Network Working Group Barr Hibbs INTERNET-DRAFT (no affiliation) Category: Standards Track Glenn Waters Nortel Networks February 2004 Dynamic Host Configuration Protocol for IPv4 (DHCPv4) Server MIB Saved Friday, February 06, 2004, 4:33:38 PM Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or made obsolete by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/1id-abstracts.html. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. Copyright Notice Copyright (C), 2003, The Internet Society. All Rights Reserved. Abstract This memo defines an experimental portion of the Management Information Base (MIB) for use with network management protocols in the Internet Community. In particular, it defines objects used for the management of Dynamic Host Configuration Protocol for IPv4 (DHCPv4) and Bootstrap Protocol (BOOTP) servers. Hibbs & Waters Expires: August 2004 [Page 1] Internet Draft DHCPv4 Server MIB February 2004 Table of Contents 1. Introduction...................................................2 2. The Internet-Standard Management Framework.....................3 3. Overview.......................................................3 3.1. Relationship to Other MIBs.................................4 3.1.1. DHCP MIB Extensions....................................4 3.1.2. Host System MIB Extensions.............................4 3.1.3. DHCP Client MIB Extensions.............................4 3.1.4. DHCP Relay Agent MIB Extensions........................5 3.1.5. DHCPv6 MIB Extensions..................................5 3.2. Textual Conventions Introduced in this MIB.................5 3.2.1. Dhcpv4PhysicalAddress..................................5 3.3. BOOTP and DHCP Counter Groups..............................5 3.3.1. Discontinuities........................................6 3.3.2. Counter Rollover.......................................7 3.4. Server Configuration Group.................................7 4. Definitions....................................................9 5. Intellectual Property.........................................33 6. Acknowledgements..............................................33 7. IANA Considerations...........................................33 8. Security Considerations.......................................34 9. References....................................................35 9.1. Normative References......................................35 9.2. Informative References....................................35 10. Editors' Addresses...........................................36 11. Full Copyright Statement.....................................36 1. Introduction This memo is a product of the DHCP Working Group and defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it describes a set of extensions that DHCPv4 and Bootstrap Protocol (BOOTP) servers implement. Many implementations support both DHCPv4 and BOOTP within a single server and hence this memo describes the MIB for both DHCPv4 and BOOTP servers. This memo does not cover DHCPv4/BOOTP client nor relay agent MIB extensions: these are possibly the subjects of future investigation [see discussion in section 3.1.] Also excluded from this MIB extension in the interest of simplicity are DHCP Dynamic DNS Updating, Failover, Authentication, and Load Balancing: these functions and features could be subjects of future MIB extensions. Provision is also made for Standards-Track additions to the DHCP Message Type (option 61.) Hibbs & Waters Expires: August 2004 [Page 2] Internet Draft DHCPv4 Server MIB February 2004 This memo is based on the Internet-standard Network Management Framework as defined by documents [RFC2578, RFC2579, RFC2580]. Objects defined in this MIB allow access to and control of DHCP Server Software. Servers MAY also provide additional management capabilities using the Applications MIB [RFC2287]. The key words "MUST," "MUST NOT," "REQUIRED," "SHALL," "SHALL NOT," "SHOULD," "SHOULD NOT," "RECOMMENDED," "MAY," and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. 2. The Internet-Standard Management Framework For a detailed overview of the documents that describe the current Internet-Standard Management Framework, please refer to section 7 of RFC 3410 [RFC3410], Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB. MIB objects are generally accessed through the Simple Network Management Protocol (SNMP). Objects in the MIB are defined using the mechanisms defined in the Structure of Management Information (SMI). This memo specifies a MIB module that is compliant to the SMIv2, which is described in STD 58, [RFC2578], STD 58, [RFC2579] and STD 58, [RFC2580]. 3. Overview In the tradition of the Simple Network Management Protocol (SNMP), the minimum number of objects possible is defined in this MIB, while still providing as rich a set of management information as possible. An object is left out of this MIB when it can be derived from other objects that are provided. Further to the tradition of the SNMP, computationally intense operations are left to the domain of the management station. Thus, this MIB provides a set of objects from which other management information can be derived. Provision for future extensions to cover DHCPv4 clients and relay agents, and DHCPv6 extensions are implied by the top-level structure illustrated in section 3.1.1. The examples provided in sections 3.3 through 3.5 are not meant to be comprehensive but are illustrative of the potential uses of the objects defined by this MIB. Hibbs & Waters Expires: August 2004 [Page 3] Internet Draft DHCPv4 Server MIB February 2004 3.1. Relationship to Other MIBs 3.1.1. DHCP MIB Extensions The DHCP MIB extensions will be the "dhcp" branch of the standard MIB-2 tree, as illustrated by the following diagram: +-------+ | MIB-2 | +---+---+ | | +---+---+ | dhcp | +---+---+ | | +--------------+---------------+----------------+ | | | | +-----+-----+ +-----+----+ +-------+-------+ +-----+-----+ | dhcp-v4 | | dhcp-v4 | | dhcp-v4 | |dhcp-v6 MIB| |Server MIB | |Client MIB| |Relay Agent MIB| |Extensions | |(this memo)| | (future) | | (future work) | | (future) | +-----------+ +----------+ +---------------+ +-----------+ The DHCP MIBs share a common branching point but will be independently defined by individual memos. 3.1.2. Host System MIB Extensions The Host System MIB [RFC1123] provides for information, command, and control of the host computer system on which a DHCP server resides. The DHCP Server MIB specifically does not include any objects that may be accessible using the Host System MIB. 3.1.3. DHCP Client MIB Extensions Development of this set of MIB extensions is a natural path given the increasing interest in desktop and client system management. It will share a common branch point in the MIB tree with the other DHCP MIB Extensions, and may use many of the same textual conventions. Hibbs & Waters Expires: August 2004 [Page 4] Internet Draft DHCPv4 Server MIB February 2004 3.1.4. DHCP Relay Agent MIB Extensions If this set of MIB extensions is ever developed, it will share a common branch point in the MIB tree with the other DHCP MIB Extensions, and will use many of the same textual conventions. 