transport-06
Abstract Abstract
This document specifies a mechanism that a DOTS client can use to This document specifies a mechanism that a DOTS client can use to
signal that a network is under a Distributed Denial-of-Service (DDoS) signal that a network is under a Distributed Denial-of-Service (DDoS)
attack to an upstream DOTS server so that appropriate mitigation attack to an upstream DOTS server so that appropriate mitigation
actions are undertaken (including, blackhole, drop, rate-limit, or actions are undertaken (including, blackhole, drop, rate-limit, or
add to watch list) on the suspect traffic. The document specifies add to watch list) on the suspect traffic. The document specifies
both DOTS signal and data channels. Happy Eyeballs considerations both DOTS signal and data channels. Happy Eyeballs considerations
for the DOTS signal channel are also elaborated. for the DOTS signal channel are also elaborated.
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 7, 2017. This Internet-Draft will expire on February 9, 2017.
Copyright Notice Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
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publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
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the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Notational Conventions . . . . . . . . . . . . . . . . . . . 3 2. Notational Conventions and Terminology . . . . . . . . . . . 3
3. Solution Overview . . . . . . . . . . . . . . . . . . . . . . 3 3. Solution Overview . . . . . . . . . . . . . . . . . . . . . . 4
4. Happy Eyeballs for DOTS Signal Channel . . . . . . . . . . . 6 4. Happy Eyeballs for DOTS Signal Channel . . . . . . . . . . . 5
5. DOTS Signal Channel . . . . . . . . . . . . . . . . . . . . . 7 5. DOTS Signal Channel . . . . . . . . . . . . . . . . . . . . . 6
5.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 7 5.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 6
5.2. Mitigation Service Requests . . . . . . . . . . . . . . . 8 5.2. Mitigation Service Requests . . . . . . . . . . . . . . . 7
5.2.1. Convey DOTS Signals . . . . . . . . . . . . . . . . . 9 5.2.1. Convey DOTS Signals . . . . . . . . . . . . . . . . . 8
5.2.2. Withdraw a DOTS Signal . . . . . . . . . . . . . . . 11 5.2.2. Withdraw a DOTS Signal . . . . . . . . . . . . . . . 11
5.2.3. Retrieving a DOTS Signal . . . . . . . . . . . . . . 12 5.2.3. Retrieving a DOTS Signal . . . . . . . . . . . . . . 12
5.2.4. Efficacy Update from DOTS Client . . . . . . . . . . 15 5.2.4. Efficacy Update from DOTS Client . . . . . . . . . . 16
6. DOTS Data Channel . . . . . . . . . . . . . . . . . . . . . . 15 6. DOTS Data Channel . . . . . . . . . . . . . . . . . . . . . . 16
6.1. Filtering Rules . . . . . . . . . . . . . . . . . . . . . 16 6.1. Filtering Rules . . . . . . . . . . . . . . . . . . . . . 17
6.1.1. Install Filtering Rules . . . . . . . . . . . . . . . 16 6.1.1. Install Filtering Rules . . . . . . . . . . . . . . . 18
6.1.2. Remove Filtering Rules . . . . . . . . . . . . . . . 18 6.1.2. Remove Filtering Rules . . . . . . . . . . . . . . . 20
6.1.3. Retrieving Installed Filtering Rules . . . . . . . . 18 6.1.3. Retrieving Installed Filtering Rules . . . . . . . . 20
7. (D)TLS Protocol Profile and Performance considerations . . . 19 7. (D)TLS Protocol Profile and Performance considerations . . . 22
8. Mutual Authentication of DOTS Agents & Authorization of DOTS 8. Mutual Authentication of DOTS Agents & Authorization of DOTS
Clients . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Clients . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25
10. Security Considerations . . . . . . . . . . . . . . . . . . . 22 10. Security Considerations . . . . . . . . . . . . . . . . . . . 25
11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 22 11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 25
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 22 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 26
12.1. Normative References . . . . . . . . . . . . . . . . . . 22 13. References . . . . . . . . . . . . . . . . . . . . . . . . . 26
12.2. Informative References . . . . . . . . . . . . . . . . . 23 13.1. Normative References . . . . . . . . . . . . . . . . . . 26
Appendix A. BGP . . . . . . . . . . . . . . . . . . . . . . . . 25 13.2. Informative References . . . . . . . . . . . . . . . . . 27
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 25 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 29
1. Introduction 1. Introduction
A distributed denial-of-service (DDoS) attack is an attempt to make A distributed denial-of-service (DDoS) attack is an attempt to make
machines or network resources unavailable to their intended users. machines or network resources unavailable to their intended users.
In most cases, sufficient scale can be achieved by compromising In most cases, sufficient scale can be achieved by compromising
enough end-hosts and using those infected hosts to perpetrate and enough end-hosts and using those infected hosts to perpetrate and
amplify the attack. The victim in this attack can be an application amplify the attack. The victim in this attack can be an application
server, a client, a router, a firewall, or an entire network, etc. server, a client, a router, a firewall, or an entire network, etc.
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various vendors that are deployed within the same network, some of various vendors that are deployed within the same network, some of
them are responsible for monitoring and detecting attacks while them are responsible for monitoring and detecting attacks while
others are responsible for enforcing policies on appropriate network others are responsible for enforcing policies on appropriate network
elements. This cooperations contributes to a ensure a highly elements. This cooperations contributes to a ensure a highly
automated network that is also robust, reliable and secure. The automated network that is also robust, reliable and secure. The
advantage of this mechanism is that the DOTS server can provide advantage of this mechanism is that the DOTS server can provide
protection to the DOTS client from bandwidth-saturating DDoS traffic. protection to the DOTS client from bandwidth-saturating DDoS traffic.
How a Mitigator determines which network elements should be modified How a Mitigator determines which network elements should be modified
to install appropriate filtering rules is out of scope. A variety of to install appropriate filtering rules is out of scope. A variety of
mechanisms and protocols (including NETCONF) may be considered to mechanisms and protocols (including NETCONF [RFC6241]) may be
exchange information through a communication interface between the considered to exchange information through a communication interface
server and these underlying elements; the selection of appropriate between the server and these underlying elements; the selection of
mechanisms and protocols to be invoked for that interfaces is appropriate mechanisms and protocols to be invoked for that
deployment-specific. interfaces is deployment-specific.
Terminology and protocol requirements for co-operative DDoS Terminology and protocol requirements for co-operative DDoS
mitigation are obtained from [I-D.ietf-dots-requirements]. mitigation are obtained from DOTS requirements
[I-D.ietf-dots-requirements]. This document satisfies all the use
cases discussed in [I-D.ietf-dots-use-cases] except the Third-party
DOTS notifications use case in Section 3.2.3 of
[I-D.ietf-dots-use-cases] which is an optional feature and not a core
use case. Third-party DOTS notifications are not part of the DOTS
requirements document and the DOTS architecture
[I-D.ietf-dots-architecture] does not assess whether that use case
may have an impact on the architecture itself and/or trust model.
2. Notational Conventions 2. Notational Conventions and Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
(D)TLS: For brevity this term is used for statements that apply to
both Transport Layer Security [RFC5246] and Datagram Transport Layer
Security [RFC6347]. Specific terms will be used for any statement
that applies to either protocol alone.
3. Solution Overview 3. Solution Overview
Network applications have finite resources like CPU cycles, number of Network applications have finite resources like CPU cycles, number of
processes or threads they can create and use, maximum number of processes or threads they can create and use, maximum number of
simultaneous connections it can handle, limited resources of the simultaneous connections it can handle, limited resources of the
control plane, etc. When processing network traffic, such an control plane, etc. When processing network traffic, such an
application uses these resources to offer its intended task in the application uses these resources to offer its intended task in the
most efficient fashion. However, an attacker may be able to prevent most efficient fashion. However, an attacker may be able to prevent
the application from performing its intended task by causing the the application from performing its intended task by causing the
application to exhaust the finite supply of a specific resource. application to exhaust the finite supply of a specific resource.
