diff options
Diffstat (limited to 'bgpd/bgp_packet.c')
| -rw-r--r-- | bgpd/bgp_packet.c | 43 |
1 files changed, 30 insertions, 13 deletions
diff --git a/bgpd/bgp_packet.c b/bgpd/bgp_packet.c index 3ede2ce9fb..7137c1a784 100644 --- a/bgpd/bgp_packet.c +++ b/bgpd/bgp_packet.c @@ -974,14 +974,21 @@ static int bgp_collision_detect(struct peer *new, struct in_addr remote_id) return -1; } else if ((peer->status == OpenConfirm) || (peer->status == OpenSent)) { - /* 1. The BGP Identifier of the local system is compared - to - the BGP Identifier of the remote system (as specified - in - the OPEN message). */ - + /* 1. The BGP Identifier of the local system is + * compared to the BGP Identifier of the remote + * system (as specified in the OPEN message). + * + * If the BGP Identifiers of the peers + * involved in the connection collision + * are identical, then the connection + * initiated by the BGP speaker with the + * larger AS number is preserved. + */ if (ntohl(peer->local_id.s_addr) - < ntohl(remote_id.s_addr)) + < ntohl(remote_id.s_addr) + || (ntohl(peer->local_id.s_addr) + == ntohl(remote_id.s_addr) + && peer->local_as < peer->as)) if (!CHECK_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER)) { /* 2. If the value of the local BGP @@ -1005,10 +1012,13 @@ static int bgp_collision_detect(struct peer *new, struct in_addr remote_id) return -1; } else { - if (ntohl(peer->local_id.s_addr) == - ntohl(remote_id.s_addr)) - flog_err(EC_BGP_ROUTER_ID_SAME, "Peer's router-id %s is the same as ours", - inet_ntoa(remote_id)); + if (ntohl(peer->local_id.s_addr) + == ntohl(remote_id.s_addr) + && peer->local_as == peer->as) + flog_err( + EC_BGP_ROUTER_ID_SAME, + "Peer's router-id %s is the same as ours", + inet_ntoa(remote_id)); /* 3. Otherwise, the local system closes newly created @@ -1197,10 +1207,17 @@ static int bgp_open_receive(struct peer *peer, bgp_size_t size) } } - /* remote router-id check. */ + /* rfc6286: + * If the BGP Identifier field of the OPEN message + * is zero, or if it is the same as the BGP Identifier + * of the local BGP speaker and the message is from an + * internal peer, then the Error Subcode is set to + * "Bad BGP Identifier". + */ if (remote_id.s_addr == INADDR_ANY || IPV4_CLASS_DE(ntohl(remote_id.s_addr)) - || ntohl(peer->local_id.s_addr) == ntohl(remote_id.s_addr)) { + || (peer->sort == BGP_PEER_IBGP + && ntohl(peer->local_id.s_addr) == ntohl(remote_id.s_addr))) { if (bgp_debug_neighbor_events(peer)) zlog_debug("%s bad OPEN, wrong router identifier %s", peer->host, inet_ntoa(remote_id)); |