| < draft-ietf-msdp-spec-05.txt | draft-ietf-msdp-spec-06.txt > | |||
|---|---|---|---|---|
| Network Working Group Dino Farinacci | Network Working Group Dino Farinacci | |||
| INTERNET DRAFT Procket Networks | INTERNET DRAFT Procket Networks | |||
| Yakov Rekhter | Yakov Rekhter | |||
| David Meyer | David Meyer | |||
| Cisco Systems | Cisco Systems | |||
| Peter Lothberg | Peter Lothberg | |||
| Sprint | Sprint | |||
| Hank Kilmer | Hank Kilmer | |||
| Jeremy Hall | Jeremy Hall | |||
| UUnet | UUnet | |||
| Category Standards Track | Category Standards Track | |||
| February, 2000 | July, 2000 | |||
| Multicast Source Discovery Protocol (MSDP) | Multicast Source Discovery Protocol (MSDP) | |||
| <draft-ietf-msdp-spec-05.txt> | <draft-ietf-msdp-spec-06.txt> | |||
| 1. Status of this Memo | 1. Status of this Memo | |||
| This document is an Internet-Draft and is in full conformance with | This document is an Internet-Draft and is in full conformance with | |||
| all provisions of Section 10 of RFC 2026. | all provisions of Section 10 of RFC 2026. | |||
| Internet Drafts are working documents of the Internet Engineering | Internet Drafts are working documents of the Internet Engineering | |||
| Task Force (IETF), its areas, and its working groups. Note that other | Task Force (IETF), its areas, and its working groups. Note that other | |||
| groups may also distribute working documents as Internet-Drafts. | groups may also distribute working documents as Internet-Drafts. | |||
| skipping to change at page 6, line 7 ¶ | skipping to change at page 6, line 7 ¶ | |||
| Each entry in an SA Cache has an associated SA-State-Timer. A | Each entry in an SA Cache has an associated SA-State-Timer. A | |||
| (S,G)-SA-State-Timer is started when an (S,G)-SA message is initially | (S,G)-SA-State-Timer is started when an (S,G)-SA message is initially | |||
| received by a caching MSDP peer. The timer is reset to [SA-State- | received by a caching MSDP peer. The timer is reset to [SA-State- | |||
| Period] if another (S,G)-SA message is received before the (S,G)-SA- | Period] if another (S,G)-SA message is received before the (S,G)-SA- | |||
| State-Timer expires. [SA-State-Period] MUST NOT be less than 90 | State-Timer expires. [SA-State-Period] MUST NOT be less than 90 | |||
| seconds. | seconds. | |||
| 8.4. SA-Hold-Down-Timer | 8.4. SA-Hold-Down-Timer | |||
| A caching MSDP peer SHOULD NOT forward an SA message it has received | The per-(S,G) timer is set to [SA-Hold-Down-Period] when forwarding | |||
| in during the previous [SA-Hold-Down-Period] seconds. [SA-Hold-Down- | an SA message, and a SA message MUST only be forwarded when it's | |||
| Period] SHOULD be set to 30 seconds. The per-SA message timer is set | associated timer is not running. [SA-Hold-Down-Period] SHOULD be set | |||
| to [SA-Hold-Down-Period] when forwarding an (S,G)-SA message, and a | to 30 seconds. A caching MSDP peer MUST NOT forward a (S,G)-SA | |||
| (S,G)-SA message MUST only be forwarded when it's associated timer is | message it has received in during the previous [SA-Hold-Down-Period] | |||
| not running. Finally, the timer is deleted when the (S,G)-SA cache | seconds. Finally, the timer is deleted when the SA cache entry is | |||
| entry is deleted. | deleted. | |||
| 8.5. KeepAlive Timer | 8.5. KeepAlive Timer | |||
| The KeepAlive timer is used by the active connect side of the MSDP | The KeepAlive timer contols when to send MSDP KeepAlive messages. In | |||
| connection to track the state of the passive-connect side of the | particular, the KeepAlive timer is used to reset the TCP connection | |||
| connection. In particular, the KeepAlive timer is used to reset the | when the passive-connect side of the connection goes down. The | |||
| TCP connection when the passive-connect side of the connection goes | KeepAlive timer is set to [KeepAlive-Period] when the passive-connect | |||
| down. The KeepAlive timer is set to [KeepAlive-Period] when the | peer comes up. [KeepAlive-Period] SHOULD NOT be less that 75 seconds. | |||
| passive-connect peer comes up. [KeepAlive-Period] SHOULD NOT be less | The timer is reset to [KeepAlive-Period] upon receipt of an MSDP | |||