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TCP DDoS SYN-flood, for example, is a memory-exhaustion attack on the TCP DDoS SYN-flood, for example, is a memory-exhaustion attack on the
victim and ACK-flood is a CPU exhaustion attack on the victim victim and ACK-flood is a CPU exhaustion attack on the victim
([RFC4987]). Attacks on the link are carried out by sending enough ([RFC4987]). Attacks on the link are carried out by sending enough
traffic such that the link becomes excessively congested, and traffic such that the link becomes excessively congested, and
legitimate traffic suffers high packet loss. Stateful firewalls can legitimate traffic suffers high packet loss. Stateful firewalls can
also be attacked by sending traffic that causes the firewall to hold also be attacked by sending traffic that causes the firewall to hold
excessive state and the firewall runs out of memory, and can no excessive state and the firewall runs out of memory, and can no
longer instantiate the state required to pass legitimate flows. longer instantiate the state required to pass legitimate flows.
Other possible DDoS attacks are discussed in [RFC4732]. Other possible DDoS attacks are discussed in [RFC4732].
In each of the cases described above, some of the possible In each of the cases described above, the possible arrangements
arrangements to mitigate the attack are: between the DOTS client and DOTS server to mitigate the attack are
discussed in [I-D.ietf-dots-use-cases]. An example of network
o If a DOTS client determines it is under an attack, the DOTS client diagram showing a deployment of these elements is shown in Figure 1.
can notify the DOTS server using the DOTS signal that it is under Architectural relationship between DOTS agents is explained in
a potential attack and request that the DOTS server take [I-D.ietf-dots-architecture]. In this example, the DOTS server is
precautionary measures to mitigate the attack. The DOTS server operating on the access network.
can enable mitigation on behalf of the DOTS client by
communicating the DOTS client's request to the mitigator and
relaying any mitigator feedback to the requesting DOTS client.
o If a DOTS client determines it is under an attack, the DOTS client
can notify its servicing router (DOTS gateway) using the DOTS
signal that it is under a potential attack and request that the
DOTS gateway take precautionary measures to mitigate the attack.
The DOTS gateway propagates the DOTS signal to a DOTS server.
The DOTS server can enable mitigation on behalf of the DOTS
gateway by communicating the DOTS gateway's request to the
mitigator and relaying any mitigator feedback to the DOTS gateway
which in turn propagates the feedback to the requesting DOTS
client.
The DOTS client must authenticate itself to the DOTS gateway,
which in turn authenticates itself to a DOTS server, creating a
two-link chain of transitive authentication between the DOTS
client and the DOTS server (Section 8).
o If a network resource detects a potential DDoS attack from a set
of IP addresses, the network resource (DOTS client) informs its
servicing router (DOTS gateway) of all suspect IP addresses that
need to be blocked or black-listed for further investigation.
The DOTS client could also specify a list of protocols and ports
in the black-list rule. That DOTS gateway in-turn propagates the
black-listed IP addresses to the DOTS server and the DOTS server
blocks traffic from these IP addresses to the DOTS client thus
reducing the effectiveness of the attack.
The DOTS client periodically queries the DOTS server to check the
counters mitigating the attack. If the DOTS client receives a
response that the counters have not incremented then it can
instruct the black-list rules to be removed. If a blacklisted
IPv4 address is shared by multiple subscribers, then the side
effect of applying the black-list rule will be that traffic from
non-attackers will also be blocked by the access network
[RFC6269].
An example of network diagram showing a deployment of these elements
is shown in Figure 1. In this example, the DOTS server operating on
the access network.
Network Network
Resource CPE router Access network __________ Resource CPE router Access network __________
+-----------+ +--------------+ +-------------+ / \ +-----------+ +--------------+ +-------------+ / \
| |____| |_______| |___ | Internet | | |____| |_______| |___ | Internet |
|DOTS client| | DOTS gateway | | DOTS server | | | |DOTS client| | DOTS gateway | | DOTS server | | |
| | | | | | | | | | | | | | | |
+-----------+ +--------------+ +-------------+ \__________/ +-----------+ +--------------+ +-------------+ \__________/
Figure 1 Figure 1
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The DOTS server may (not) be co-located with the DOTS mitigator. In The DOTS server may (not) be co-located with the DOTS mitigator. In
typical deployments, the DOTS server belongs to the same typical deployments, the DOTS server belongs to the same
administrative domain as the mitigator. administrative domain as the mitigator.
The DOTS client can communicate directly with the DOTS server or The DOTS client can communicate directly with the DOTS server or
indirectly with the DOTS server via a DOTS gateway. indirectly with the DOTS server via a DOTS gateway.
4. Happy Eyeballs for DOTS Signal Channel 4. Happy Eyeballs for DOTS Signal Channel
DOTS signaling can happen with DTLS over UDP and TLS over TCP. A DOTS signaling can happen with DTLS [RFC6347] over UDP and TLS
DOTS client can use DNS to determine the IP address(es) of a DOTS [RFC5246] over TCP. A DOTS client can use DNS to determine the IP
server or a DOTS client may be provided with the list of DOTS server address(es) of a DOTS server or a DOTS client may be provided with
IP addresses. The DOTS client must know a DOTS server's domain name; the list of DOTS server IP addresses. The DOTS client MUST know a
hard-coding the domain name of the DOTS server into software is NOT DOTS server's domain name; hard-coding the domain name of the DOTS
RECOMMENDED in case the domain name is not valid or needs to change server into software is NOT RECOMMENDED in case the domain name is
for legal or other reasons. The DOTS client performs A and/or AAAA not valid or needs to change for legal or other reasons. The DOTS
record lookup of the domain name and the result will be a list of IP client performs A and/or AAAA record lookup of the domain name and
addresses, each of which can be used to contact the DOTS server using the result will be a list of IP addresses, each of which can be used
UDP and TCP. to contact the DOTS server using UDP and TCP.
If an IPv4 path to reach a DOTS server is found, but the DOTS If an IPv4 path to reach a DOTS server is found, but the DOTS
server's IPv6 path is not working, a dual-stack DOTS client can server's IPv6 path is not working, a dual-stack DOTS client can
experience a significant connection delay compared to an IPv4-only experience a significant connection delay compared to an IPv4-only
DOTS client. The other problem is that if a middlebox between the DOTS client. The other problem is that if a middlebox between the
DOTS client and DOTS server is configured to block UDP, the DOTS DOTS client and DOTS server is configured to block UDP, the DOTS
client will fail to establish a DTLS session [RFC6347] with the DOTS client will fail to establish a DTLS session with the DOTS server and
server and will, then, have to fall back to TLS over TCP [RFC5246] will, then, have to fall back to TLS over TCP incurring significant
incurring significant connection delays. connection delays. [I-D.ietf-dots-requirements] discusses that DOTS
[I-D.ietf-dots-requirements] discusses that DOTS client and server client and server will have to support both connectionless and
will have to support both connectionless and connection-oriented connection-oriented protocols.
protocols.
To overcome these connection setup problems, the DOTS client can try To overcome these connection setup problems, the DOTS client can try
connecting to the DOTS server using both IPv6 and IPv4, and try both connecting to the DOTS server using both IPv6 and IPv4, and try both
DTLS over UDP and TLS over TCP in a fashion similar to the Happy DTLS over UDP and TLS over TCP in a fashion similar to the Happy
Eyeballs mechanism [RFC6555]. These connection attempts are Eyeballs mechanism [RFC6555]. These connection attempts are
performed by the DOTS client when its initializes, and the client performed by the DOTS client when its initializes, and the client
uses that information for its subsequent alert to the DOTS server. uses that information for its subsequent alert to the DOTS server.
In order of preference (most preferred first), it is UDP over IPv6, In order of preference (most preferred first), it is UDP over IPv6,
UDP over IPv4, TCP over IPv6, and finally TCP over IPv4, which UDP over IPv4, TCP over IPv6, and finally TCP over IPv4, which
adheres to address preference order [RFC6724] and the DOTS preference adheres to address preference order [RFC6724] and the DOTS preference
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| TLS | DTLS | | TLS | DTLS |
+--------------+ +--------------+
| TCP | UDP | | TCP | UDP |
+--------------+ +--------------+
| IP | | IP |
+--------------+ +--------------+
Figure 4: Abstract Layering of DOTS signal channel over CoAP over Figure 4: Abstract Layering of DOTS signal channel over CoAP over
(D)TLS (D)TLS
JSON [RFC7159] payloads is used to convey signal channel specific JSON [RFC7159] payloads are used to convey signal channel specific
payload messages that convey request parameters and response payload messages that convey request parameters and response
information such as errors. information such as errors.
TBD: Do we want to use CBOR [RFC7049] instead of JSON? TBD: Do we want to use CBOR [RFC7049] instead of JSON?
