From 9d3f9705d8b386ccf006c106967c700141e5d049 Mon Sep 17 00:00:00 2001 From: Andrew Certain Date: Wed, 7 Nov 2012 23:50:07 +0000 Subject: bgpd: add replace-as modifier for BGP neighbor Added replace-as modifier for BGP neighbors when using local-as. If the replace-as modifier is specified, only the replacement AS as specified by the local-as modifier is prepended to the AS_PATH, not the process's AS. In bgp_attr.c, I decided that if (peer->change_local_as) { /* If replace-as is specified, we only use the change_local_as when advertising routes. */ if( ! CHECK_FLAG (peer->flags, PEER_FLAG_LOCAL_AS_REPLACE_AS) ) { aspath = aspath_add_seq (aspath, peer->local_as); } aspath = aspath_add_seq (aspath, peer->change_local_as); } else { aspath = aspath_add_seq (aspath, peer->local_as); } was clearer than the alternative that didn't duplicate the prepending of the process's AS: /* First, append the process local AS unless we have an alternate local_as * and we're replacing it (as opposed to just prepending it). */ if (! (peer->change_local_as && CHECK_FLAG (peer->flags, PEER_FLAG_LOCAL_AS_REPLACE_AS) ) ) { aspath = aspath_add_seq (aspath, peer->local_as); } if (peer->change_local_as) aspath = aspath_add_seq (aspath, peer->change_local_as); } But I could be convinced otherwise. Signed-off-by: David Lamparter --- bgpd/bgp_vty.c | 45 +++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 41 insertions(+), 4 deletions(-) (limited to 'bgpd/bgp_vty.c') diff --git a/bgpd/bgp_vty.c b/bgpd/bgp_vty.c index cb7ff1fa..0f288948 100644 --- a/bgpd/bgp_vty.c +++ b/bgpd/bgp_vty.c @@ -1570,7 +1570,7 @@ DEFUN (neighbor_local_as, if (! peer) return CMD_WARNING; - ret = peer_local_as_set (peer, atoi (argv[1]), 0); + ret = peer_local_as_set (peer, atoi (argv[1]), 0, 0); return bgp_vty_return (vty, ret); } @@ -1590,10 +1590,32 @@ DEFUN (neighbor_local_as_no_prepend, if (! peer) return CMD_WARNING; - ret = peer_local_as_set (peer, atoi (argv[1]), 1); + ret = peer_local_as_set (peer, atoi (argv[1]), 1, 0); return bgp_vty_return (vty, ret); } +DEFUN (neighbor_local_as_no_prepend_replace_as, + neighbor_local_as_no_prepend_replace_as_cmd, + NEIGHBOR_CMD2 "local-as " CMD_AS_RANGE " no-prepend replace-as", + NEIGHBOR_STR + NEIGHBOR_ADDR_STR2 + "Specify a local-as number\n" + "AS number used as local AS\n" + "Do not prepend local-as to updates from ebgp peers\n" + "Do not prepend local-as to updates from ibgp peers\n") +{ + struct peer *peer; + int ret; + + peer = peer_and_group_lookup_vty (vty, argv[0]); + if (! peer) + return CMD_WARNING; + + ret = peer_local_as_set (peer, atoi (argv[1]), 1, 1); + return bgp_vty_return (vty, ret); +} + + DEFUN (no_neighbor_local_as, no_neighbor_local_as_cmd, NO_NEIGHBOR_CMD2 "local-as", @@ -1631,6 +1653,17 @@ ALIAS (no_neighbor_local_as, "Specify a local-as number\n" "AS number used as local AS\n" "Do not prepend local-as to updates from ebgp peers\n") + +ALIAS (no_neighbor_local_as, + no_neighbor_local_as_val3_cmd, + NO_NEIGHBOR_CMD2 "local-as " CMD_AS_RANGE " no-prepend replace-as", + NO_STR + NEIGHBOR_STR + NEIGHBOR_ADDR_STR2 + "Specify a local-as number\n" + "AS number used as local AS\n" + "Do not prepend local-as to updates from ebgp peers\n" + "Do not prepend local-as to updates from ibgp peers\n") DEFUN (neighbor_password, neighbor_password_cmd, @@ -7494,10 +7527,12 @@ bgp_show_peer (struct vty *vty, struct peer *p) /* Configured IP address. */ vty_out (vty, "BGP neighbor is %s, ", p->host); vty_out (vty, "remote AS %u, ", p->as); - vty_out (vty, "local AS %u%s, ", + vty_out (vty, "local AS %u%s%s, ", p->change_local_as ? p->change_local_as : p->local_as, CHECK_FLAG (p->flags, PEER_FLAG_LOCAL_AS_NO_PREPEND) ? - " no-prepend" : ""); + " no-prepend" : "", + CHECK_FLAG (p->flags, PEER_FLAG_LOCAL_AS_REPLACE_AS) ? + " replace-as" : ""); vty_out (vty, "%s link%s", p->as == p->local_as ? "internal" : "external", VTY_NEWLINE); @@ -9175,9 +9210,11 @@ bgp_vty_init (void) /* "neighbor local-as" commands. */ install_element (BGP_NODE, &neighbor_local_as_cmd); install_element (BGP_NODE, &neighbor_local_as_no_prepend_cmd); + install_element (BGP_NODE, &neighbor_local_as_no_prepend_replace_as_cmd); install_element (BGP_NODE, &no_neighbor_local_as_cmd); install_element (BGP_NODE, &no_neighbor_local_as_val_cmd); install_element (BGP_NODE, &no_neighbor_local_as_val2_cmd); + install_element (BGP_NODE, &no_neighbor_local_as_val3_cmd); /* "neighbor password" commands. */ install_element (BGP_NODE, &neighbor_password_cmd); -- cgit v1.2.1