[quagga-users 7388] Quagga 0.99.4 bgp seems to accept routes from own AS

Bartek Kania mrbk at gnarf.org
Sun Aug 6 02:27:52 IST 2006


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hi!
I have a little play-setup of a couple of quagga routers speaking EBGP
and some speaking IBGP and I just noticed that the one router that
runs 0.99.4 shows routes containing it's own AS when doing a
   show ip bgp summary


My AS is 64692, and the following is what I get:
BGP table version is 0, local router ID is 192.168.42.69
Status codes: s suppressed, d damped, h history, * valid, > best, i -
internal,
               r RIB-failure, S Stale, R Removed
Origin codes: i - IGP, e - EGP, ? - incomplete

    Network          Next Hop            Metric LocPrf Weight Path
*  192.168.42.0     192.168.255.2                          0 64999
64692 i
*>i                 192.168.255.6          100    100      0 64692 i
*> 192.168.66.0     192.168.255.18           0             0 64998 i
*                   192.168.255.2                          0 64999
64998 i
* i                 192.168.255.6          100    100      0 64692
64999 64998 i*  192.168.82.0     192.168.255.18
0 64998 64999 i
*>                  192.168.255.2            0             0 64999 i
* i                 192.168.255.6          100    100      0 64692
64999 i
*  192.168.255.0/30 192.168.255.2            0             0 64999 i
* i                 192.168.255.6          100    100      0 64692
64999 i
*>                  0.0.0.0                  0         32768 i
*  192.168.255.4/30 192.168.255.2                          0 64999
64692 i
* i                 192.168.255.6          100    100      0 64692 i
*>                  0.0.0.0                  0         32768 i
*  192.168.255.8/30 192.168.255.18                         0 64998
64999 i
*>                  192.168.255.2            0             0 64999 i
* i                 192.168.255.6          100    100      0 64692 i
*  192.168.255.12/30
                     192.168.255.18           0             0 64998 i
*>                  192.168.255.2            0             0 64999 i
* i                 192.168.255.6          100    100      0 64692
64999 i
*  192.168.255.16/30
                     192.168.255.18           0             0 64998 i
*                   192.168.255.2                          0 64999
64998 i
*>                  0.0.0.0                  0         32768 i

Total number of prefixes 8


Looking at the 192.168.42.0 network it has it's own AS-number in the
as-path. 
A closer look reveals:

BGP routing table entry for 192.168.42.0/24
Paths: (2 available, best #2, table Default-IP-Routing-Table)
   Advertised to non peer-group peers:
   192.168.255.2 192.168.255.18
   64999 64692
     192.168.255.2 from 192.168.255.2 (192.168.255.10)
       Origin IGP, localpref 100, valid, external
       Last update: Sun Aug  6 01:09:15 2006

   64692
     192.168.255.6 (metric 1) from 192.168.255.6 (192.168.255.6)
       Origin IGP, metric 100, localpref 100, valid, internal, best
       Last update: Sun Aug  6 01:09:14 2006

The first entry should not be there,
and in fact when downgrading to 0.98.6 it isn't there.

My configuration is as follows:
router bgp 64692
  bgp router-id 192.168.42.69
  network 192.168.255.0/30
  network 192.168.255.4/30
  network 192.168.255.16/30
  neighbor ebn peer-group
  neighbor ebn soft-reconfiguration inbound
  neighbor ebn prefix-list ebn in
  neighbor ebn prefix-list ebn out
  neighbor ebn route-map PARSE-COMMUNITIES in
  neighbor 192.168.255.2 remote-as 64999
  neighbor 192.168.255.2 peer-group ebn
  neighbor 192.168.255.6 remote-as 64692
  neighbor 192.168.255.6 next-hop-self
  neighbor 192.168.255.6 soft-reconfiguration inbound
  neighbor 192.168.255.18 remote-as 64998
  neighbor 192.168.255.18 peer-group ebn
ip prefix-list ebn seq 5 permit 192.168.0.0/16 le 32
ip prefix-list ebn seq 10 deny any
!
ip community-list standard COM-BLACKHOLE permit 64692:101
ip community-list standard COM-BLACKHOLE deny internet
ip community-list standard COM-NOEXPORT permit 64692:100
ip community-list standard COM-NOEXPORT deny internet
!
route-map PARSE-COMMUNITIES permit 10
  match community COM-NOEXPORT
  on-match next
  set community no-export additive
!
route-map PARSE-COMMUNITIES permit 20
  match community COM-BLACKHOLE
  on-match next
  set community no-export additive
  set ip next-hop 127.0.0.2
!
route-map PARSE-COMMUNITIES permit 30

/B
- -- 
* GPG-Key: http://evil.gnarf.org/mrbk.pgp

A: Because we read from top to bottom, left to right.
Q: Why should i start my reply below the quoted text?
- -- http://www.i-hate-computers.demon.co.uk/

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.1 (GNU/Linux)

iD8DBQFE1Sl+ckvkFeO3ANARAp5jAJ4mLtge8YOuEyH3lOahlyv/1EqbVACfQrhl
VSYFrcdj3gq6cyb9jB/cdmo=
=NXmf
-----END PGP SIGNATURE-----


More information about the Quagga-users mailing list