5.2. Mitigation Service Requests 5.2. Mitigation Service Requests
The following APIs define the means to convey a DOTS signal from a The following APIs define the means to convey a DOTS signal from a
DOTS client to a DOTS server: DOTS client to a DOTS server:
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PUT requests: are used by the DOTS client to convey mitigation PUT requests: are used by the DOTS client to convey mitigation
efficacy updates to the DOTS server (Section 5.2.4). efficacy updates to the DOTS server (Section 5.2.4).
Reliability is provided to the POST, DELETE, GET, and PUT requests by Reliability is provided to the POST, DELETE, GET, and PUT requests by
marking them as Confirmable (CON) messages. As explained in marking them as Confirmable (CON) messages. As explained in
Section 2.1 of [RFC7252], a Confirmable message is retransmitted Section 2.1 of [RFC7252], a Confirmable message is retransmitted
using a default timeout and exponential back-off between using a default timeout and exponential back-off between
retransmissions, until the DOTS server sends an Acknowledgement retransmissions, until the DOTS server sends an Acknowledgement
message (ACK) with the same Message ID conveyed from the DOTS client. message (ACK) with the same Message ID conveyed from the DOTS client.
Message transmission parameters are defined in Section 4.8 of
[RFC7252]. Reliablity is provided to the responses by marking them
as Confirmable (CON) messages. The DOTS server can either piggback
the response in the acknowledgement message or if the DOTS server is
not able to respond immediately to a request carried in a Confirmable
message, it simply responds with an Empty Acknowledgement message so
that the DOTS client can stop retransmitting the request. Empty
Acknowledgement message is explained in Section 2.2 of [RFC7252].
When the response is ready, the server sends it in a new Confirmable
message which then in turn needs to be acknowledged by the DOTS
client (see Sections 5.2.1 and Sections 5.2.2 in [RFC7252]).
TBD: Do we want any of the above requests to be Non-confirmable ? Implementation Note: A DOTS client that receives a response in a CON
message may want to clean up the message state right after sending
the ACK. If that ACK is lost and the DOTS server retransmits the
CON, the DOTS client may no longer have any state to which to
correlate this response, making the retransmission an unexpected
message; the DOTS client will send a Reset message so it does not
receive any more retransmissions. This behavior is normal and not an
indication of an error (see Section 5.3.2 in [RFC7252] for more
details).
5.2.1. Convey DOTS Signals 5.2.1. Convey DOTS Signals
A POST request is used to convey a DOTS signal to the DOTS server When suffering an attack and desiring DoS/DDoS mitigation, a DOTS
(Figure 5). signal is sent by the DOTS client to the DOTS server. A POST request
is used to convey a DOTS signal to the DOTS server (Figure 5). The
DOTS server can enable mitigation on behalf of the DOTS client by
communicating the DOTS client's request to the mitigator and relaying
any mitigator feedback to the requesting DOTS client.
POST {scheme}://{host}:{port}/.well-known/{version}/{URI suffix for DOTS signal} Header: POST (Code=0.02)
Accept: application/json Uri-Host: "host"
Content-Format: application/json Uri-Path: ".well-known"
{ Uri-Path: "DOTS-signal"
"policy-id": "number", Uri-Path: "version"
"target-ip": "string", Content-Type: "application/json"
"target-port": "string", {
"target-protocol": "string", "policy-id": "integer",
"lifetime": "number" "target-ip": "string",
} "target-port": "string",
"target-protocol": "string",
"lifetime": "number"
}
Figure 5: POST to convey DOTS signals Figure 5: POST to convey DOTS signals
The header fields are described below. The header fields are described below.
policy-id: Identifier of the policy represented using a number. policy-id: Identifier of the policy represented using a integer.
This identifier MUST be unique for each policy bound to the DOTS This identifier MUST be unique for each policy bound to the DOTS
client, i.e. ,the policy-id needs to be unique relative to the client, i.e. ,the policy-id needs to be unique relative to the
active policies with the DOTS server. This identifier must be active policies with the DOTS server. This identifier must be
generated by the DOTS client. This document does not make any generated by the DOTS client. This document does not make any
assumption about how this identifier is generated. This is a assumption about how this identifier is generated. This is a
mandatory attribute. mandatory attribute.
target-ip: A list of IP addresses or prefixes under attack. This is target-ip: A list of IP addresses or prefixes under attack. IP
an optional attribute. addresses and prefixes are separated by commas. Prefixes are
represented using CIDR notation [RFC4632]. This is an optional
attribute.
target-port: A list of ports under attack. This is an optional target-port: A list of ports under attack. Ports are seperated by
commas and port number range (using "-"). For TCP, UDP, SCTP, or
DCCP: the range of ports (e.g., 1024-65535). This is an optional
attribute. attribute.
target-protocol: A list of protocols under attack. Valid protocol target-protocol: A list of protocols under attack. Valid protocol
values include tcp, udp, sctp, and dccp. This is an optional values include tcp, udp, sctp, and dccp. Protocol values are
attribute. seperated by commas. This is an optional attribute.
lifetime: Lifetime of the mitigation request policy in seconds. lifetime: Lifetime of the mitigation request policy in seconds.
Upon the expiry of this lifetime, and if the request is not Upon the expiry of this lifetime, and if the request is not
refreshed, the mitigation request is removed. The request can be refreshed, the mitigation request is removed. The request can be
refreshed by sending the same request again. The default lifetime refreshed by sending the same request again. The default lifetime
of the policy is 60 minutes -- this value was chosen to be long of the policy is 60 minutes -- this value was chosen to be long
enough so that refreshing is not typically a burden on the DOTS enough so that refreshing is not typically a burden on the DOTS
client, while expiring the policy where the client has client, while expiring the policy where the client has
unexpectedly quit in a timely manner. A lifetime of zero unexpectedly quit in a timely manner. A lifetime of zero
indicates indefinite lifetime for the mitigation request. The indicates indefinite lifetime for the mitigation request. The
server MUST always indicate the actual lifetime in the response. server MUST always indicate the actual lifetime in the response.
This is an optional attribute in the request. This is an optional attribute in the request.
The relative order of two rules is determined by comparing their The relative order of two rules is determined by comparing their
respective policy identifiers. The rule with lower numeric policy respective policy identifiers. The rule with lower numeric policy
identifier value has higher precedence (and thus will match before) identifier value has higher precedence (and thus will match before)
than the rule with higher numeric policy identifier value. than the rule with higher numeric policy identifier value.
If the DOTS server is not able to respond immediately to a POST
request carried in a Confirmable message, it simply responds with an
Empty Acknowledgement message so that the DOTS client can stop
retransmitting the request. When the response is ready, the server
sends it in a new Confirmable message which then in turn needs to be
acknowledged by the DOTS client (see Sections 5.2.1 and Sections
5.2.2 in [RFC7252]).
To avoid DOTS signal message fragmentation and the consequently To avoid DOTS signal message fragmentation and the consequently
decreased probability of message delivery, DOTS agents MUST ensure decreased probability of message delivery, DOTS agents MUST ensure
that the DTLS record MUST fit within a single datagram. If the Path that the DTLS record MUST fit within a single datagram. If the Path
MTU is not known to the DOTS server, an IP MTU of 1280 bytes SHOULD MTU is not known to the DOTS server, an IP MTU of 1280 bytes SHOULD
be assumed. The length of the URL MUST NOT exceed 256 bytes. If UDP be assumed. The length of the URL MUST NOT exceed 256 bytes. If UDP
is used to convey the DOTS signal and the request size exceeds the is used to convey the DOTS signal and the request size exceeds the
Path MTU then the DOTS client MUST split the DOTS signal into Path MTU then the DOTS client MUST split the DOTS signal into
separate messages, for example the list of addresses in the 'target- separate messages, for example the list of addresses in the 'target-
ip' field could be split into multiple lists and each list conveyed ip' field could be split into multiple lists and each list conveyed
in a new POST request. in a new POST request.
skipping to change at page 11, line 5 skipping to change at page 11, line 5
consideration and path MTU is unknown, implementations may want to consideration and path MTU is unknown, implementations may want to
limit themselves to more conservative IPv4 datagram sizes such as 576 limit themselves to more conservative IPv4 datagram sizes such as 576
bytes, as per [RFC0791] IP packets up to 576 bytes should never need bytes, as per [RFC0791] IP packets up to 576 bytes should never need
to be fragmented, thus sending a maximum of 500 bytes of DOTS signal to be fragmented, thus sending a maximum of 500 bytes of DOTS signal
over a UDP datagram will generally avoid IP fragmentation. over a UDP datagram will generally avoid IP fragmentation.