| that 75 seconds. The timer is reset to [KeepAlive-Period] upon | message from peer, and deleted when the timer expires or the | |||
| receipt of an MSDP message from peer, and deleted when the timer | passive-connect peer closes the connection. | |||
| expires or the passive-connect peer closes the connection. | ||||
| 8.6. ConnectRetry Timer | 8.6. ConnectRetry Timer | |||
| The ConnectRetry timer is used by an MSDP peer to transition from | The ConnectRetry timer is used by an MSDP peer to transition from | |||
| INACTIVE to CONNECTING states. There is one timer per peer, and the | INACTIVE to CONNECTING states. There is one timer per peer, and the | |||
| [ConnectRetry-Period] SHOULD be set to 30 seconds. The timer is | [ConnectRetry-Period] SHOULD be set to 30 seconds. The timer is | |||
| initialized to [ConnectRetry-Period] when an MSDP peer's active | initialized to [ConnectRetry-Period] when an MSDP peer's active | |||
| connect attempt fails. When the timer expires, the peer retries the | connect attempt fails. When the timer expires, the peer retries the | |||
| connection and the timer is reset to [ConnectRetry-Period]. It is | connection and the timer is reset to [ConnectRetry-Period]. It is | |||
| deleted if either the connection transitions into ESTABLISHED state | deleted if either the connection transitions into ESTABLISHED state | |||
| skipping to change at page 7, line 23 ¶ | skipping to change at page 7, line 22 ¶ | |||
| As the number of (S,G) pairs increases in the Internet, an RP may | As the number of (S,G) pairs increases in the Internet, an RP may | |||
| want to filter which sources it describes in SA messages. Also, | want to filter which sources it describes in SA messages. Also, | |||
| filtering may be used as a matter of policy which at the same time | filtering may be used as a matter of policy which at the same time | |||
| can reduce state. Only the RP co-located in the same domain as the | can reduce state. Only the RP co-located in the same domain as the | |||
| source can restrict SA messages. Note, however, that MSDP peers in | source can restrict SA messages. Note, however, that MSDP peers in | |||
| transit domains should not filter SA messages or the flood-and-join | transit domains should not filter SA messages or the flood-and-join | |||
| model can not guarantee that sources will be known throughout the | model can not guarantee that sources will be known throughout the | |||
| Internet (i.e., SA filtering by transit domains can cause undesired | Internet (i.e., SA filtering by transit domains can cause undesired | |||
| lack of connectivity). In general, policy should be expressed using | lack of connectivity). In general, policy should be expressed using | |||
| MBGP [RFC2283]. This will cause MSDP messages will flow in the | MBGP [RFC2283]. This will cause MSDP messages to flow in the desired | |||
| desired direction and peer-RPF fail otherwise. An exception occurs at | direction and peer-RPF fail otherwise. An exception occurs at an | |||
| an administrative scope [RFC2365] boundary. In particular, a SA | administrative scope [RFC2365] boundary. In particular, a SA message | |||
| message for a (S,G) MUST NOT be sent to peers which are on the other | for a (S,G) MUST NOT be sent to peers which are on the other side of | |||
| side of an administrative scope boundary for G. | an administrative scope boundary for G. | |||
| 11. SA Requests | 11. SA Requests | |||
| If an MSDP peer decides to cache SA state, it MAY accept SA-Requests | If an MSDP peer decides to cache SA state, it MAY accept SA-Requests | |||
| from other MSDP peers. When an MSDP peer receives an SA-Request for a | from other MSDP peers. When an MSDP peer receives an SA-Request for a | |||
| group range, it will respond to the peer with a set of SA entries, in | group range, it will respond to the peer with a set of SA entries, in | |||
| an SA-Response message, for all active sources sending to the group | an SA-Response message, for all active sources sending to the group | |||
