Facing problem while redistributing RIP routes in BGP

[Nikhil Srivastava]

  Hi All,

we are facing some problems while redistributing the RIP routes into BGP.

Scenario is like we are using RIP between My site and client router and we are redistributing some of the routes learned via RIP into the BGP ( we are using BGP to take clients routes inside our network)

We are using a route-Map in which we have allowed the rip routes that we want to install in our bgp table,but the problem is we are not able to install only one subnet out of many that we have allowed in the access-list , all the routes that we have allowed in ACL are there in the routing table,for the workaround we have advertise this subnet by using the network command in bgp and now we can see the routes in the BGP table.

can anyone help me out on this why we are not able to see only one subnet in our BGP table by using the redistribution.

[Vinayaka Raman]

If X is the subnet ID  in question( not redistributed from RIP into BGP) and Y is the mask.. Please furnish following details

show ip route X Y

show ip bgp X Y

show ip rip database X Y

[Nikhil Srivastava]

hi, please find the same

sh ip route 199.67.210.0 255.255.255.0

Routing entry for 199.67.210.0/24

  Known via "rip", distance 120, metric 1

  Redistributing via bgp 65533, rip

  Advertised by bgp 65533 metric 100 route-map RIP-BGP

  Last update from 169.189.164.185 on GigabitEthernet0/0, 00:00:27 ago

  Routing Descriptor Blocks:

  * 169.189.164.185, from 169.189.164.185, 00:00:27 ago, via GigabitEthernet0/0

      Route metric is 1, traffic share count is 1

=============================

sh ip bgp 199.67.210.0 255.255.255.0

BGP routing table entry for 199.67.210.0/24, version 1456

Paths: (1 available, best #1, table Default-IP-Routing-Table)

  Advertised to update-groups:

     1

  Local

    169.189.164.185 from 0.0.0.0 (169.189.164.187)

      Origin IGP, metric 1, localpref 100, weight 32768, valid, sourced, local, best

WBPO-Southwest-RTR#

=========================================

sh ip rip database 199.67.210.0 255.255.255.0

199.67.210.0/24

    [1] via 169.189.164.185, 00:00:09, GigabitEthernet0/0 sh ip rip database 199.67.210.0 255.255.255.0
199.67.210.0/24
    [1] via 169.189.164.185, 00:00:09, GigabitEthernet0/0

====================================

we have removed the enrty from the ACL because we are not able to see the entry for this in bgp table despite allowing this in the acl.

[Vinayaka Raman]

We need the following commands when the workaround is not in place to understand what exactly is happening..
Is it possible to remove the network statement, permit in the ACL and then get

show ip route X Y
show ip bgp X Y

Let's say we have a prefix x in the routing table and we try to redistribute it into bgp table (provided you allow the exact match in redistribution ACL) then we should see then. Now, the question would be if bgp is advertising the prefix to its neighbour....? Show ip bgp at that circumstance will answer it..

Sent from Cisco Technical Support iPad App

[Vinayaka Raman]

Another question:

"for the workaround we have advertise this subnet by using the network command in bgp and now we can see the routes in the BGP table."

router bgp 65533

no synchronization

bgp log-neighbor-changes

network 199.67.210.0

redistribute rip metric 100 route-map RIP-BGP

Assuming 199.67.210.0 is added as work around.

I do not see 199.67.210.0 allowed in the ACL..

[Shirshendu Nandi]

If you are doing this

network 199.67.210.0

Then you dont need to redistribution

belive you have synchonisation disabled

[Nikhil Srivastava]

hi Nandi,

yes if we using the network command then we didnt need to use the redistribution ,but we are using this network command because we are not able to redistribute this ,thats wat the issue is.

and yes synchronization is disabled.

[Shirshendu Nandi]

Are You using RIP v1 or V 2

Also can i have the ourput of your route-map and assiciated ACL that is configured. Must be some Hidden magic there itself

[Nikhil Srivastava]

RIP V2

[Shirshendu Nandi]

I do not see the subnet 199.67.210.0 255.255.255.0 is allowed in your below ACL . Pls apermit the subnets of RIP routes in this ACL

Pls see the below as you have given output there is no segment for 199 network allowed .

   10 permit 169.173.0.0, wildcard bits 0.0.255.255 (43 matches)

    20 permit 169.185.0.0, wildcard bits 0.0.255.255 (43 matches)

    30 permit 165.203.0.0, wildcard bits 0.0.255.255 (43 matches)

    40 permit 159.17.0.0, wildcard bits 0.0.255.255 (43 matches)

    50 permit 135.155.0.0, wildcard bits 0.0.255.255 (41 matches)

    60 permit 208.238.11.144, wildcard bits 0.0.0.15 (53 matches)

    70 permit 169.193.0.0, wildcard bits 0.0.255.255 (39 matches)

    80 permit 169.171.0.0, wildcard bits 0.0.255.255 (39 matches)

    90 permit 153.40.0.0, wildcard bits 0.0.255.255 (39 matches)

    100 permit 150.110.0.0, wildcard bits 0.0.255.255 (37 matches)

    110 permit 162.124.0.0, wildcard bits 0.0.255.255 (37 matches)

    120 permit 10.42.0.0, wildcard bits 0.0.255.255 (8 matches)

[Nikhil Srivastava]

dear nandi,

we have removed it from the ACL because we are not able to redistribut only this subnet in our BGP, we are only able to take it in our bgp table only when we have applied the network command for this particular subnet.

[Shirshendu Nandi]

This is something strange if you remve the entire ACL and try only redistribute rip metric 100 then whats happening?

remove the network command when you try this .you would like to troubleshoot is it the route map or the ACL whch is malfunctioning .

[Nikhil Srivastava]

i dont think we can do this as  unnecessary flooding of unwanted subnets will happen in our network beacuse of this which we dont want.

however we have try by removing the redistributin command and then reapply it but still we didnt get the succuss and we have to go for the workaround and add that netwrok command in the bgp

[Shirshendu Nandi]

Ok If you dont have Much of a choice to troubleshoot  you are more aware of your network about its pros and cons of applying any command.

Thanks anyways its was great interracting and sorry i could not be much of any help to this issue .

[paul driver]

Hello,

You are not clear regards  the peering of bgp ( EBGP or IBGP)

If you are trying to install routes from bgp into an IGP like rip, bgp will only allow ebgp learned routes to be advertised, Trying to install IGBP routes into IGP (rip) is not allowed by default.

To allow ibgp routes into igp process like rip you after use the bgp redistribute-internal command under bgp

On a side note, I can see that bgp is auto summarising- have you applied  no auto-summaryunder bgp process to advertise the more specific routes

res

Paul