Figure 6 shows a POST request to signal that ports 80, 8080, and 443 Figure 6 shows a POST request to signal that ports 80, 8080, and 443
on the servers 2002:db8:6401::1 and 2002:db8:6401::2 are being on the servers 2002:db8:6401::1 and 2002:db8:6401::2 are being
attacked. attacked.
POST coaps://www.example.com/.well-known/v1/DOTS signal Header: POST (Code=0.02)
Accept: application/json Uri-Host: "www.example.com"
Content-Format: application/json Uri-Path: ".well-known"
Uri-Path: "v1"
Uri-Path: "DOTS-signal"
Content-Type: "application/json"
{ {
"policy-id":123321333242, "policy-id":123321333242,
"target-ip":[ "target-ip":[
"2002:db8:6401::1", "2002:db8:6401::1",
"2002:db8:6401::2" "2002:db8:6401::2"
], ],
"target-port":[ "target-port":[
"80", "80",
"8080", "8080",
"443" "443"
], ],
"target-protocol":"tcp" "target-protocol":"tcp"
} }
Figure 6: POST for DOTS signal Figure 6: POST for DOTS signal
The DOTS server indicates the result of processing the POST request The DOTS server indicates the result of processing the POST request
using CoAP response codes. CoAP 2xx codes are success, CoAP 4xx using CoAP response codes. CoAP 2xx codes are success, CoAP 4xx
codes are some sort of invalid request and 5xx codes are returned if codes are some sort of invalid request and 5xx codes are returned if
the DOTS server has erred or is incapable of performing the the DOTS server has erred or is incapable of performing the
mitigation. Response code 2.01 (Created) will be returned in the mitigation. Response code 2.01 (Created) will be returned in the
response if the DOTS server has accepted the mitigation request and response if the DOTS server has accepted the mitigation request and
will try to mitigate the attack. If the request is missing one or will try to mitigate the attack. If the request is missing one or
more mandatory attributes then 4.00 (Bad Request) will be returned in more mandatory attributes then 4.00 (Bad Request) will be returned in
the response or if the request contains invalid or unknown parameters the response or if the request contains invalid or unknown parameters
then 4.02 (Invalid query) will be returned in the response. The CoAP then 4.02 (Invalid query) will be returned in the response. The CoAP
response will include the JSON body received in the request. response will include the JSON body received in the request.
5.2.2. Withdraw a DOTS Signal 5.2.2. Withdraw a DOTS Signal
A DELETE request is used to withdraw a DOTS signal from a DOTS server A DELETE request is used to withdraw a DOTS signal from a DOTS server
(Figure 7). (Figure 7).
DELETE {scheme}://{host}:{port}/.well-known/{URI suffix for DOTS signal} Header: DELETE (Code=0.04)
Accept: application/json Uri-Host: "host"
Content-Format: application/json Uri-Path: ".well-known"
{ Uri-Path: "version"
"policy-id": "number" Uri-Path: "DOTS-signal"
} Content-Type: "application/json"
{
"policy-id": "number"
}
Figure 7: Withdraw DOTS signal Figure 7: Withdraw DOTS signal
If the DOTS server does not find the policy number conveyed in the If the DOTS server does not find the policy number conveyed in the
DELETE request in its policy state data, then it responds with a 4.04 DELETE request in its policy state data, then it responds with a 4.04
(Not Found) error response code. The DOTS server successfully (Not Found) error response code. The DOTS server successfully
acknowledges a DOTS client's request to withdraw the DOTS signal acknowledges a DOTS client's request to withdraw the DOTS signal
using 2.02 (Deleted) response code, and ceases mitigation activity as using 2.02 (Deleted) response code, and ceases mitigation activity as
quickly as possible. quickly as possible.
5.2.3. Retrieving a DOTS Signal 5.2.3. Retrieving a DOTS Signal
A GET request is used to retrieve information and status of a DOTS A GET request is used to retrieve information and status of a DOTS
signal from a DOTS server (Figure 8). If the DOTS server does not signal from a DOTS server (Figure 8). If the DOTS server does not
find the policy number conveyed in the GET request in its policy find the policy number conveyed in the GET request in its policy
state data, then it responds with a 4.04 (Not Found) error response state data, then it responds with a 4.04 (Not Found) error response
code. code.
1) To retrieve all DOTS signals signaled by the DOTS client. 1) To retrieve all DOTS signals signaled by the DOTS client.
GET {scheme}://{host}:{port}/.well-known/{URI suffix for DOTS signal}/list Header: GET (Code=0.01)
Observe : 0 Uri-Host: "host"
Uri-Path: ".well-known"
Uri-Path: "version"
Uri-Path: "DOTS-signal"
Uri-Path: "list"
Observe : 0
2) To retrieve a specific DOTS signal signaled by the DOTS client. 2) To retrieve a specific DOTS signal signaled by the DOTS client.
The policy information in the response will be formatted in the The policy information in the response will be formatted in the
same order it was processed at the DOTS server. same order it was processed at the DOTS server.
GET {scheme}://{host}:{port}/.well-known/{URI suffix for DOTS signal}/<policy-id number> Header: GET (Code=0.01)
Observe : 0 Uri-Host: "host"
Uri-Path: ".well-known"
Uri-Path: "version"
Uri-Path: "DOTS-signal"
Uri-Path: "policy-id value"
Observe : 0
Figure 8: GET to retrieve the rules Figure 8: GET to retrieve the rules
Figure 9 shows the response of all the active policies on the DOTS Figure 9 shows the response of all the active policies on the DOTS
server. server.
{ {
"policy-data":[ "policy-data":[
{ {
"policy-id":123321333242, "policy-id":123321333242,
"target-prtoocol":"tcp", "target-protocol":"tcp",
"lifetime":3600, "lifetime":3600,
"status":"mitigation in progress" "status":"mitigation in progress"
}, },
{ {
"policy-id":123321333244, "policy-id":123321333244,
"target-protocol":"udp", "target-protocol":"udp",
"lifetime":1800, "lifetime":1800,
"status":"mitigation complete" "status":"mitigation complete"
}, },
{ {
skipping to change at page 13, line 51 skipping to change at page 14, line 51
The observe option defined in [RFC7641] extends the CoAP core The observe option defined in [RFC7641] extends the CoAP core
protocol with a mechanism for a CoAP client to "observe" a resource protocol with a mechanism for a CoAP client to "observe" a resource
on a CoAP server: the client retrieves a representation of the on a CoAP server: the client retrieves a representation of the
resource and requests this representation be updated by the server as resource and requests this representation be updated by the server as
long as the client is interested in the resource. A DOTS client long as the client is interested in the resource. A DOTS client
conveys the observe option set to 0 in the GET request to receive conveys the observe option set to 0 in the GET request to receive
unsolicited notifications of attack mitigation status from the DOTS unsolicited notifications of attack mitigation status from the DOTS
server. Unidirectional notifications within the bidirectional signal server. Unidirectional notifications within the bidirectional signal
channel allows unsolicited message delivery, enabling asynchronous channel allows unsolicited message delivery, enabling asynchronous
notifications between the agents. notifications between the agents. A DOTS client that is no longer
interested in receiving notifications from the DOTS server can simply
"forget" the observation. When the DOTS server then sends the next
notification, the DOTS client will not recognize the token in the
message and thus will return a Reset message. This causes the DOTS
server to remove the associated entry.
DOTS Client DOTS Server DOTS Client DOTS Server
| | | |
| GET /<policy-id number> | | GET /<policy-id number> |
| Token: 0x4a | Registration | Token: 0x4a | Registration
| Observe: 0 | | Observe: 0 |
+-------------------------->| +-------------------------->|
| | | |
| 2.05 Content | | 2.05 Content |
| Token: 0x4a | Notification of | Token: 0x4a | Notification of
skipping to change at page 15, line 16 skipping to change at page 16, line 16
While DDoS mitigation is active, a DOTS client MAY frequently While DDoS mitigation is active, a DOTS client MAY frequently
transmit DOTS mitigation efficacy updates to the relevant DOTS transmit DOTS mitigation efficacy updates to the relevant DOTS
server. An PUT request (Figure 11) is used to convey the mitigation server. An PUT request (Figure 11) is used to convey the mitigation
efficacy update to the DOTS server. The PUT request MUST include all efficacy update to the DOTS server. The PUT request MUST include all
the header fields used in the POST request to convey the DOTS signal the header fields used in the POST request to convey the DOTS signal
(Section 5.2.1). If the DOTS server does not find the policy number (Section 5.2.1). If the DOTS server does not find the policy number
conveyed in the PUT request in its policy state data, it responds conveyed in the PUT request in its policy state data, it responds
with a 4.04 (Not Found) error response code. with a 4.04 (Not Found) error response code.