| range requested in the SA-Request message. The peer that sends the | range requested in the SA-Request message. The peer that sends the | |||
| request will not flood the responding SA-Response message to other | request will not flood the responding SA-Response message to other | |||
| peers. See section 17 for discussion of error handling relating to SA | peers. See section 17 for discussion of error handling relating to SA | |||
| skipping to change at page 8, line 46 ¶ | skipping to change at page 8, line 46 ¶ | |||
| 14.1. Peer-RPF Forwarding Rules | 14.1. Peer-RPF Forwarding Rules | |||
| An SA message originated by an MSDP originator R and received by a | An SA message originated by an MSDP originator R and received by a | |||
| MSDP router from MSDP peer N is accepted if N is the appropriate RPF | MSDP router from MSDP peer N is accepted if N is the appropriate RPF | |||
| neighbor for originator R (the RP in the SA message), and discarded | neighbor for originator R (the RP in the SA message), and discarded | |||
| otherwise. | otherwise. | |||
| The RPF neighbor is chosen using the first of the following rules | The RPF neighbor is chosen using the first of the following rules | |||
| that matches: | that matches: | |||
| (i). R is the RPF neighbor if we have an MSDP peering with R. | (i). R is the RPF neighbor if we have an MSDP peering with R, | |||
| and R is the next hop towards the prefix covering the RP | ||||
| in the SA message. | ||||
| (ii). The external MBGP neighbor towards which we are | (ii). The external MBGP neighbor towards which we are | |||
| poison-reversing the MBGP route towards R is the RPF neighbor | poison-reversing the MBGP route towards R is the RPF neighbor | |||
| if we have an MSDP peering with it. | if we have an MSDP peering with it. | |||
| (iii). If we have any MSDP peerings with neighbors in the first | (iii). If we have any MSDP peerings with neighbors in the first | |||
| AS along the AS_PATH (the AS from which we learned this | AS along the AS_PATH (the AS from which we learned this | |||
| route), but no external MBGP peerings with them, | route), but no external MBGP peerings with them, | |||
| the neighbor with the highest IP address is the RPF neighbor. | the neighbor with the highest IP address is the RPF neighbor. | |||
| (vi). The internal MBGP advertiser of the router towards R is | (iv). The internal MBGP advertiser of the router towards R is | |||
| the RPF neighbor if we have an MSDP peering with it. | the RPF neighbor if we have an MSDP peering with it. | |||
| (v). If none of the above match, and we have an MSDP | (v). If none of the above match, and we have an MSDP | |||
| default-peer configured, the MSDP default-peer is | default-peer configured, the MSDP default-peer is | |||
| the RPF neighbor. | the RPF neighbor. | |||
| 14.2. MSDP default-peer semantics | 14.2. MSDP default-peer semantics | |||
| An MSDP default-peer is much like a default route. It is intended to | An MSDP default-peer is much like a default route. It is intended to | |||
| be used in those cases where a stub network isn't running BGP or | be used in those cases where a stub network isn't running BGP. An | |||
| MBGP. An MSDP peer configured with a default-peer accepts all SA | MSDP peer configured with a default-peer accepts all SA messages from | |||
| messages from the default-peer. Note that a router running BGP or | the default-peer. Note that a router running BGP SHOULD NOT allow | |||
| MBGP SHOULD NOT allow configuration of default peers, since this | configuration of default peers, since this allows the possibility for | |||
| allows the possibility for SA looping or black-holes to occur. | SA looping or black-holes to occur. | |||
| 14.3. MSDP mesh-group semantics | ||||
| A MSDP mesh-group is a operational mechanism for reducing SA | ||||
| flooding, typically in an intra-domain setting. In particular, when | ||||
| some subset of a domain's MSDP speakers are fully meshed, then can be | ||||
| configured into a mesh-group. The semantics of the mesh-group are as | ||||
| follows: | ||||
| (i). If a member R of a mesh-group M receives a SA message from an | ||||