3.1.5. DHCPv6 MIB Extensions If this set of MIB extensions is ever developed, it will share a common branch point in the MIB tree with the other DHCP MIB Extensions, and will likely use very different textual conventions as the protocol differs significantly from DHCPv4. 3.2. Textual Conventions Introduced in this MIB One conceptual data type has been introduced in this document. No changes to the SMI or SNMP are necessary to support this convention. 3.2.1. Dhcpv4PhysicalAddress This data type contains the type of hardware address represented by MacAddress, as defined for ARP messages, the length in octets of MacAddress, and the actual layer 1 hardware address. 3.3. BOOTP and DHCP Counter Groups This section describes some of the management information that can be derived from the objects provided in the counter groups. In this context, a "valid" packet is one which has an identifiable message type and has passed all format and validation checks that the DHCP server implements. Not all servers validate received packets in the same way, so there will be differences in the counts reported by different servers. It is appropriate to simply accept the server's notion of what constitutes a valid packet. The total number of valid DHCP packets received by the server is computed as: (dhcpv4CountDiscovers + dhcpv4CountRequests + dhcpv4CountReleases + dhcpv4CountDeclines + dhcpv4CountInforms + dhcpv4CountLeaseQueries) The total number of valid packets (BOOTP and DHCP) received is computed as: Hibbs & Waters Expires: August 2004 [Page 5] Internet Draft DHCPv4 Server MIB February 2004 (total number of valid DHCP packets) + bootpCountRequests) The total number of packets received is computed as: (total number of valid packets) + bootpCountInvalids + dhcpv4CountInvalids Similar to the received computations, the total number of DHCP packets sent by the server is computed as: dhcpv4CountOffers + dhcpv4CountAcks + dhcpv4CountNaks The number of packets (BOOTP and DHCP) sent by the server is computed as: (total number of DHCP packets sent) + (bootpCountReplies) 3.3.1. Discontinuities Hosts for DHCP servers, and the DHCP servers themselves, are generally quite reliable but occasionally counter values may be discontinuous between successive GETs. There are several cases of interest: o Server fails and is restarted, resetting all counters to zero. o Server fails and is restarted, with counters in an unknown state. o Server fails and is restarted, with counters restored to some previously checkpointed value. The first case MAY occur when a server and agent are incapable of restarting to a "last known good" state, and a manager MUST be capable of recognizing this case. There is little a manager can do other than recognize a reset to zero has occurred and continue from the point of restart. The second case is currently the Best Current Practice for SNMP managers. Because of the uncertain state of counters following a server restart, a manager MUST discard data from the outage interval and restart its calculations. The third case SHOULD arise only if agents take periodic snapshots at different intervals than responding to a GET request. While the counts reported in the first GET response following the outage were accurate at some time, they MAY NOT be completely current. If this occurs, the manager MAY have to accept that data has been lost, perhaps discarding accumulated data, and continue. Hibbs & Waters Expires: August 2004 [Page 6] Internet Draft DHCPv4 Server MIB February 2004 3.3.2. Counter Rollover Counter objects increment at different rates. It can be expected that some counter will reach its maximum value and rollover to zero while others are nowhere near their maximum value. When a counter's value at time t2 is less than its value at time t1, the manager SHOULD initially assume that a discontinuity has occurred and perform appropriate data validation to determine if the value has rolled over. If a single rollover has occurred, the value used in calculation SHOULD be: [(maximum value of counter) - (value at time t1)] + (value at time t2) + 1 Managers SHOULD be alert to the possibility of a counter rolling over more than once during the sampling interval. If this is likely to occur (due to very short leases, very large numbers of clients, network topology, and the presence of unreliable clients or intermediate network equipment) a manager SHOULD carefully examine each detected counter rollover to determine if the data can be used or should be discarded. 3.4. Server Configuration Group The server configuration group contains objects that describe the client host configuration information that is held in the server to be offered to requesting clients. Some of the configuration information is static (e.g., a statically configured IPv4 address) and some of the configuration is dynamic (e.g., an assigned DHCP lease). The intent of the server configuration group is to be able to read the server's configuration. The configuration information defines a minimal set of information that most servers should be able to provide. Each row of the dhcpv4ServerSubnetTable lists the subnet address, the subnet mask, and the shared network name that is equivalent to the subnet. Equivalence is defined as more than one subnet being present on the same network segment as some other subnet. The dhcpv4ServerRangeTable lists the start and end IPv4 addresses of the ranges and the subnet of which the range is a member. The dhcpv4ServerRangeInUse object indicates the amount of the range that is currently in use, either through dynamic allocation or being reserved. The range size can be computed as: dhcpv4ServerRangeStartAddress - dhcpv4ServerRangeEndAddress + 1 Hibbs & Waters Expires: August 2004 [Page 7] Internet Draft DHCPv4 Server MIB February 2004 The dhcpv4ServerClientTable provides information about the static and dynamic addresses that the server contains in its configuration. Addresses can be: o Static, in which case they are predefined though the server's configuration. Static addresses may or may not have been previously served by the server; o Dynamic, in which case the server has served the addresses and it is currently in active use by a host; o Expired, in which case the server had previously assigned the address, but the lease time has expired and is retained by the server for possible future use by the same client; o Configuration-reserved, in which case the address is not available for the server to allocate to a client. A configuration-reserved address is one that has been reserved by the administrator. An example of a configuration-reserved address is an address that is assigned to a client, not through DHCP (e.g., statically assigned), and the address is within a DHCP range; and o Server-reserved, in which case the server