PUT {scheme}://{host}:{port}/.well-known/{URI suffix for DOTS signal}/<policy-id number> Header: PUT (Code=0.03)
Accept: application/json Uri-Host: "host"
Content-Format: application/json Uri-Path: ".well-known"
{ Uri-Path: "version"
"target-ip": "string", Uri-Path: "DOTS-signal"
"target-port": "string", Uri-Path: "policy-id value"
"target-protocol": "string", Content-Type: "application/json"
"lifetime": "number", {
"attack-status": "string" "target-ip": "string",
} "target-port": "string",
"target-protocol": "string",
"lifetime": "number",
"attack-status": "string"
}
Figure 11: Efficacy Update Figure 11: Efficacy Update
The 'attack-status' field is a mandatory attribute. The various The 'attack-status' field is a mandatory attribute. The various
possible values contained in the 'attack-status' field are explained possible values contained in the 'attack-status' field are explained
below: below:
in-progress: DOTS client determines that it is still under attack. in-progress: DOTS client determines that it is still under attack.
terminated: Attack is successfully mitigated (e.g., attack traffic terminated: Attack is successfully mitigated (e.g., attack traffic
is dropped). is dropped).
6. DOTS Data Channel 6. DOTS Data Channel
The data channel is intended to be used for bulk data exchanges and Note: Based on discussions at IETF-96 DOTS implementers meeting, in
requires a reliable transport, CoAP over TLS over TCP is used for later revision this section becomes its own stand-alone specification
data channel. and will include https://tools.ietf.org/html/draft-nishizuka-dots-
inter-domain-mechanism-01.
The DOTS data channel is intended to be used for bulk data exchanges
between DOTS agents. Unlike the signal channel, which must operate
nominally even when confronted with despite signal degradation due to
packet loss, the data channel is not expected to be constructed to
deal with attack conditions. As the primary function of the data
channel is data exchange, a reliable transport is required in order
for DOTS agents to detect data delivery success or failure. CoAP
over TLS over TCP is used for DOTS data channel.
+--------------+
| DOTS |
+--------------+
| CoAP |
+--------------+
| TLS |
+--------------+
| TCP |
+--------------+
| IP |
+--------------+
Figure 12: Abstract Layering of DOTS data channel over CoAP over TLS
JSON payloads is used to convey both filtering rules as well as data JSON payloads is used to convey both filtering rules as well as data
channel specific payload messages that convey request parameters and channel specific payload messages that convey request parameters and
response information such as errors. All data channel URIs defined response information such as errors. All data channel URIs defined
in this document, and in subsequent documents, MUST NOT have a URI in this document, and in subsequent documents, MUST NOT have a URI
containing "/DOTS signal". containing "/DOTS-signal".
One of the possible arrangements for DOTS client to signal filtering One of the possible arrangements for DOTS client to signal filtering
rules to a DOTS server via the DOTS gateway is discussed below: rules to a DOTS server via the DOTS gateway is discussed below:
The DOTS conveys the black-list rules to the DOTS gateway. The DOTS The DOTS data channel conveys the filtering rules to the DOTS
gateway validates if the DOTS client is authorized to signal the gateway. The DOTS gateway validates if the DOTS client is authorized
black-list rules and if the client is authorized propagates the rules to signal the filtering rules and if the client is authorized
to the DOTS server. Likewise, the DOTS server validates if the DOTS propagates the rules to the DOTS server. Likewise, the DOTS server
gateway is authorized to signal the black-list rules. To create or validates if the DOTS gateway is authorized to signal the filtering
purge filters, the DOTS client sends CoAP requests to the DOTS rules. To create or purge filters, the DOTS client sends CoAP
gateway. The DOTS gateway acts as a proxy, validates the rules and requests to the DOTS gateway. The DOTS gateway acts as a proxy,
proxies the requests containing the black-listed IP addresses to a validates the rules and proxies the requests containing the filtering
DOTS server. When the DOTS gateway receives the associated CoAP rules to a DOTS server. When the DOTS gateway receives the
response from the DOTS server, it propagates the response back to the associated CoAP response from the DOTS server, it propagates the
DOTS client. If an attack is detected by the DOTS gateway then it response back to the DOTS client.
can act as a DOTS client and signal the black-list rules to the DOTS
server. The DOTS gateway plays the role of both client and server.
6.1. Filtering Rules 6.1. Filtering Rules
The following APIs define means for a DOTS client to configure The following APIs define means for a DOTS client to configure
filtering rules on a DOTS server. filtering rules on a DOTS server.
6.1.1. Install Filtering Rules 6.1.1. Install Filtering Rules
An POST request is used to push filtering rules to a DOTS server An POST request is used to push filtering rules to a DOTS server
(Figure 12). (Figure 13).
POST {scheme}://{host}:{port}/.well-known/{version}/{URI suffix for filtering} Header: POST (Code=0.02)
Accept: application/json Uri-Host: "host"
Content-Format: application/json Uri-Path: ".well-known"
{ Uri-Path: "version"
"policy-id": "number", Uri-Path: "DOTS-data-channel"
"traffic-protocol": "string", Content-Type: "application/json"
"source-protocol-port": "string", {
"destination-protocol-port": "string", "policy-id": "integer",
"destination-ip": "string", "traffic-protocol": "string",
"source-ip": "string", "source-protocol-port": "string",
"lifetime": "number", "destination-protocol-port": "string",
"traffic-rate" : "number" "destination-ip": "string",
} "source-ip": "string",
"lifetime": "number",
"traffic-rate" : "number"
}
Figure 12: POST to install filtering rules Figure 13: POST to install filtering rules
The header fields are described below: The header fields are described below:
policy-id: Identifier of the policy represented using a number. policy-id: Identifier of the policy represented using a integer.
This identifier MUST be unique for each policy bound to the DOTS This identifier MUST be unique for each policy bound to the DOTS
client, i.e., the policy-id needs to be unique relative to the client, i.e., the policy-id needs to be unique relative to the
active policies with the DOTS server. This identifier must be active policies with the DOTS server. This identifier must be
generated by the client. This document does not make any generated by the client. This document does not make any
assumption about how this identifier is generated. This is an assumption about how this identifier is generated. This is an
mandatory attribute. mandatory attribute.
traffic-protocol: Valid protocol values include tcp, udp, sctp, and traffic-protocol: Valid protocol values include tcp, udp, sctp, and
dccp. This is an mandatory attribute. dccp. Protocol values are seperated by commas (e.g. "tcp, udp").
This is an mandatory attribute.
source-protocol-port: The source port number, port number range source-protocol-port: The source port number. Ports are seperated
(using "-"). For TCP, UDP, SCTP, or DCCP: the source range of by commas and port number range (using "-"). For TCP, UDP, SCTP,
ports (e.g., 1024-65535). This is an optional attribute. or DCCP: the source range of ports (e.g., 1024-65535). This is an
optional attribute.
destination-protocol-port: The destination port number, port number destination-protocol-port: The destination port number. Ports are
range (using "-"). For TCP, UDP, SCTP, or DCCP: the destination seperated by commas and port number range (using "-"). For TCP,
range of ports (e.g., 443-443). This information is useful to UDP, SCTP, or DCCP: the destination range of ports (e.g.,
avoid disturbing a group of customers when address sharing is in 443-443). This information is useful to avoid disturbing a group
use [RFC6269]. This is an optional attribute. of customers when address sharing is in use [RFC6269]. This is an
optional attribute.
destination-ip: The destination IP address, IP addresses separated destination-ip: The destination IP address or prefix. IP addresses
by commas, or prefixes using "/" notation. This is an optional and prefixes are separated by commas. Prefixes are represented
attribute. using CIDR notation. This is an optional attribute.
source-ip: The source IP addresses, IP addresses separated by source-ip: The source IP addresses or prefix. IP addresses and
commas, or prefixes using "/" notation. This is an optional prefixes are separated by commas. Prefixes are represented using
attribute. CIDR notation. This is an optional attribute.