| MSDP peer that is also a member of mesh-group M, R accepts the | ||||
| SA message and forwards it to all of it's peers that are not | ||||
| part of any mesh-group. R MUST NOT forward the SA message to | ||||
| other members of mesh-group M. | ||||
| (ii). If a member R of a mesh-group M receives a SA message from an | ||||
| MSDP peer that is not a member of mesh-group M, and the SA | ||||
| message passes the peer-RPF check, then R forwards the SA | ||||
| message to all members of mesh-group M. | ||||
| Note that since mesh-groups suspend peer-RPF checking of SAs received | ||||
| from a mesh-group member ((i). above), they allow for mis- | ||||
| configuration to cause SA looping. | ||||
| 15. MSDP Connection Establishment | 15. MSDP Connection Establishment | |||
| MSDP messages will be encapsulated in a TCP connection. An MSDP peer | MSDP messages will be encapsulated in a TCP connection. An MSDP peer | |||
| listens for new TCP connections on port 639. One side of the MSDP | listens for new TCP connections on port 639. One side of the MSDP | |||
| peering relationship will listen on the well-known port and the other | peering relationship will listen on the well-known port and the other | |||
| side will do an active connect to the well-known port. The side with | side will do an active connect to the well-known port. The side with | |||
| the higher peer IP address will do the listen. This connection | the higher peer IP address will do the listen. This connection | |||
| establishment algorithm avoids call collision. Therefore, there is no | establishment algorithm avoids call collision. Therefore, there is no | |||
| need for a call collision procedure. It should be noted, however, | need for a call collision procedure. It should be noted, however, | |||
| skipping to change at page 13, line 32 ¶ | skipping to change at page 14, line 32 ¶ | |||
| 16.2.2. IPv4 Source-Active Request TLV | 16.2.2. IPv4 Source-Active Request TLV | |||
| The Source-Active Request is used to request SA-state from a caching | The Source-Active Request is used to request SA-state from a caching | |||
| MSDP peer. If an RP in a domain receives a PIM Join message for a | MSDP peer. If an RP in a domain receives a PIM Join message for a | |||
| group, creates (*,G) state and wants to know all active sources for | group, creates (*,G) state and wants to know all active sources for | |||
| group G, and it has been configured to peer with an SA-state caching | group G, and it has been configured to peer with an SA-state caching | |||
| peer, it may send an SA-Request message for the group. | peer, it may send an SA-Request message for the group. | |||
| 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 | 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | 2 | 8 | Gprefix Len | | | 2 | 8 | Reserved | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | Group Address Prefix | | | Group Address Prefix | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| Type | Type | |||
| IPv4 Source-Active Request TLV is type 2. | IPv4 Source-Active Request TLV is type 2. | |||
| Gprefix Len | Reserved | |||
| The route prefix length associated with the group address prefix. | Must be transmitted as zero and ignored on receipt. | |||
| Group Address | Group Address | |||
| The group address the MSDP peer is requesting. | The group address the MSDP peer is requesting. | |||
| 16.2.3. IPv4 Source-Active Response TLV | 16.2.3. IPv4 Source-Active Response TLV | |||
| The Source-Active Response is sent in response to a Source-Active | The Source-Active Response is sent in response to a Source-Active | |||
| Request message. The Source-Active Response message has the same | Request message. The Source-Active Response message has the same | |||
| format as a Source-Active message but does not allow encapsulation of | format as a Source-Active message but does not allow encapsulation of | |||
| multicast data. | multicast data. | |||
| skipping to change at page 18, line 8 ¶ | skipping to change at page 19, line 15 ¶ | |||