has taken the address out of use. Examples of server-reserved addresses are those that have been declined (i.e., through a DHCPDECLINE) by a client or those that have responded to an ICMP echo before they were assigned. The protocol used to allocate the address can be determined from the "dhcpv4ServerClientServedProtocol" object. This object indicates whether the address has never been served, or whether BOOTP or DHCP was used to allocate the address. Hibbs & Waters Expires: August 2004 [Page 8] Internet Draft DHCPv4 Server MIB February 2004 4. Definitions DHCP-SERVER-MIB DEFINITIONS ::= BEGIN IMPORTS Counter64, Gauge32, Unsigned32, MODULE-IDENTITY, OBJECT-TYPE, OBJECT-IDENTITY, NOTIFICATION-TYPE, mib-2 FROM SNMPv2-SMI TEXTUAL-CONVENTION, DateAndTime FROM SNMPv2-TC SnmpAdminString FROM SNMP-FRAMEWORK-MIB InetAddressIPv4, InetAddressPrefixLength FROM INET-ADDRESS-MIB MODULE-COMPLIANCE, OBJECT-GROUP, NOTIFICATION-GROUP FROM SNMPv2-CONF; dhcp MODULE-IDENTITY LAST-UPDATED "200402061633Z" ORGANIZATION "IETF DHC Working Group General Discussion: dhcwg@ietf.org Subscribe: http://www1.ietf.org/mailman/listinfo/dhcwg Archive: http://www1.ietf.org/mailman/listinfo/dhcwg Chair: Ralph Droms, rdroms@cisco.com" CONTACT-INFO " Richard Barr Hibbs Postal: 952 Sanchez Street San Francisco, California 94114-3362 USA Tel: +1-(415)-648-3920 Fax: +1-(415)-648-9017 E-mail: rbhibbs@pacbell.net Glenn Waters Postal: Nortel Networks, Inc. 310-875 Carling Avenue Ottawa, Ontario K1S 5P1 Canada Tel: +1-(613)-798-4925 E-mail: gww@NortelNetworks.com" DESCRIPTION "The MIB module for entities implementing the server side of the Bootstrap Protocol (BOOTP) and the Dynamic Host Configuration protocol (DHCP) for Internet Protocol version Hibbs & Waters Expires: August 2004 [Page 9] Internet Draft DHCPv4 Server MIB February 2004 4(IPv4). This MIB does not include support for Dynamic DNS (DDNS) updating nor for the DHCP Failover Protocol. Copyright (C) The Internet Society (2003). This version of this MIB module is part of RFC xxxx; see the RFC itself for full legal notices." -- RFC Editor assigns xxxx and removes this comment REVISION "200402061633Z" -- 6 February 2004 DESCRIPTION "Initial Version, published as RFC xxxx." -- RFC Editor assigns xxxx and removes this comment ::= { mib-2 9999 } -- IANA will make official assignment -- Textual conventions defined by this memo Dhcpv4PhysicalAddress ::= TEXTUAL-CONVENTION DISPLAY-HINT "1d,1d,1x:1x:1x:1x:1x:1x" STATUS current DESCRIPTION "A DHCP-specific encoding of the physical address type and physical address, intended to mirror the representation of physical addresses in DHCP messages. The first octet of this object contains the hardware type from the 'htype' field of the DHCP message, the second octet of this object contains the hardware length from the 'hlen' field, and the remaining octets contain the hardware address from the 'chaddr' field." REFERENCE "RFC 2131" SYNTAX OCTET STRING (SIZE(18)) -- declare top-level MIB objects dhcpv4Server OBJECT-IDENTITY STATUS current DESCRIPTION "DHCPv4 Server MIB objects are defined in this branch." ::= { dhcp 1 } dhcpv4ServerObjects OBJECT-IDENTITY STATUS current DESCRIPTION "DHCP Server MIB server identification objects are all defined in this branch." ::= { dhcpv4Server 1 } dhcpv4ServerSystem OBJECT-IDENTITY STATUS current DESCRIPTION "Group of objects that are related to the overall system." Hibbs & Waters Expires: August 2004 [Page 10] Internet Draft DHCPv4 Server MIB February 2004 ::= { dhcpv4ServerObjects 1 } bootpCounters OBJECT-IDENTITY STATUS current DESCRIPTION "Group of objects that count various BOOTP events." ::= { dhcpv4ServerObjects 2 } dhcpv4Counters OBJECT-IDENTITY STATUS current DESCRIPTION "Group of objects that count various DHCPv4 events." ::= { dhcpv4ServerObjects 3 } dhcpv4ServerConfiguration OBJECT-IDENTITY STATUS current DESCRIPTION "Objects that contain pre-configured and dynamic configuration information." ::= { dhcpv4ServerObjects 6 } dhcpv4ServerNotifyObjects OBJECT-IDENTITY STATUS current DESCRIPTION "Objects that are used only in notifications." ::= { dhcpv4ServerObjects 7 } -- dhcpv4ServerSystemObjects Group dhcpv4ServerSystemDescr OBJECT-TYPE SYNTAX SnmpAdminString (SIZE(0..255)) MAX-ACCESS read-only STATUS current DESCRIPTION "A textual description of the server. This value SHOULD include the full name and version identification of the server." ::= { dhcpv4ServerSystem 1 } dhcpv4ServerSystemObjectID OBJECT-TYPE SYNTAX OBJECT IDENTIFIER MAX-ACCESS read-only STATUS current DESCRIPTION "The vendor's authoritative identification of the network management subsystem contained in this entity. This value is allocated within the SMI enterprise subtree (1.3.6.1.4.1) and provides an easy and unambiguous means for determining what kind of server is being managed. For example, if vendor Ohso Hibbs & Waters Expires: August 2004 [Page 11] Internet Draft DHCPv4 Server MIB February 2004 Soft, Inc. is assigned the subtree 1.3.6.1.4.1.4242, it might assign the identifier 1.3.6.1.4.1.4242.1.1 to its Ursa DHCP Server." ::= { dhcpv4ServerSystem 2 } -- bootpCounterObjects Group bootpCountRequests OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of packets received that contain a Message Type of 1 (BOOTREQUEST) in the first octet and do not contain option number 53 (DHCP Message Type) in the options." REFERENCE "RFC-2131." ::= { bootpCounters 1 } bootpCountInvalids OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of packets received that do not contain a Message Type of 1 (BOOTREQUEST) in the first octet or are not valid BOOTP packets (e.g., too short, invalid field in packet header)." ::= { bootpCounters 2 } bootpCountReplies OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of packets sent that contain a Message Type of 2 (BOOTREPLY) in the first octet and do not contain option number 53 (DHCP Message Type) in the options." REFERENCE "RFC-2131." ::= { bootpCounters 3 } bootpCountDroppedUnknownClients OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION Hibbs & Waters Expires: August 2004 [Page 12] Internet Draft DHCPv4 Server MIB February 2004 "The number of BOOTP packets dropped due to the server not recognizing or not providing service to the hardware address received in the incoming packet." ::= { bootpCounters 4 } bootpCountDroppedNotServingSubnet OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of BOOTP packets dropped due to the server not being configured or not otherwise able to serve addresses on the subnet from which this message was received." ::= { bootpCounters 5 } -- DHCP Counters Group dhcpv4CountDiscovers OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCPDISCOVER (option 53 with value 1) packets received." REFERENCE "RFC2131; RFC2132, section 9.6." ::= { dhcpv4Counters 1 } dhcpv4CountOffers OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCPOFFER (option 53 with value 2) packets sent." REFERENCE "RFC2131; RFC2132, section 9.6." ::= { dhcpv4Counters 