lifetime: Lifetime of the rule in seconds. Upon the expiry of this lifetime: Lifetime of the rule in seconds. Upon the expiry of this
lifetime, and if the request is not refreshed, this particular lifetime, and if the request is not refreshed, this particular
rule is removed. The rule can be refreshed by sending the same rule is removed. The rule can be refreshed by sending the same
message again. The default lifetime of the rule is 60 minutes -- message again. The default lifetime of the rule is 60 minutes --
this value was chosen to be long enough so that refreshing is not this value was chosen to be long enough so that refreshing is not
typically a burden on the DOTS client, while expiring the rule typically a burden on the DOTS client, while expiring the rule
where the client has unexpectedly quit in a timely manner. A where the client has unexpectedly quit in a timely manner. A
lifetime of zero indicates indefinite lifetime for the rule. The lifetime of zero indicates indefinite lifetime for the rule. The
server MUST always indicate the actual lifetime in the response. server MUST always indicate the actual lifetime in the response.
skipping to change at page 17, line 49 skipping to change at page 19, line 36
traffic-rate: This is the allowed traffic rate in bytes per second traffic-rate: This is the allowed traffic rate in bytes per second
indicated in IEEE floating point [IEEE.754.1985] format. The indicated in IEEE floating point [IEEE.754.1985] format. The
value 0 indicates all traffic for the particular flow to be value 0 indicates all traffic for the particular flow to be
discarded. This is a mandatory attribute. discarded. This is a mandatory attribute.
The relative order of two rules is determined by comparing their The relative order of two rules is determined by comparing their
respective policy identifiers. The rule with lower numeric policy respective policy identifiers. The rule with lower numeric policy
identifier value has higher precedence (and thus will match before) identifier value has higher precedence (and thus will match before)
than the rule with higher numeric policy identifier value. than the rule with higher numeric policy identifier value.
Figure 13 shows a POST request to block traffic from attacker IPv6 Figure 14 shows a POST request to block traffic from attacker IPv6
prefix 2001:db8:abcd:3f01::/64 to network resource using IPv6 address prefix 2001:db8:abcd:3f01::/64 to network resource using IPv6 address
2002:db8:6401::1 to operate a server on TCP port 443. 2002:db8:6401::1 to operate a server on TCP port 443.
POST coaps://www.example.com/.well-known/v1/filter Header: POST (Code=0.02)
Accept: application/json Uri-Host: "www.example.com"
Content-Format: application/json Uri-Path: ".well-known"
Uri-Path: "v1"
Uri-Path: "DOTS-data-channel"
Content-Type: "application/json"
{ {
"policy-id": 123321333242, "policy-id": 123321333242,
"traffic-protocol": "tcp", "traffic-protocol": "tcp",
"source-protocol-port": "0-65535", "source-protocol-port": "0-65535",
"destination-protocol-port": "443", "destination-protocol-port": "443",
"destination-ip": "2001:db8:abcd:3f01::/64", "destination-ip": "2001:db8:abcd:3f01::/64",
"source-ip": "2002:db8:6401::1", "source-ip": "2002:db8:6401::1",
"lifetime": 1800, "lifetime": 1800,
"traffic-rate": 0 "traffic-rate": 0
} }
Figure 13: POST to Install Black-list Rules Figure 14: POST to Install Black-list Rules
6.1.2. Remove Filtering Rules 6.1.2. Remove Filtering Rules
A DELETE request is used to delete filtering rules from a DOTS server A DELETE request is used to delete filtering rules from a DOTS server
(Figure 14). (Figure 15).
DELETE {scheme}://{host}:{port}/.well-known/{URI suffix for filtering} Header: DELETE (Code=0.04)
Accept: application/json Uri-Host: "host"
Content-Format: application/json Uri-Path: ".well-known"
{ Uri-Path: "version"
"policy-id": "number" Uri-Path: "DOTS-data-channel"
} Content-Type: "application/json"
{
"policy-id": "number"
}
Figure 14: DELETE to remove the rules Figure 15: DELETE to remove the rules
6.1.3. Retrieving Installed Filtering Rules 6.1.3. Retrieving Installed Filtering Rules
A GET request is used to retrieve filtering rules from a DOTS server. The DOTS client periodically queries the DOTS server to check the
counters for installed filtering rules. A GET request is used to
retrieve filtering rules from a DOTS server.
Figure 15 shows an example to retrieve all the black-lists rules Figure 16 shows an example to retrieve all the filtering rules
programmed by the DOTS client while Figure 16 shows an example to programmed by the DOTS client while Figure 17 shows an example to
retrieve specific black-list rules programmed by the DOTS client. retrieve specific filtering rules programmed by the DOTS client.
GET {scheme}://{host}:{port}/.well-known/{URI suffix for filtering} Header: GET (Code=0.01)
Uri-Host: "host"
Uri-Path: ".well-known"
Uri-Path: "version"
Uri-Path: "DOTS-data-channel"
Uri-Path: "list"
Figure 15: GET to retrieve the rules (1) Figure 16: GET to retrieve the rules (1)
Header: GET (Code=0.01)
Uri-Host: "host"
Uri-Path: ".well-known"
Uri-Path: "version"
Uri-Path: "DOTS-data-channel"
Uri-Path: "policy-id value"
Figure 17: GET to retrieve the rules (2)
Figure 18 shows response for all active policies on the DOTS server.
GET {scheme}://{host}:{port}/.well-known/{URI suffix for filtering}
Accept: application/json
Content-Format: application/json
{ {
"policy-id": "number" "policy-data":[
{
"policy-id":123321333242,
"traffic-protocol": "tcp",
"source-protocol-port": "0-65535",
"destination-protocol-port": "443",
"destination-ip": "2001:db8:abcd:3f01::/64",
"source-ip": "2002:db8:6401::1",
"lifetime": 1800,
"traffic-rate": 0,
"match-count": 689324,
},
{
"policy-id":123321333242,
"traffic-protocol": "udp",
"source-protocol-port": "0-65535",
"destination-protocol-port": "53",
"destination-ip": "2001:db8:abcd:3f01::/64",
"source-ip": "2002:db8:6401::2",
"lifetime": 1800,
"traffic-rate": 0,
"match-count": 6666,
}
]
} }
Figure 16: GET to retrieve the rules (2) Figure 18: Response body
TODO: show response
7. (D)TLS Protocol Profile and Performance considerations 7. (D)TLS Protocol Profile and Performance considerations
This section defines the (D)TLS protocol profile of DOTS signal This section defines the (D)TLS protocol profile of DOTS signal
channel over (D)TLS and DOTS data channel over TLS. channel over (D)TLS and DOTS data channel over TLS.
There are known attacks on (D)TLS, such as machine-in-the-middle and There are known attacks on (D)TLS, such as machine-in-the-middle and
protocol downgrade. These are general attacks on (D)TLS and not protocol downgrade. These are general attacks on (D)TLS and not
specific to DOTS over (D)TLS; please refer to the (D)TLS RFCs for specific to DOTS over (D)TLS; please refer to the (D)TLS RFCs for
discussion of these security issues. DOTS agents MUST adhere to the discussion of these security issues. DOTS agents MUST adhere to the
skipping to change at page 19, line 37 skipping to change at page 22, line 26
DOTS using (D)TLS is virtually a green-field deployment DOTS agents DOTS using (D)TLS is virtually a green-field deployment DOTS agents
MUST implement only (D)TLS 1.2 or later. MUST implement only (D)TLS 1.2 or later.
Implementations compliant with this profile MUST implement all of the Implementations compliant with this profile MUST implement all of the
following items: following items:
o DOTS client can use (D)TLS session resumption without server-side o DOTS client can use (D)TLS session resumption without server-side
state [RFC5077] to resume session and convey the DOTS signal. state [RFC5077] to resume session and convey the DOTS signal.
o While the communication to the DOTS server is quiescent, the DOTS o While the communication to the DOTS server is quiescent, the DOTS
client may want to probe the server to ensure it has maintained client MAY probe the server to ensure it has maintained
cryptographic state. Such probes can also keep alive firewall or cryptographic state. Such probes can also keep alive firewall or
NAT bindings. This probing reduces the frequency of needing a new NAT bindings. This probing reduces the frequency of needing a new
handshake when a DOTS signal needs to be conveyed to the DOTS handshake when a DOTS signal needs to be conveyed to the DOTS
server. server.