| 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 | 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | 5 | 16 |O| 2 | | | 5 | 16 |O| 2 | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | 1 | Reserved | Gprefix Len | | | 1 | Reserved | Gprefix Len | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | Gprefix | | | Gprefix | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | Group Address | | | Group Address | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| y.fi | ||||
| If a caching MSDP peer receives a request for an invalid | If a caching MSDP peer receives a request for an invalid group, it | |||
| group, it returns the following notification: | returns the following notification: | |||
| 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 | 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | 5 | 16 |O| 2 | | | 5 | 16 |O| 2 | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | 2 | Reserved | Gprefix Len | | | 2 | Reserved | Gprefix Len | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | Gprefix | | | Gprefix | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | Invalid Group Address | | | Invalid Group Address | | |||
| skipping to change at page 22, line 42 ¶ | skipping to change at page 24, line 42 ¶ | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| |C| Reserved0 | Ver | [MSDP-GRE-ProtocolType] |\ | |C| Reserved0 | Ver | [MSDP-GRE-ProtocolType] |\ | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ GRE Header | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ GRE Header | |||
| | Checksum (optional) | Reserved1 |/ | | Checksum (optional) | Reserved1 |/ | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | Originating RP IPv4 Address |\ | | Originating RP IPv4 Address |\ | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Payload | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Payload | |||
| | (S,G) Data Packet .... / | | (S,G) Data Packet .... / | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| MSDP-GRE-ProtocolType is set to 0x876C, pending IANA approval | ||||
| [ETYPES,RFC1700]. | ||||
| 18.2.1. Encapsulation and Path MTU Discovery [RFC1191] | 18.2.1. Encapsulation and Path MTU Discovery [RFC1191] | |||
| Existing implementations of GRE, when using IPv4 as the Delivery | Existing implementations of GRE, when using IPv4 as the Delivery | |||
| Header, do not implement Path MTU discovery and do not set the Don't | Header, do not implement Path MTU discovery and do not set the Don't | |||
| Fragment bit in the Delivery Header. This can cause large packets to | Fragment bit in the Delivery Header. This can cause large packets to | |||
| become fragmented within the tunnel and reassembled at the tunnel | become fragmented within the tunnel and reassembled at the tunnel | |||
| exit (independent of whether the payload packet is using PMTU). If a | exit (independent of whether the payload packet is using PMTU). If a | |||
| tunnel entry point were to use Path MTU discovery, however, that | tunnel entry point were to use Path MTU discovery, however, that | |||
| tunnel entry point would also need to relay ICMP unreachable error | tunnel entry point would also need to relay ICMP unreachable error | |||
| messages (in particular the "fragmentation needed and DF set" code) | messages (in particular the "fragmentation needed and DF set" code) | |||
| back to the originator of the packet, which is not required by the | back to the originator of the packet, which is not required by the | |||
| GRE specification [GRE]. Failure to properly relay Path MTU | GRE specification [RFC2784]. Failure to properly relay Path MTU | |||
| information to an originator can result in the following behavior: | information to an originator can result in the following behavior: | |||
| the originator sets the don't fragment bit, the packet gets dropped | the originator sets the don't fragment bit, the packet gets dropped | |||
| within the tunnel, but since the originator doesn't receive proper | within the tunnel, but since the originator doesn't receive proper | |||
| feedback, it retransmits with the same PMTU, causing subsequently | feedback, it retransmits with the same PMTU, causing subsequently | |||
