New version. Less duplication and a nice feature as bonus.
With softreconfig in enabled the looped prefixes are accepted
into the Adj-RIB-In.
This means that I can tell if my neighbor AS is using
a path via myself. Either I'm tired or that is cool.
router-02# bgpctl show rib 192.168.0.0
flags: * = Valid, > = Selected, I = via IBGP, A = Announced
origin: i = IGP, e = EGP, ? = Incomplete
flags destination gateway lpref med aspath origin
*> 192.168.0.0/16 192.168.100.5 100 0 65100 i
* 192.168.0.0/16 172.17.1.1 100 0 65200 65100 i
* 192.168.0.0/16 172.17.1.5 100 0 65200 65200 65200 65200
65100 i
router-02#
I now kill the peering that 65200 has to 65100, removing their
direct path to 192.168.0.0/16.
router-02# bgpctl show rib 192.168.0.0
flags: * = Valid, > = Selected, I = via IBGP, A = Announced
origin: i = IGP, e = EGP, ? = Incomplete
flags destination gateway lpref med aspath origin
*> 192.168.0.0/16 192.168.100.5 100 0 65100 i
router-02#
Sweet, the looping issue is gone.
Here is the bonus:
router-02# bgpctl show rib neigh 172.17.1.5 in | grep 65300
* 172.17.0.2/32 172.17.1.5 100 0 65200 65300 i
* 192.168.0.0/16 172.17.1.5 100 0 65200 65300 65100 i
* 192.168.100.4/30 172.17.1.5 100 0 65200 65300 i
router-02#
I now see the paths that the peer uses my network to access.
Note that this depends a bit on remote implementation.
I think this works agains a cisco router.
/Tony
Index: rde.c
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/rde.c,v
retrieving revision 1.228
diff -u -r1.228 rde.c
--- rde.c 16 Sep 2007 15:20:50 -0000 1.228
+++ rde.c 6 Nov 2007 17:08:50 -0000
@@ -919,12 +919,6 @@
/* shift to NLRI information */
p += 2 + attrpath_len;
- /* aspath needs to be loop free nota bene this is not a hard error */
- if (peer->conf.ebgp && !aspath_loopfree(asp->aspath, conf->as)) {
- error = 0;
- goto done;
- }
-
/* parse nlri prefix */
while (nlri_len > 0) {
if ((pos = rde_update_get_prefix(p, nlri_len, &prefix,
@@ -977,10 +971,18 @@
if (fasp == NULL)
fasp = asp;
- rde_update_log("update", peer, &fasp->nexthop->exit_nexthop,
- &prefix, prefixlen);
- path_update(peer, fasp, &prefix, prefixlen, F_LOCAL);
-
+ rde_update_log("update", peer,
+ &fasp->nexthop->exit_nexthop,&prefix,
+ prefixlen);
+ /* handle an update with loop as a withdraw */
+ if (peer->conf.ebgp && !aspath_loopfree(asp->aspath,
+ conf->as))
+ prefix_remove(peer, &prefix, prefixlen,
+ F_LOCAL);
+ else
+ path_update(peer, fasp, &prefix, prefixlen,
+ F_LOCAL);
+
/* free modified aspath */
if (fasp != asp)
path_put(fasp);
@@ -1075,9 +1077,15 @@
rde_update_log("update", peer,
&asp->nexthop->exit_nexthop,
- &prefix, prefixlen);
- path_update(peer, fasp, &prefix, prefixlen,
- F_LOCAL);
+ &prefix, prefixlen);
+ /* handle an update with loop as a withdraw */
+ if (peer->conf.ebgp &&
+ !aspath_loopfree(asp->aspath,conf->as))
+ prefix_remove(peer, &prefix,
+ prefixlen,F_LOCAL);
+ else
+ path_update(peer, fasp, &prefix,
+ prefixlen,F_LOCAL);
/* free modified aspath */
if (fasp != asp)
--
---
Tony Sarendal - [EMAIL PROTECTED]
IP/Unix
-= The scorpion replied,
"I couldn't help it, it's my nature" =-