* A (D)TLS heartbeat [RFC6520] verifies the DOTS server still has * A (D)TLS heartbeat [RFC6520] verifies the DOTS server still has
DTLS state by returning a DTLS message. If the server has lost DTLS state by returning a DTLS message. If the server has lost
state, it returns a DTLS Alert. Upon receipt of an state, it returns a DTLS Alert. Upon receipt of an
unauthenticated DTLS Alert, the DTLS client validates the Alert unauthenticated DTLS Alert, the DTLS client validates the Alert
is within the replay window (Section 4.1.2.6 of [RFC6347]). It is within the replay window (Section 4.1.2.6 of [RFC6347]). It
skipping to change at page 20, line 40 skipping to change at page 23, line 31
o TCP Fast Open [RFC7413] can reduce the number of round-trips to o TCP Fast Open [RFC7413] can reduce the number of round-trips to
convey DOTS signal. convey DOTS signal.
8. Mutual Authentication of DOTS Agents & Authorization of DOTS Clients 8. Mutual Authentication of DOTS Agents & Authorization of DOTS Clients
(D)TLS based on client certificate can be used for mutual (D)TLS based on client certificate can be used for mutual
authentication between DOTS agents. If a DOTS gateway is involved, authentication between DOTS agents. If a DOTS gateway is involved,
DOTS clients and DOTS gateway MUST perform mutual authentication; DOTS clients and DOTS gateway MUST perform mutual authentication;
only authorized DOTS clients are allowed to send DOTS signals to a only authorized DOTS clients are allowed to send DOTS signals to a
DOTS server. DOTS gateway. DOTS gateway and DOTS server MUST perform mutual
authentication; DOTS server only allows DOTS signals from authorized
DOTS gateway, creating a two-link chain of transitive authentication
between the DOTS client and the DOTS server.
+-------------------------------------------------+ +-------------------------------------------------+
| example.com domain +---------+ | | example.com domain +---------+ |
| | AAA | | | | AAA | |
| +---------------+ | Server | | | +---------------+ | Server | |
| | Application | +------+--+ | | | Application | +------+--+ |
| | server + ^ | | server + ^
| | (DOTS client) |<-----------------+ | | | | (DOTS client) |<-----------------+ | |
| +---------------+ + | | example.net domain | +---------------+ + | | example.net domain
| V V | | V V |
skipping to change at page 21, line 29 skipping to change at page 24, line 29
| +----+--------+ | +---------------+ | +----+--------+ | +---------------+
| ^ | | ^ |
| | | | | |
| +----------------+ | | | +----------------+ | |
| | DDOS detector | | | | | DDOS detector | | |
| | (DOTS client) +<--------------+ | | | (DOTS client) +<--------------+ |
| +----------------+ | | +----------------+ |
| | | |
+-------------------------------------------------+ +-------------------------------------------------+
Figure 17: Example of Authentication and Authorization of DOTS Agents Figure 19: Example of Authentication and Authorization of DOTS Agents
In the example depicted in Figure 17, the DOTS gateway and DOTS In the example depicted in Figure 19, the DOTS gateway and DOTS
clients within the 'example.com' domain mutually authenticate with clients within the 'example.com' domain mutually authenticate with
each other. After the DOTS gateway validates the identity of a DOTS each other. After the DOTS gateway validates the identity of a DOTS
client, it communicates with the AAA server in the 'example.com' client, it communicates with the AAA server in the 'example.com'
domain to determine if the DOTS client is authorized to request DDOS domain to determine if the DOTS client is authorized to request DDOS
mitigation. If the DOTS client is not authorized, a 4.01 mitigation. If the DOTS client is not authorized, a 4.01
(Unauthorized) is returned in the response to the DOTS client. In (Unauthorized) is returned in the response to the DOTS client. In
this example, the DOTS gateway only allows the application server and this example, the DOTS gateway only allows the application server and
DDOS detector to request DDOS mitigation, but does not permit the DDOS detector to request DDOS mitigation, but does not permit the
user of type 'guest' to request DDOS mitigation. user of type 'guest' to request DDOS mitigation.
Also, DOTS gateway and DOTS server MUST perform mutual authentication Also, DOTS gateway and DOTS server MUST perform mutual authentication
using certificates. A DOTS server will only allow a DOTS gateway using certificates. A DOTS server will only allow a DOTS gateway
with a certificate for a particular domain to request mitigation for with a certificate for a particular domain to request mitigation for
that domain. In reference to Figure 17, the DOTS server only allows that domain. In reference to Figure 19, the DOTS server only allows
the DOTS gateway to request mitigation for 'example.com' domain and the DOTS gateway to request mitigation for 'example.com' domain and
not for other domains. not for other domains.
9. IANA Considerations 9. IANA Considerations
TODO TODO
[TBD: DOTS WG will probably have to do something similar to
https://tools.ietf.org/html/rfc7519#section-10, create JSON DOTS
claim registry and register the JSON attributes defined in this
specification].
10. Security Considerations 10. Security Considerations
Authenticated encryption MUST be used for data confidentiality and Authenticated encryption MUST be used for data confidentiality and
message integrity. (D)TLS based on client certificate MUST be used message integrity. (D)TLS based on client certificate MUST be used
for mutual authentication. The interaction between the DOTS agents for mutual authentication. The interaction between the DOTS agents
requires Datagram Transport Layer Security (DTLS) and Transport Layer requires Datagram Transport Layer Security (DTLS) and Transport Layer
Security (TLS) with a ciphersuite offering confidentiality protection Security (TLS) with a ciphersuite offering confidentiality protection
and the guidance given in [RFC7525] MUST be followed to avoid attacks and the guidance given in [RFC7525] MUST be followed to avoid attacks
on (D)TLS. on (D)TLS.
skipping to change at page 22, line 41 skipping to change at page 25, line 46
network). network).
Involved functional elements in the cooperation system must establish Involved functional elements in the cooperation system must establish
exchange instructions and notification over a secure and exchange instructions and notification over a secure and
authenticated channel. Adequate filters can be enforced to avoid authenticated channel. Adequate filters can be enforced to avoid
that nodes outside a trusted domain can inject request such as that nodes outside a trusted domain can inject request such as
deleting filtering rules. Nevertheless, attacks can be initiated deleting filtering rules. Nevertheless, attacks can be initiated
from within the trusted domain if an entity has been corrupted. from within the trusted domain if an entity has been corrupted.
Adequate means to monitor trusted nodes should also be enabled. Adequate means to monitor trusted nodes should also be enabled.
11. Acknowledgements 11. Contributors
Robert Moskowitz
12. Acknowledgements
Thanks to Christian Jacquenet, Roland Dobbins, Andrew Mortensen, Thanks to Christian Jacquenet, Roland Dobbins, Andrew Mortensen,
Roman D. Danyliw, and Gilbert Clark for the discussion and comments. Roman D. Danyliw, and Gilbert Clark for the discussion and comments.
12. References 13. References
12.1. Normative References 13.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246, (TLS) Protocol Version 1.2", RFC 5246,
DOI 10.17487/RFC5246, August 2008, DOI 10.17487/RFC5246, August 2008,
<http://www.rfc-editor.org/info/rfc5246>. <http://www.rfc-editor.org/info/rfc5246>.
skipping to change at page 23, line 45 skipping to change at page 27, line 5
"Recommendations for Secure Use of Transport Layer "Recommendations for Secure Use of Transport Layer
Security (TLS) and Datagram Transport Layer Security Security (TLS) and Datagram Transport Layer Security
(DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May (DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May
2015, <http://www.rfc-editor.org/info/rfc7525>. 2015, <http://www.rfc-editor.org/info/rfc7525>.
[RFC7641] Hartke, K., "Observing Resources in the Constrained [RFC7641] Hartke, K., "Observing Resources in the Constrained
Application Protocol (CoAP)", RFC 7641, Application Protocol (CoAP)", RFC 7641,
DOI 10.17487/RFC7641, September 2015, DOI 10.17487/RFC7641, September 2015,
<http://www.rfc-editor.org/info/rfc7641>. <http://www.rfc-editor.org/info/rfc7641>.
12.2. Informative References 13.2. Informative References
[I-D.ietf-dots-architecture]
Mortensen, A., Andreasen, F., Reddy, T.,
christopher_gray3@cable.comcast.com, c., Compton, R., and
N. Teague, "Distributed-Denial-of-Service Open Threat
Signaling (DOTS) Architecture", draft-ietf-dots-
architecture-00 (work in progress), July 2016.
