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BGP + OSP problem - Cisco

Topology attached.


Problem: R31 (and then ISP2) do not learn about BGP 25.25.25.25 from R32

Some show commands:

show ip bgp summary

R17#sh ip bg sum
BGP router identifier 192.168.200.2, local AS number 9000
Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.200.1   4  9000      70      14       90    0    0 00:09:50        5
192.168.200.3   4  9000      52      14       90    0    0 00:09:57        5


R32#sh ip bg su
BGP router identifier 192.168.200.1, local AS number 9000
Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
5.5.5.1         4 10000      19      54      100    0    0 00:11:27        6
192.168.1.2     4  9000      41      77      103    0    0 00:11:36        5
192.168.200.2   4  9000      15      77      103    0    0 00:10:57        1
192.168.200.3   4  9000      57      76      103    0    0 00:10:38        5



R31#sh ip bg sum
BGP router identifier 192.168.3.2, local AS number 9000
Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
6.6.6.1         4 20000      22      40       53    0    0 00:13:02        6
192.168.1.1     4  9000      84      46       55    0    0 00:12:40        5

Open in new window



i am redistributing bgp into ospf on R17 by using: redistribute bgp 9000 subnets.

That is why I've got ' RIB-failure' on R32. But I 've read it should NOT stop bgp neighbors from advertising this network.

here is 'sh ip bgp'


R32#sh ip bgp
BGP table version is 130, local router ID is 192.168.200.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
r> 5.5.5.0/30       5.5.5.1                  0             0 10000 i
* i6.6.6.0/30       33.33.33.1               0    100      0 40000 30000 20000 i
*>                  5.5.5.1                                0 10000 30000 20000 i
* i                 6.6.6.1                  0    100      0 20000 i
* i15.15.15.0/30    33.33.33.1               0    100      0 40000 30000 20000 i
*>                  5.5.5.1                                0 10000 30000 20000 i
* i                 6.6.6.1                  0    100      0 20000 i
* i16.16.16.0/30    33.33.33.1               0    100      0 40000 30000 i
*>                  5.5.5.1                                0 10000 30000 i
* i                 6.6.6.1                  0    100      0 20000 30000 i
* i17.17.17.0/30    33.33.33.1               0    100      0 40000 30000 i
*>                  5.5.5.1                                0 10000 30000 i
* i                 6.6.6.1                  0    100      0 20000 30000 i
r>i25.25.25.25/32   192.168.200.2            0    100      0 i
*>i33.33.33.0/30    33.33.33.1               0    100      0 40000 i
*                   5.5.5.1                                0 10000 30000 40000 i
* i                 6.6.6.1                  0    100      0 20000 30000 40000 i




R31#sh ip bgp
BGP table version is 69, local router ID is 192.168.3.2
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*  5.5.5.0/30       6.6.6.1                                0 20000 30000 10000 i
*>i                 5.5.5.1                  0    100      0 10000 i
r i6.6.6.0/30       5.5.5.1                  0    100      0 10000 30000 20000 i
r>                  6.6.6.1                  0             0 20000 i
* i15.15.15.0/30    5.5.5.1                  0    100      0 10000 30000 20000 i
*>                  6.6.6.1                  0             0 20000 i
* i16.16.16.0/30    5.5.5.1                  0    100      0 10000 30000 i
*>                  6.6.6.1                                0 20000 30000 i
* i17.17.17.0/30    5.5.5.1                  0    100      0 10000 30000 i
*>                  6.6.6.1                                0 20000 30000 i
*> 33.33.33.0/30    6.6.6.1                                0 20000 30000 40000 i


R31#sh ip route | i 25.25.25.25
O E2    25.25.25.25 [110/1] via 192.168.3.1, 00:16:41, FastEthernet1/0

Open in new window


R31 cannot see 25.25.25.25 from bgp, it can see it from ospf only and as a result ISP2 does not see it either. On the other hand ISP1 can see 25.25.25.25 in its routing table.
Why? And how to fix it so ISP2 knows about 25.25.25.25
bgp-problem.png
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m1979
Asked:
m1979
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2 Solutions
 
harbor235Commented:
Well OSPF has a lower Administrative distance so it will prefer OSPF for router 25.25.25.25


harbor235 ;}
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m1979Author Commented:
that is correct harbor235 but does not explain why R31 did not learn about bgp route from R32. As a result - ISP2 which is bgp router only does not have a direct bgp route to 25.25.25.25
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harbor235Commented:
Filters?


harbor235 ;}
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m1979Author Commented:
No, nothing like this. I sorted it by creating a neighbour between R31 and R17 but... it should work without it?
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harbor235Commented:
Can you verify you are advertising it outbound?

show ip bgp regexp ^$   - your route show show up her eif it is being advertised



harbor235 ;}
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m1979Author Commented:
Found it on a different board - split horizon iBGP.

Thx harbor235
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harbor235Commented:
AAh, you did not say iBGP and I did not look to deeply into your configs and I assumed eBGP.  

good luck,

harbor235 ;}
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m1979Author Commented:
sorted
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