2 } dhcpv4CountRequests OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCPREQUEST (option 53 with value 3) packets received." REFERENCE "RFC2131; RFC2132, section 9.6." ::= { dhcpv4Counters 3} Hibbs & Waters Expires: August 2004 [Page 13] Internet Draft DHCPv4 Server MIB February 2004 dhcpv4CountDeclines OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCPDECLINE (option 53 with value 4) packets received." REFERENCE "RFC2131; RFC2132, section 9.6." ::= { dhcpv4Counters 4 } dhcpv4CountAcks OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCPACK (option 53 with value 5) packets sent." REFERENCE "RFC2131; RFC2132, section 9.6." ::= { dhcpv4Counters 5 } dhcpv4CountNaks OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCPNACK (option 53 with value 6) packets sent." REFERENCE "RFC2131; RFC2132, section 9.6." ::= { dhcpv4Counters 6 } dhcpv4CountReleases OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCPRELEASE (option 53 with value 7) packets received." REFERENCE "RFC2131; RFC2132, section 9.6." ::= { dhcpv4Counters 7 } dhcpv4CountInforms OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION Hibbs & Waters Expires: August 2004 [Page 14] Internet Draft DHCPv4 Server MIB February 2004 "The number of DHCPINFORM (option 53 with value 8) packets received." REFERENCE "RFC2131; RFC2132, section 9.6." ::= { dhcpv4Counters 8 } dhcpv4CountForcedRenews OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCPFORCERENEW (option 53 with value 9) packets sent." REFERENCE " RFC 3203, DHCP reconfigure extension." ::= { dhcpv4Counters 9 } dhcpv4CountInvalids OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCP packets received whose DHCP message type (i.e., option number 53) is not understood or handled by the server." ::= { dhcpv4Counters 10 } dhcpv4CountDroppedUnknownClient OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCP packets dropped due to the server not recognizing or not providing service to the client-id and/or hardware address received in the incoming packet." ::= { dhcpv4Counters 11 } dhcpv4CountDroppedNotServingSubnet OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCP packets dropped due to the server not being configured or not otherwise able to serve addresses on the subnet from which this message was received." ::= { dhcpv4Counters 12 } -- DHCP Server Configuration Hibbs & Waters Expires: August 2004 [Page 15] Internet Draft DHCPv4 Server MIB February 2004 -- dhcpv4ServerSharedNetObjects Group dhcpv4ServerSharedNetTable OBJECT-TYPE SYNTAX SEQUENCE OF Dhcpv4ServerSharedNetEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A list of shared networks that are configured in the server. A shared network is the logical aggregation of one or more subnets that share a common network segment (e.g., multi- tapped coaxial cable, wiring hub, or switch). This table is present ONLY for those servers that organize the ranges of addresses available for assignment where a higher-level grouping (i.e., the 'shared' network) exists above ranges and subnets." ::= { dhcpv4ServerConfiguration 1 } dhcpv4ServerSharedNetEntry OBJECT-TYPE SYNTAX Dhcpv4ServerSharedNetEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A logical row in the dhcpv4ServerSharedNetTable." INDEX { dhcpv4ServerSharedNetName } ::= { dhcpv4ServerSharedNetTable 1} Dhcpv4ServerSharedNetEntry ::= SEQUENCE { dhcpv4ServerSharedNetName SnmpAdminString, dhcpv4ServerSharedNetFreeAddrLowThreshold Unsigned32, dhcpv4ServerSharedNetFreeAddrHighThreshold Unsigned32, dhcpv4ServerSharedNetFreeAddresses Unsigned32, dhcpv4ServerSharedNetReservedAddresses Unsigned32, dhcpv4ServerSharedNetTotalAddresses Unsigned32 } dhcpv4ServerSharedNetName OBJECT-TYPE SYNTAX SnmpAdminString (SIZE(1..100)) MAX-ACCESS not-accessible STATUS current DESCRIPTION "The name of the shared network, which uniquely identifies an entry in the dhcpv4ServerSharedNetTable." ::= { dhcpv4ServerSharedNetEntry 1 } dhcpv4ServerSharedNetFreeAddrLowThreshold OBJECT-TYPE SYNTAX Unsigned32 MAX-ACCESS accessible-for-notify STATUS current Hibbs & Waters Expires: August 2004 [Page 16] Internet Draft DHCPv4 Server MIB February 2004 DESCRIPTION "The low threshold for available free addresses in this shared network. If the value for available free addresses in this shared network becomes equal to or less than this value, a dhcpv4ServerFreeAddressLow event is generated for this shared network. No more dhcpv4ServerFreeAddressLow events will be generated for this subnet during this execution of the DHCP server until the value for available free addresses has exceeded the value of dhcpv4ServerSharedNetFreeAddrHighThreshold." ::= { dhcpv4ServerSharedNetEntry 2 } dhcpv4ServerSharedNetFreeAddrHighThreshold OBJECT-TYPE SYNTAX Unsigned32 MAX-ACCESS accessible-for-notify STATUS current DESCRIPTION "The high threshold for available free addresses in this shared network. If a dhcpv4ServerFreeAddressLow event was generated for this subnet, and the value for available free addresses has exceeded the value of dhcpv4ServerSubnetFreeAddrHighThreshold, then a dhcpv4ServerFreeAddressHigh event will be generated. No more dhcpv4ServerFreeAddressHigh events will be generated for this subnet during this execution of the DHCP server until the value for available free addresses becomes equal to or less than the value of dhcpv4ServerSubnetFreeAddrLowThreshold." ::= { dhcpv4ServerSharedNetEntry 3 } dhcpv4ServerSharedNetFreeAddresses OBJECT-TYPE SYNTAX Unsigned32 MAX-ACCESS accessible-for-notify STATUS current DESCRIPTION "The number of IPv4 addresses which are available within this shared network. If the server does not count free addresses by shared network segment, this value will be zero." ::= { dhcpv4ServerSharedNetEntry 4 } dhcpv4ServerSharedNetReservedAddresses OBJECT-TYPE SYNTAX Unsigned32 MAX-ACCESS accessible-for-notify STATUS current DESCRIPTION "The number of IPv4 addresses which are reserved (not available for assignment) within this shared network. If the server does not count reserved addresses by shared network segment, this value will be zero." ::= { dhcpv4ServerSharedNetEntry 5 } Hibbs & Waters Expires: August 2004 [Page 17] Internet Draft DHCPv4 Server MIB February 2004 dhcpv4ServerSharedNetTotalAddresses OBJECT-TYPE SYNTAX Unsigned32 MAX-ACCESS accessible-for-notify STATUS current DESCRIPTION "The number of IPv4 addresses which are available within this shared network. If the server does not count total addresses by shared network segment, this value will be zero." ::= { dhcpv4ServerSharedNetEntry 6 } -- dhcpv4ServerSubnetObjects Group dhcpv4ServerSubnetTable OBJECT-TYPE SYNTAX SEQUENCE OF Dhcpv4ServerSubnetEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A list of subnets that are configured in this server." ::= { dhcpv4ServerConfiguration 2 } dhcpv4ServerSubnetEntry OBJECT-TYPE SYNTAX Dhcpv4ServerSubnetEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A logical row in the dhcpv4ServerSubnetTable." INDEX { dhcpv4ServerSubnetAddress } ::= { dhcpv4ServerSubnetTable 1 } Dhcpv4ServerSubnetEntry ::= SEQUENCE { dhcpv4ServerSubnetAddress InetAddressIPv4, dhcpv4ServerSubnetMask InetAddressPrefixLength, dhcpv4ServerSubnetSharedNetworkName SnmpAdminString, dhcpv4ServerSubnetFreeAddrLowThreshold Unsigned32, dhcpv4ServerSubnetFreeAddrHighThreshold Unsigned32, dhcpv4ServerSubnetFreeAddresses Unsigned32 } dhcpv4ServerSubnetAddress OBJECT-TYPE SYNTAX InetAddressIPv4 MAX-ACCESS not-accessible STATUS current DESCRIPTION "The IPv4 address of the subnet entry in the dhcpv4ServerSubnetTable." ::= { dhcpv4ServerSubnetEntry 1 } Hibbs & Waters Expires: August 2004 [Page 18] Internet Draft DHCPv4 Server MIB February 2004 dhcpv4ServerSubnetMask OBJECT-TYPE SYNTAX InetAddressPrefixLength MAX-ACCESS read-only STATUS current DESCRIPTION "The subnet mask of the subnet. This MUST be the same as the value of DHCP option 1 offered to clients on this subnet." ::= { dhcpv4ServerSubnetEntry 2 } dhcpv4ServerSubnetSharedNetworkName OBJECT-TYPE SYNTAX SnmpAdminString (SIZE(1..100)) MAX-ACCESS read-only STATUS current DESCRIPTION "The shared subnet name (used as an index into the server shared subnet table) to which this subnet belongs. This value will be null for servers that do not organize or describe networks in this manner." ::= { dhcpv4ServerSubnetEntry 3 } dhcpv4ServerSubnetFreeAddrLowThreshold OBJECT-TYPE SYNTAX Unsigned32 MAX-ACCESS accessible-for-notify STATUS current DESCRIPTION "The low threshold for available free addresses in this subnet. If the value for available free addresses in this subnet becomes equal to or less than this value, a dhcpv4ServerSubnetFreeAddrLowThreshold event will be generated for this shared network. No more dhcpv4ServerSubnetFreeAddrLowThreshold events will be generated for this subnet during this execution of the DHCP server until the value for available free addresses has exceeded the value of dhcpv4ServerSubnetFreeAddrHighThreshold." ::= { dhcpv4ServerSubnetEntry 4 } dhcpv4ServerSubnetFreeAddrHighThreshold OBJECT-TYPE SYNTAX Unsigned32 MAX-ACCESS accessible-for-notify STATUS current DESCRIPTION "The high threshold for available free addresses in this subnet. If a dhcpv4ServerSubnetFreeAddrLowThreshold event has been generated for this subnet, and the value for available free addresses has exceeded the value of dhcpv4ServerSubnetFreeAddrHighThreshold, then a dhcpv4ServerFreeAddressHigh event will be generated. No more dhcpv4ServerFreeAddressHigh events will be generated for this Hibbs & Waters Expires: August 2004 [Page 19] Internet Draft DHCPv4 Server MIB February 2004 subnet during this execution of the DHCP server until the value for available free addresses becomes equal to or less than the value of dhcpv4ServerSubnetFreeAddrLowThreshold." ::= { dhcpv4ServerSubnetEntry 5 } dhcpv4ServerSubnetFreeAddresses OBJECT-TYPE SYNTAX Unsigned32 MAX-ACCESS accessible-for-notify STATUS current DESCRIPTION "The number of free IPv4 addresses which are available in this subnet." ::= { dhcpv4ServerSubnetEntry 6 } -- dhcpv4ServerRangeObjects Group dhcpv4ServerRangeTable OBJECT-TYPE SYNTAX SEQUENCE OF Dhcpv4ServerRangeEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A list of ranges that are configured on this server." ::= { dhcpv4ServerConfiguration 3 } dhcpv4ServerRangeEntry OBJECT-TYPE SYNTAX Dhcpv4ServerRangeEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A logical row in the dhcpv4ServerRangeTable." INDEX { dhcpv4ServerRangeStartAddress, dhcpv4ServerRangeEndAddress } ::= { dhcpv4ServerRangeTable 1 } Dhcpv4ServerRangeEntry ::= SEQUENCE { dhcpv4ServerRangeStartAddress InetAddressIPv4, dhcpv4ServerRangeEndAddress InetAddressIPv4, dhcpv4ServerRangeSubnetMask InetAddressPrefixLength, dhcpv4ServerRangeInUse Gauge32, dhcpv4ServerRangeOutstandingOffers Gauge32 } dhcpv4ServerRangeStartAddress OBJECT-TYPE SYNTAX InetAddressIPv4 MAX-ACCESS not-accessible STATUS current DESCRIPTION Hibbs & Waters Expires: August 2004 [Page 20] Internet Draft DHCPv4 Server MIB February 2004 "The IPv4 address of the first address in the range. The value of dhcpv4ServerRangeStartAddress MUST be less than or equal to the value of dhcpv4ServerRangeEndAddress." ::= { dhcpv4ServerRangeEntry 1 } dhcpv4ServerRangeEndAddress OBJECT-TYPE SYNTAX InetAddressIPv4 MAX-ACCESS not-accessible STATUS current DESCRIPTION "The IPv4 address of the last address in the range. The value of dhcpv4ServerRangeEndAddress MUST be greater than or equal to the value of dhcpv4ServerRangeStartAddress." ::= { dhcpv4ServerRangeEntry 2 } dhcpv4ServerRangeSubnetMask OBJECT-TYPE SYNTAX InetAddressPrefixLength MAX-ACCESS read-only STATUS current DESCRIPTION "The subnet address mask for this range." ::= { dhcpv4ServerRangeEntry 3 } dhcpv4ServerRangeInUse OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of addresses in this range that are currently in use. This number includes those addresses whose lease has not expired and addresses which have been reserved (either by the server or through configuration)." ::= { dhcpv4ServerRangeEntry 4 } dhcpv4ServerRangeOutstandingOffers OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of outstanding DHCPOFFER messages for this range is reported with this value. An offer is outstanding if the server has sent a DHCPOFFER message to a client, but has not yet received a DHCPREQUEST message from the client nor has the server-specific timeout (limiting the time in which a client can respond to the offer message) for the offer message expired." ::= { dhcpv4ServerRangeEntry 5 } -- dhcpv4ServerClientObjects Group Hibbs & Waters Expires: August 2004 [Page 21] Internet Draft DHCPv4 Server MIB February 2004 dhcpv4ServerClientTable OBJECT-TYPE SYNTAX SEQUENCE OF Dhcpv4ServerClientEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "An optional list of addresses that are known by this server. The list MUST contain addresses that have not expired. The list MUST NOT contain addresses that have never been assigned by the server UNLESS the lease is pre-configured in the server (e.g., a static lease for a host). Expired leases MAY appear during the time they are 'remembered' by the server for subsequent assignment to the same host." ::= { dhcpv4ServerConfiguration 4 } dhcpv4ServerClientEntry OBJECT-TYPE SYNTAX Dhcpv4ServerClientEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A logical row in the dhcpv4ServerClientTable." INDEX { dhcpv4ServerClient } ::= { dhcpv4ServerClientTable 1 } Dhcpv4ServerClientEntry ::= SEQUENCE { dhcpv4ServerClient InetAddressIPv4, dhcpv4ServerClientSubnetMask InetAddressPrefixLength, dhcpv4ServerClientRange InetAddressIPv4, dhcpv4ServerClientLeaseType INTEGER, dhcpv4ServerClientTimeRemaining Unsigned32, dhcpv4ServerClientAllowedProtocol INTEGER, dhcpv4ServerClientServedProtocol INTEGER, dhcpv4ServerClientPhysicalAddress Dhcpv4PhysicalAddress, dhcpv4ServerClientClientId OCTET STRING, dhcpv4ServerClientHostName SnmpAdminString, dhcpv4ServerClientDomainName SnmpAdminString } dhcpv4ServerClient