Mailing List Archive

Please do not reply directly to this email. All additional
comments should be made in the comments box of this bug
report.

http://bugzilla.quagga.net/show_bug.cgi?id=321

Summary: Severe oscillation in BGP confederation setups
Product: Quagga
Version: unspecified
Platform: All
OS/Version: All
Status: UNCONFIRMED
Severity: major
Priority: Very High
Component: bgpd
AssignedTo: maintainers@quagga.net
ReportedBy: acinonyxs@yahoo.gr


- Occurs when receiving the same prefix from more than one confederation peers
- Oscillation with half-period = BGP Scan Time
- Doesn't occur when there are no alternative routes
- Doesn't occur when there are no IGP metrics

Suggested solution:

- Currently the route is installed without nexthop lookup and no IGP metric. IGP
metric for the latter route is "0" and gets selected as bestpath over routes
with igpmetric set. On scantimer timout it receives its proper metric or gets
invalid. This causes oscillation.
- Nexthop reachability should be looked-up before installing the route.

Patch follows against 0.98.6:

diff -Nur quagga-0.98.6/bgpd/bgp_route.c quagga-0.98.6-patched/bgpd/bgp_route.c
--- quagga-0.98.6/bgpd/bgp_route.c 2006-05-08 18:03:25.000000000 +0300
+++ quagga-0.98.6-patched/bgpd/bgp_route.c 2006-12-08 23:10:37.000000000 +0200
@@ -1815,6 +1815,7 @@
if ((afi == AFI_IP || afi == AFI_IP6)
&& safi == SAFI_UNICAST
&& (peer_sort (peer) == BGP_PEER_IBGP
+ || peer_sort (peer) == BGP_PEER_CONFED
|| (peer_sort (peer) == BGP_PEER_EBGP && peer->ttl != 1)
|| CHECK_FLAG (peer->flags, PEER_FLAG_ENFORCE_MULTIHOP)))
{
@@ -1862,6 +1863,7 @@
if ((afi == AFI_IP || afi == AFI_IP6)
&& safi == SAFI_UNICAST
&& (peer_sort (peer) == BGP_PEER_IBGP
+ || peer_sort (peer) == BGP_PEER_CONFED
|| (peer_sort (peer) == BGP_PEER_EBGP && peer->ttl != 1)
|| CHECK_FLAG (peer->flags, PEER_FLAG_ENFORCE_MULTIHOP)))
{



------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.
_______________________________________________
Quagga-bugs mailing list
Quagga-bugs@lists.quagga.net
http://lists.quagga.net/mailman/listinfo/quagga-bugs