[I-D.ietf-dots-requirements] [I-D.ietf-dots-requirements]
Mortensen, A., Moskowitz, R., and T. Reddy, "Distributed Mortensen, A., Moskowitz, R., and T. Reddy, "Distributed
Denial of Service (DDoS) Open Threat Signaling Denial of Service (DDoS) Open Threat Signaling
Requirements", draft-ietf-dots-requirements-01 (work in Requirements", draft-ietf-dots-requirements-02 (work in
progress), July 2016.
[I-D.ietf-dots-use-cases]
Dobbins, R., Fouant, S., Migault, D., Moskowitz, R.,
Teague, N., and L. Xia, "Use cases for DDoS Open Threat
Signaling", draft-ietf-dots-use-cases-01 (work in
progress), March 2016. progress), March 2016.
[I-D.ietf-tls-cached-info] [I-D.ietf-tls-cached-info]
Santesson, S. and H. Tschofenig, "Transport Layer Security Santesson, S. and H. Tschofenig, "Transport Layer Security
(TLS) Cached Information Extension", draft-ietf-tls- (TLS) Cached Information Extension", draft-ietf-tls-
cached-info-23 (work in progress), May 2016. cached-info-23 (work in progress), May 2016.
[I-D.ietf-tls-falsestart] [I-D.ietf-tls-falsestart]
Langley, A., Modadugu, N., and B. Moeller, "Transport Langley, A., Modadugu, N., and B. Moeller, "Transport
Layer Security (TLS) False Start", draft-ietf-tls- Layer Security (TLS) False Start", draft-ietf-tls-
skipping to change at page 24, line 24 skipping to change at page 27, line 45
[IEEE.754.1985] [IEEE.754.1985]
Institute of Electrical and Electronics Engineers, Institute of Electrical and Electronics Engineers,
"Standard for Binary Floating-Point Arithmetic", August "Standard for Binary Floating-Point Arithmetic", August
1985. 1985.
[RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, [RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791,
DOI 10.17487/RFC0791, September 1981, DOI 10.17487/RFC0791, September 1981,
<http://www.rfc-editor.org/info/rfc791>. <http://www.rfc-editor.org/info/rfc791>.
[RFC4632] Fuller, V. and T. Li, "Classless Inter-domain Routing
(CIDR): The Internet Address Assignment and Aggregation
Plan", BCP 122, RFC 4632, DOI 10.17487/RFC4632, August
2006, <http://www.rfc-editor.org/info/rfc4632>.
[RFC4732] Handley, M., Ed., Rescorla, E., Ed., and IAB, "Internet [RFC4732] Handley, M., Ed., Rescorla, E., Ed., and IAB, "Internet
Denial-of-Service Considerations", RFC 4732, Denial-of-Service Considerations", RFC 4732,
DOI 10.17487/RFC4732, December 2006, DOI 10.17487/RFC4732, December 2006,
<http://www.rfc-editor.org/info/rfc4732>. <http://www.rfc-editor.org/info/rfc4732>.
[RFC4987] Eddy, W., "TCP SYN Flooding Attacks and Common [RFC4987] Eddy, W., "TCP SYN Flooding Attacks and Common
Mitigations", RFC 4987, DOI 10.17487/RFC4987, August 2007, Mitigations", RFC 4987, DOI 10.17487/RFC4987, August 2007,
<http://www.rfc-editor.org/info/rfc4987>. <http://www.rfc-editor.org/info/rfc4987>.
[RFC5077] Salowey, J., Zhou, H., Eronen, P., and H. Tschofenig, [RFC5077] Salowey, J., Zhou, H., Eronen, P., and H. Tschofenig,
"Transport Layer Security (TLS) Session Resumption without "Transport Layer Security (TLS) Session Resumption without
Server-Side State", RFC 5077, DOI 10.17487/RFC5077, Server-Side State", RFC 5077, DOI 10.17487/RFC5077,
January 2008, <http://www.rfc-editor.org/info/rfc5077>. January 2008, <http://www.rfc-editor.org/info/rfc5077>.
[RFC5575] Marques, P., Sheth, N., Raszuk, R., Greene, B., Mauch, J., [RFC5575] Marques, P., Sheth, N., Raszuk, R., Greene, B., Mauch, J.,
and D. McPherson, "Dissemination of Flow Specification and D. McPherson, "Dissemination of Flow Specification
Rules", RFC 5575, DOI 10.17487/RFC5575, August 2009, Rules", RFC 5575, DOI 10.17487/RFC5575, August 2009,
<http://www.rfc-editor.org/info/rfc5575>. <http://www.rfc-editor.org/info/rfc5575>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<http://www.rfc-editor.org/info/rfc6241>.
[RFC6269] Ford, M., Ed., Boucadair, M., Durand, A., Levis, P., and [RFC6269] Ford, M., Ed., Boucadair, M., Durand, A., Levis, P., and
P. Roberts, "Issues with IP Address Sharing", RFC 6269, P. Roberts, "Issues with IP Address Sharing", RFC 6269,
DOI 10.17487/RFC6269, June 2011, DOI 10.17487/RFC6269, June 2011,
<http://www.rfc-editor.org/info/rfc6269>. <http://www.rfc-editor.org/info/rfc6269>.
[RFC6520] Seggelmann, R., Tuexen, M., and M. Williams, "Transport [RFC6520] Seggelmann, R., Tuexen, M., and M. Williams, "Transport
Layer Security (TLS) and Datagram Transport Layer Security Layer Security (TLS) and Datagram Transport Layer Security
(DTLS) Heartbeat Extension", RFC 6520, (DTLS) Heartbeat Extension", RFC 6520,
DOI 10.17487/RFC6520, February 2012, DOI 10.17487/RFC6520, February 2012,
<http://www.rfc-editor.org/info/rfc6520>. <http://www.rfc-editor.org/info/rfc6520>.
skipping to change at page 25, line 22 skipping to change at page 29, line 9
<http://www.rfc-editor.org/info/rfc6724>. <http://www.rfc-editor.org/info/rfc6724>.
[RFC7159] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data [RFC7159] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
Interchange Format", RFC 7159, DOI 10.17487/RFC7159, March Interchange Format", RFC 7159, DOI 10.17487/RFC7159, March
2014, <http://www.rfc-editor.org/info/rfc7159>. 2014, <http://www.rfc-editor.org/info/rfc7159>.
[RFC7413] Cheng, Y., Chu, J., Radhakrishnan, S., and A. Jain, "TCP [RFC7413] Cheng, Y., Chu, J., Radhakrishnan, S., and A. Jain, "TCP
Fast Open", RFC 7413, DOI 10.17487/RFC7413, December 2014, Fast Open", RFC 7413, DOI 10.17487/RFC7413, December 2014,
<http://www.rfc-editor.org/info/rfc7413>. <http://www.rfc-editor.org/info/rfc7413>.
Appendix A. BGP
BGP defines a mechanism as described in [RFC5575] that can be used to
automate inter-domain coordination of traffic filtering, such as what
is required in order to mitigate DDoS attacks. However, support for
BGP in an access network does not guarantee that traffic filtering
will always be honored. Since a DOTS client will not receive an
acknowledgment for the filtering request, the DOTS client should
monitor and apply similar rules in its own network in cases where the
DOTS server is unable to enforce the filtering rules. In addition,
enforcement of filtering rules of BGP on Internet routers are usually
governed by the maximum number of data elements the routers can hold
as well as the number of events they are able to process in a given
unit of time.
Authors' Addresses Authors' Addresses
Tirumaleswar Reddy Tirumaleswar Reddy
Cisco Systems, Inc. Cisco Systems, Inc.
Cessna Business Park, Varthur Hobli Cessna Business Park, Varthur Hobli
Sarjapur Marathalli Outer Ring Road Sarjapur Marathalli Outer Ring Road
Bangalore, Karnataka 560103 Bangalore, Karnataka 560103
India India
Email: tireddy@cisco.com Email: tireddy@cisco.com
skipping to change at page 26, line 31 skipping to change at line 1259
USA USA
Email: mgeller@cisco.com Email: mgeller@cisco.com
Mohamed Boucadair Mohamed Boucadair
Orange Orange
Rennes 35000 Rennes 35000
France France
Email: mohamed.boucadair@orange.com Email: mohamed.boucadair@orange.com
Robert Moskowitz
HTT Consulting
Oak Park, MI 42837
United States
Email: rgm@htt-consult.com
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