OBJECT-TYPE SYNTAX InetAddressIPv4 MAX-ACCESS not-accessible STATUS current DESCRIPTION "The IPv4 address of this entry in the dhcpv4ServerClientTable." ::= { dhcpv4ServerClientEntry 1 } dhcpv4ServerClientSubnetMask OBJECT-TYPE Hibbs & Waters Expires: August 2004 [Page 22] Internet Draft DHCPv4 Server MIB February 2004 SYNTAX InetAddressPrefixLength MAX-ACCESS read-only STATUS current DESCRIPTION "The subnet mask (DHCP option 1) provided to the client offered this address. The subnet, resulting from logically ANDing the subnet mask with the entry's IPv4 address, MUST be configured on this server and appear as a row in the dhcpSubnetTable." ::= { dhcpv4ServerClientEntry 2 } dhcpv4ServerClientRange OBJECT-TYPE SYNTAX InetAddressIPv4 MAX-ACCESS read-only STATUS current DESCRIPTION "The starting IPv4 address (dhcpv4ServerRangeStartAddress object) of the range to which this address belongs. If the address does not fall into one of the configured ranges (e.g., a statically configured address on a subnet) the range MAY be 0.0.0.0." ::= { dhcpv4ServerClientEntry 3 } dhcpv4ServerClientLeaseType OBJECT-TYPE SYNTAX INTEGER { static(1), dynamic(2), expired(3), configurationReserved(4), serverReserved(5) } MAX-ACCESS read-only STATUS current DESCRIPTION "The type of this address. Types are: (1) Static addresses defined by the server configuration. (2) Dynamic addresses defined by the server configuration AND actually assigned by the server. (3) Expired dynamic addresses, previously assigned by the server, and 'remembered' for subsequent assignment to the same host. (4) Addresses reserved (i.e., not assignable) by the server configuration. (5) Addresses previously assigned by the server, but temporarily or permanently removed from assignable state for some reason, e.g., the server received an ICMP ECHOREPLY for the IPv4 address or a DHCPDECLINE message has been received for the IPv4 address." ::= { dhcpv4ServerClientEntry 4 } Hibbs & Waters Expires: August 2004 [Page 23] Internet Draft DHCPv4 Server MIB February 2004 dhcpv4ServerClientTimeRemaining OBJECT-TYPE SYNTAX Unsigned32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of seconds until the lease expires. A value of 4294967295 (i.e., 0xFFFFFFFF) SHOULD be used for leases that have a lease time which is 'infinite' and for BOOTP leases." ::= { dhcpv4ServerClientEntry 5 } dhcpv4ServerClientAllowedProtocol OBJECT-TYPE SYNTAX INTEGER { none(1), bootp(2), dhcp(3), bootpOrDhcp(4) } MAX-ACCESS read-only STATUS current DESCRIPTION "The type of protocol that is allowed to be used to serve this address. A type of none (1) indicates that the address is not available to be served (e.g., a reserved address). Type (2) is reserved for BOOTP only devices, while type (3) is reserved for DHCP only devices. A type of bootp-or-dhcp (4) can be offered to any type of client." ::= { dhcpv4ServerClientEntry 6 } dhcpv4ServerClientServedProtocol OBJECT-TYPE SYNTAX INTEGER { none(1), bootp(2), dhcp(3) } MAX-ACCESS read-only STATUS current DESCRIPTION "The type of protocol that was used when this address was assigned. This object will have the value of none (1) if the address has not been served." ::= { dhcpv4ServerClientEntry 7 } dhcpv4ServerClientPhysicalAddress OBJECT-TYPE SYNTAX Dhcpv4PhysicalAddress MAX-ACCESS read-only STATUS current DESCRIPTION "The hardware type and hardware address of the client that has been assigned this lease. The first octet of this object contains the hardware type from the 'htype' field of the BOOTP Hibbs & Waters Expires: August 2004 [Page 24] Internet Draft DHCPv4 Server MIB February 2004 packet and the remaining octets contain the hardware address from the 'chaddr' field of the BOOTP packet. This object MAY be empty if the address has not been previously served." ::= { dhcpv4ServerClientEntry 8 } dhcpv4ServerClientClientId OBJECT-TYPE SYNTAX OCTET STRING (SIZE(0..255)) MAX-ACCESS read-only STATUS current DESCRIPTION "The client-id of the client that has been assigned this lease. The client-id is the value specified in option 61 (client-id option) when the lease was assigned. This object MAY be empty if the lease has not been previously assigned or if the client-id option was not specified when the address was assigned." ::= { dhcpv4ServerClientEntry 9 } dhcpv4ServerClientHostName OBJECT-TYPE SYNTAX SnmpAdminString (SIZE(1..255)) MAX-ACCESS read-only STATUS current DESCRIPTION "The host name (DHCP option 12) the client is configured to use, or if no host name was configured then the host name that the client supplied when requesting an address. While this object has a maximum size of 255 octets, a Fully-Qualified Domain Name (FQDN) consisting of a Host Name part and a Domain Name part is currently limited to 255 octets. Therefore, the sum of the string lengths for this object and the dhcpv4ServerClientDomainName MUST be, in practice, less than 256 octets." ::= { dhcpv4ServerClientEntry 10 } dhcpv4ServerClientDomainName OBJECT-TYPE SYNTAX SnmpAdminString (SIZE(1..255)) MAX-ACCESS read-only STATUS current DESCRIPTION "The domain name (DHCP option 15) assigned to the client. While this object has a maximum size of 255 octets, a Fully- Qualified Domain Name (FQDN) consisting of a Host Name part and a Domain Name part is currently limited to 255 octets, less the separator ('.') character. Therefore, the sum of the string lengths for this object and the dhcpv4ServerClientHostName MUST be, in practice, less than 256 octets." ::= { dhcpv4ServerClientEntry 11 } Hibbs & Waters Expires: August 2004 [Page 25] Internet Draft DHCPv4 Server MIB February 2004 -- dhcpv4ServerNotifyObjects Group dhcpv4ServerNotifyDuplicateIpAddr OBJECT-TYPE SYNTAX InetAddressIPv4 MAX-ACCESS accessible-for-notify STATUS current DESCRIPTION "The IPv4 address found to be a duplicate. Duplicates are detected by servers, which issue an ICMP ECHOREQUEST prior to offering an IPv4 address lease, or by a client issuing a gratuitous ARP message and reported through a DHCPDECLINE message." ::= { dhcpv4ServerNotifyObjects 1 } dhcpv4ServerNotifyDuplicateMac OBJECT-TYPE SYNTAX Dhcpv4PhysicalAddress MAX-ACCESS accessible-for-notify STATUS current DESCRIPTION "The offending MAC address which caused a duplicate IPv4 address to be detected, if captured by the server, else 00-00- 00-00-00-00." ::= { dhcpv4ServerNotifyObjects 2 } dhcpv4ServerNotifyClientOrServerDetected OBJECT-TYPE SYNTAX INTEGER { client(1), server(2) } MAX-ACCESS accessible-for-notify STATUS current DESCRIPTION "Duplicate IPv4 addresses can be detected either by a server, using an ICMP ECHO message, or by a client using ARP. This object is set by the server to (1) if the client used DHCPDECLINE to mark the offered address as in-use, or to (2) if the server discovered the address in use by some client before offering it." ::= { dhcpv4ServerNotifyObjects 3 } dhcpv4ServerNotifyServerStart OBJECT-TYPE SYNTAX DateAndTime MAX-ACCESS accessible-for-notify STATUS current DESCRIPTION "The date and time when