| transmitted packets to be dropped. | transmitted packets to be dropped. | |||
| 18.3. TCP Data Encapsulation | 18.3. TCP Data Encapsulation | |||
| As discussed earlier, encapsulation of data in SA messages MAY be | As discussed earlier, encapsulation of data in SA messages MAY be | |||
| supported for backwards compatibility with legacy MSDP peers. | supported for backwards compatibility with legacy MSDP peers. | |||
| skipping to change at page 23, line 36 ¶ | skipping to change at page 26, line 8 ¶ | |||
| natively. Route filtering will remain unchanged. However packet | natively. Route filtering will remain unchanged. However packet | |||
| filtering at a firewall requires either that a firewall look inside | filtering at a firewall requires either that a firewall look inside | |||
| the GRE packet or that the filtering is done on the GRE tunnel | the GRE packet or that the filtering is done on the GRE tunnel | |||
| endpoints. In those environments in which this is considered to be a | endpoints. In those environments in which this is considered to be a | |||
| security issue it may be desirable to terminate the tunnel at the | security issue it may be desirable to terminate the tunnel at the | |||
| firewall. | firewall. | |||
| 20. Acknowledgments | 20. Acknowledgments | |||
| The authors would like to thank Bill Nickless, John Meylor, Liming | The authors would like to thank Bill Nickless, John Meylor, Liming | |||
| Wei, Manoj Leelanivas, Mark Turner, John Zwiebel, and Cristina | Wei, Manoj Leelanivas, Mark Turner, John Zwiebel, Cristina | |||
| Radulescu-Banu for their design feedback and comments. In addition to | Radulescu-Banu and IJsbrand Wijnands for their design feedback and | |||
| many other contributions, Tom Pusateri helped to clarify the | comments. In addition to many other contributions, Tom Pusateri | |||
| connection state machine, Dave Thaler helped to clarify the | helped to clarify the connection state machine, Dave Thaler helped to | |||
| Notification message types, and Bill Fenner helped to clarify the | clarify the Notification message types, and Bill Fenner helped to | |||
| Peer-RPF rules. | clarify the Peer-RPF rules. | |||
| 21. Author's Address: | 21. Author's Address: | |||
| Dino Farinacci | Dino Farinacci | |||
| Procket Networks | Procket Networks | |||
| 3850 No. First St., Ste. C | 3850 No. First St., Ste. C | |||
| San Jose, CA 95134 | San Jose, CA 95134 | |||
| Email: dino@procket.com | Email: dino@procket.com | |||
| Yakov Rehkter | Yakov Rehkter | |||
| skipping to change at page 25, line 7 ¶ | skipping to change at page 28, line 7 ¶ | |||
| Email: jhall@uu.net | Email: jhall@uu.net | |||
| David Meyer | David Meyer | |||
| Cisco Systems, Inc. | Cisco Systems, Inc. | |||
| 170 Tasman Drive | 170 Tasman Drive | |||
| San Jose, CA, 95134 | San Jose, CA, 95134 | |||
| Email: dmm@cisco.com | Email: dmm@cisco.com | |||
| 22. REFERENCES | 22. REFERENCES | |||
| [GRE] Farinacci, D., et al., "Generic Routing Encapsulation | [ETYPES] ftp://ftp.isi.edu/in-notes/iana/assignments/ethernet-numbers | |||
| (GRE)", draft-meyer-gre-update-03.txt, January, | ||||
| 2000. Work in Progress. | [RFC1700] J. Reynolds and J. Postel, "Assigned Numbers", RFC 1700, | |||
| October, 1994. | ||||
| [RFC2784] Farinacci, D., et al., "Generic Routing Encapsulation | ||||
| (GRE)", RFC 2784, March 2000. | ||||
| [RFC768] Postel, J. "User Datagram Protocol", RFC 768, August, | [RFC768] Postel, J. "User Datagram Protocol", RFC 768, August, | |||
| 1980. | 1980. | |||
| [RFC1191] Mogul, J., and S. Deering, "Path MTU Discovery", | [RFC1191] Mogul, J., and S. Deering, "Path MTU Discovery", | |||
| RFC 1191, November 1990. | RFC 1191, November 1990. | |||
| [RFC1771] Rekhter, Y., and T. Li, "A Border Gateway Protocol 4 | [RFC1771] Rekhter, Y., and T. Li, "A Border Gateway Protocol 4 | |||
| (BGP-4)", RFC 1771, March 1995. | (BGP-4)", RFC 1771, March 1995. | |||
| End of changes. 18 change blocks. | ||||
| 48 lines changed or deleted | 77 lines changed or added | |||
This html diff was produced by rfcdiff 1.48. The latest version is available from http://tools.ietf.org/tools/rfcdiff/ | ||||