the server began operation." ::= { dhcpv4ServerNotifyObjects 4 } dhcpv4ServerNotifyServerStop OBJECT-TYPE SYNTAX DateAndTime Hibbs & Waters Expires: August 2004 [Page 26] Internet Draft DHCPv4 Server MIB February 2004 MAX-ACCESS accessible-for-notify STATUS current DESCRIPTION "The date and time when the server ceased operation." ::= { dhcpv4ServerNotifyObjects 5 } -- Notifications dhcpv4ServerNotificationPrefix OBJECT IDENTIFIER ::= { dhcpv4Server 2 } dhcpv4ServerNotifications OBJECT IDENTIFIER ::= { dhcpv4ServerNotificationPrefix 0 } dhcpv4ServerFreeAddressLow NOTIFICATION-TYPE OBJECTS { dhcpv4ServerSharedNetFreeAddrLowThreshold, dhcpv4ServerSharedNetFreeAddresses } STATUS current DESCRIPTION "This notification signifies that the number of available IPv4 addresses for a particular shared network has fallen below the value of dhcpv4ServerSharedNetFreeAddrLowThreshold for that shared network." ::= { dhcpv4ServerNotifications 1 } dhcpv4ServerFreeAddressHigh NOTIFICATION-TYPE OBJECTS { dhcpv4ServerSharedNetFreeAddrHighThreshold, dhcpv4ServerSharedNetFreeAddresses } STATUS current DESCRIPTION "This notification signifies that the number of available IPv4 addresses for a particular shared network has risen above the value of dhcpv4ServerSharedNetFreeAddrHighThreshold for that shared network." ::= { dhcpv4ServerNotifications 2 } dhcpv4ServerStartTime NOTIFICATION-TYPE OBJECTS { dhcpv4ServerNotifyServerStart } STATUS current DESCRIPTION "This notification signifies that the server of the specified type has started on the host from which this notification has been sent." ::= { dhcpv4ServerNotifications 3 } Hibbs & Waters Expires: August 2004 [Page 27] Internet Draft DHCPv4 Server MIB February 2004 dhcpv4ServerStopTime NOTIFICATION-TYPE OBJECTS { dhcpv4ServerNotifyServerStop } STATUS current DESCRIPTION "This notification signifies that the server of the specified type has stopped normally on the host from which this notification has been sent." ::= { dhcpv4ServerNotifications 4 } dhcpv4ServerDuplicateAddress NOTIFICATION-TYPE OBJECTS { dhcpv4ServerNotifyDuplicateIpAddr, dhcpv4ServerNotifyDuplicateMac, dhcpv4ServerNotifyClientOrServerDetected } STATUS current DESCRIPTION "This notification signifies that a duplicate IPv4 address has been detected. The DHCP server can detect this condition through the ping-before-offer mechanism. Alternatively, the client may have sent a DHCPDECLINE back to the server; this is assumed to be the result of the client detecting that the address was in use. In either case, the DHCP server marks the IPv4 address as unavailable for leasing to clients. The dhcpv4ServerNotifyClientOrServerDetected object indicates whether the client or server detected this condition." ::= { dhcpv4ServerNotifications 5 } -- Conformance dhcpv4ServerConformance OBJECT-IDENTITY STATUS current DESCRIPTION "DHCP server conformance objects are all defined in this branch." ::= { dhcpv4Server 3 } dhcpv4ServerCompliances OBJECT IDENTIFIER ::= { dhcpv4ServerConformance 1 } dhcpv4ServerGroups OBJECT IDENTIFIER ::= { dhcpv4ServerConformance 2 } -- Compliance groups dhcpv4ServerCompliance MODULE-COMPLIANCE STATUS current Hibbs & Waters Expires: August 2004 [Page 28] Internet Draft DHCPv4 Server MIB February 2004 DESCRIPTION "This group describes the requirements for conformance to the DHCP Server MIB. A DHCPv4 server implementation is only REQUIRED to support IPv4 addresses. In particular, this comment applies to the following objects with MAX-ACCESS not- accessible: dhcpv4ServerSubnet dhcpv4ServerRangeStart dhcpv4ServerRangeEnd dhcpv4ServerClient." MODULE -- this module MANDATORY-GROUPS { dhcpv4ServerSystemObjects, bootpCounterObjects, dhcpv4CounterObjects, dhcpv4ServerSharedNetObjects, dhcpv4ServerSubnetObjects, dhcpv4ServerRangeObjects, dhcpv4ServerClientObjects, dhcpv4ServerNotifyObjectsGroup, dhcpv4ServerNotificationsGroup } ::= { dhcpv4ServerCompliances 1 } -- Object groups dhcpv4ServerSystemObjects OBJECT-GROUP OBJECTS { dhcpv4ServerSystemDescr, dhcpv4ServerSystemObjectID } STATUS current DESCRIPTION "Objects belonging to the dhcpv4ServerSystemObjects group." ::= { dhcpv4ServerGroups 1 } bootpCounterObjects OBJECT-GROUP OBJECTS { bootpCountRequests, bootpCountInvalids, bootpCountReplies, bootpCountDroppedUnknownClients, bootpCountDroppedNotServingSubnet } STATUS current DESCRIPTION "Objects belonging to the bootpBounterObjects group." ::= { dhcpv4ServerGroups 2 } Hibbs & Waters Expires: August 2004 [Page 29] Internet Draft DHCPv4 Server MIB February 2004 dhcpv4CounterObjects OBJECT-GROUP OBJECTS { dhcpv4CountDiscovers, dhcpv4CountOffers, dhcpv4CountRequests, dhcpv4CountDeclines, dhcpv4CountAcks, dhcpv4CountNaks, dhcpv4CountReleases, dhcpv4CountInforms, dhcpv4CountForcedRenews, dhcpv4CountInvalids, dhcpv4CountDroppedUnknownClient, dhcpv4CountDroppedNotServingSubnet } STATUS current DESCRIPTION "Objects belonging to the dhcpv4CounterObjects group." ::= { dhcpv4ServerGroups 3 } dhcpv4ServerSharedNetObjects OBJECT-GROUP OBJECTS { dhcpv4ServerSharedNetFreeAddrLowThreshold, dhcpv4ServerSharedNetFreeAddrHighThreshold, dhcpv4ServerSharedNetFreeAddresses, dhcpv4ServerSharedNetReservedAddresses, dhcpv4ServerSharedNetTotalAddresses } STATUS current DESCRIPTION "Objects belonging to the dhcpv4ServerSharedNetObjects group." ::= { dhcpv4ServerGroups 4 } dhcpv4ServerSubnetObjects OBJECT-GROUP OBJECTS { dhcpv4ServerSubnetMask, dhcpv4ServerSubnetSharedNetworkName, dhcpv4ServerSubnetFreeAddrLowThreshold, dhcpv4ServerSubnetFreeAddrHighThreshold, dhcpv4ServerSubnetFreeAddresses } STATUS current DESCRIPTION "Objects belonging to the dhcpv4ServerSubnetObjects group." ::= { dhcpv4ServerGroups 5 } dhcpv4ServerRangeObjects OBJECT-GROUP OBJECTS { dhcpv4ServerRangeSubnetMask, dhcpv4ServerRangeInUse, Hibbs & Waters Expires: August 2004 [Page 30] Internet Draft DHCPv4 Server MIB February 2004 dhcpv4ServerRangeOutstandingOffers } STATUS current DESCRIPTION "Objects belonging to the dhcpv4ServerRangeObjects group." ::= { dhcpv4ServerGroups 6 } dhcpv4ServerClientObjects OBJECT-GROUP OBJECTS { dhcpv4ServerClientSubnetMask, dhcpv4ServerClientRange, dhcpv4ServerClientLeaseType, dhcpv4ServerClientTimeRemaining, dhcpv4ServerClientAllowedProtocol, dhcpv4ServerClientServedProtocol, dhcpv4ServerClientPhysicalAddress, dhcpv4ServerClientClientId, dhcpv4ServerClientHostName, dhcpv4ServerClientDomainName } STATUS current DESCRIPTION "Objects belonging to the dhcpv4ServerClientObjects group." ::= { dhcpv4ServerGroups 7 } dhcpv4ServerNotifyObjectsGroup OBJECT-GROUP OBJECTS { dhcpv4ServerNotifyDuplicateIpAddr, dhcpv4ServerNotifyDuplicateMac, dhcpv4ServerNotifyClientOrServerDetected, dhcpv4ServerNotifyServerStart, dhcpv4ServerNotifyServerStop } STATUS current DESCRIPTION "Objects belonging to the dhcpv4ServerNotifyObjects group." ::= { dhcpv4ServerGroups 8 } dhcpv4ServerNotificationsGroup NOTIFICATION-GROUP NOTIFICATIONS { dhcpv4ServerFreeAddressLow, dhcpv4ServerFreeAddressHigh, dhcpv4ServerStartTime, dhcpv4ServerStopTime, dhcpv4ServerDuplicateAddress } STATUS current DESCRIPTION "Notifications belonging to the dhcpv4ServerNotifications group." Hibbs & Waters Expires: August 2004 [Page 31] Internet Draft DHCPv4 Server MIB February 2004 ::= { dhcpv4ServerGroups 9 } END Hibbs & Waters Expires: August 2004 [Page 32] Internet Draft DHCPv4 Server MIB February 2004 5. Intellectual Property The IETF takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. Copies of claims of rights made available for publication and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF Secretariat. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director. 6. Acknowledgements This document is the result of work undertaken by the DHCP working group. The editors would like to particularly acknowledge the development team from Carnegie-Mellon University whose work creating a private MIB for their DHCP server inspired the development of this proposal. In particular, many thanks to Ryan Troll who provided a great deal of useful feedback during the initial development of this MIB, and to Rich Woundy for his excellent suggestions that helped bring the work to closure. 7. IANA Considerations IANA MUST fill in the value of the RFC number when it is assigned to this memo. It is represented as "xxxx" in the DESCRIPTION section of MODULE-IDENTITY. One specific value for a MIB object requires completion before this memo can advance to RFC status. It is: o OID value for "dhcp" -- see MODULE-IDENTITY Hibbs & Waters Expires: August 2004 [Page 33] Internet Draft DHCPv4 Server MIB February 2004 8. Security Considerations There are no management objects defined in this MIB that have a MAX- ACCESS clause of read-write or read-create. Such objects may be considered sensitive or vulnerable in some environments. The support for SET operations in a non-secure environment without proper protection can have a negative effect on network operations. Therefore, if this MIB is implemented correctly, there is no risk that an intruder can alter or create any management objects of this MIB via direct SNMP SET operations. Some of the readable objects in this MIB module (i.e., objects with a MAX-ACCESS other than not-accessible) may be considered sensitive or vulnerable in some network environments. It is thus important to control even GET and/or NOTIFY access to these objects and possibly to even encrypt the values of these objects when sending them over the network via SNMP. These are the tables and objects and their sensitivity/vulnerability: o dhcpv4ServerRangeTable o dhcpv4ServerClientTable These two objects, in conjunction, provide an observer with a current view of the available and assigned addresses allocated by this server. Such knowledge can be used to manually configure a host computer with a valid IPv4 address for the network managed by the DHCP server. This could be part of either a Theft of Service scheme or a Denial of Service attack wherein rogue (pseudo-)hosts simply claim and defend IPv4 addresses either to subvert accounting for their use or to disrupt the network for legitimate hosts. It is thus important to control even GET access to these objects and possibly to even encrypt the values of these objects when sending them over the network via SNMP. Not all versions of SNMP provide features for such a secure environment. SNMP versions prior to SNMPv3 did not include adequate security. Even if the network itself is secure (for example by using IPSec), even then, there is no control as to who on the secure network is allowed to access and GET/SET (read/change/create/delete) the objects in this MIB. It is RECOMMENDED that the implementers consider the security features as provided by the SNMPv3 framework (see [RFC3410], section 8), including full support for the SNMPv3 cryptographic mechanisms (for authentication and privacy). Further, deployment of SNMP versions prior to SNMPv3 is NOT RECOMMENDED. Instead, it is RECOMMENDED to deploy SNMPv3 and to Hibbs & Waters Expires: August 2004 [Page 34] Internet Draft DHCPv4 Server MIB February 2004 enable cryptographic security. It is then a customer/operator responsibility to ensure that the SNMP entity giving access to an instance of this MIB module is properly configured to give access to the objects only to those principals (users) that have legitimate rights to indeed GET or SET (change/create/delete) them. Denial of Service attacks on a DHCP server are conceivable by flooding the SNMP (sub-)agent with requests, tying up host system and server resources processing SNMP messages. The authors know of no way to wholly prevent such attacks, but have attempted to construct relatively simple tables to minimize the work required to respond to messages. 9. References One normative reference is currently an Internet-Draft, nearly ready for Working Group Last Call. This reference MUST be updated when the draft advances to RFC status. 9.1. Normative References [RFC2131] Droms, R., "Dynamic Host Configuration Protocol," RFC 2131, March 1997. [RFC2132] Alexander, S. and Droms, R., "DHCP Options and BOOTP Vendor Extensions," RFC 2132, March 1997. [RFC2578] Case, J., McCloghrie, K., Perkins, D., Rose, M., Schoenwaelder, J., and S. Waldbusser, "Structure of Management Information for Version 2 of the Simple Network Management Protocol (SNMPv2)," RFC 2578, April 1999. [RFC2579] Case, J., McCloghrie, K., Rose, M., Schoenwaelder, J., and S. Waldbusser, "Textual Conventions for Version 2 of the Simple Network Management Protocol (SNMPv2)," RFC 2579, April 1999. [RFC2580] Case, J., McCloghrie, K., Rose, M., Schoenwaelder, J., and S. Waldbusser, "Conformance Statements for Version 2 of the Simple Network Management Protocol (SNMPv2)," RFC 2580, April 1999. [RFC3203], Yves T'Joens and Christian Hublet, Peter De Schrijver, "The DHCP Reconfigure Extension," July 2001 9.2. Informative References [RFC1123] R. Braden, "Requirements for Internet Hosts -- Application and Support," RFC 1123, October 1989. Hibbs & Waters Expires: August 2004 [Page 35] Internet Draft DHCPv4 Server MIB February 2004 [RFC3410] Case, J., Mundy, R., Partain, D. and B. Stewart, "Introduction and Applicability Statements for Internet-Standard Management Framework", RFC 3410, December 2002. 10. Editors' Addresses Richard Barr Hibbs 952 Sanchez Street San Francisco, California 94114-3362 USA Phone: +1-(415)-648-3920 Fax: +1-(415)-648-9017 Email: rbhibbs@pacbell.net Glenn Waters Nortel Networks 310-875 Carling Avenue, Ottawa, Ontario K1S 5P1 Canada Phone: +1-(613)-798-4925 Email: gww@NortelNetworks.com 11. Full Copyright Statement Copyright (C), 2004, The Internet Society. All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING Hibbs & Waters Expires: August 2004 [Page 36] Internet Draft DHCPv4 Server MIB February 2004 BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Acknowledgement Funding for the RFC Editor function is currently provided by the Internet Society. Hibbs & Waters Expires: August 2004 [Page 37]