RE: BGP Cond Route Injection

From: Scott Morris (smorris@internetworkexpert.com)
Date: Wed Oct 22 2008 - 11:17:54 ARST


The idea behind the inject map is to bring in more specific prefixes about
what was learned.

You are matching one thing, and that must be in yout table (self-generated
or learned):

*>i150.1.0.0/20 167.1.58.8 0 100 0 65078 I

Then you match route-source.

ip prefix-list ROUTE-SOURCE seq 5 permit 167.1.135.5/32 !

Now, that peer address and the next-hop listed in BGP are different. That
MAY be ok, but I can't determine from what you put down below whether the
ROUTE-SOURCE (a listed neighbor command) matches up with where that next-hop
came from? Check out "show ip bgp 150.1.0.0".

Now, the next part. Your route-map. I have personally never tried putting
things on one line as you have there:

route-map LEARNED_PATH permit 10
 match ip address prefix-list EXITSING_ROUTE ROUTE-SOURCE !

I'd try:

route-map LEARNED_PATH permit 10
 match ip address prefix-list EXITSING_ROUTE
 match ip route-source prefix-list ROUTE-SOURCE

And see where you go from there. As long as your injected route
(Prefix-List SW2_LOOP) is a subset of the original routes (which it is) then
you should do just fine.

Don't forget to verify with "show ip bgp inject"

HTH,

Scott Morris, CCIE4 #4713, JNCIE-M #153, JNCIS-ER, CISSP, et al.
CCSI/JNCI-M/JNCI-ER
Senior CCIE Instructor

smorris@internetworkexpert.com

 

Knowledge is power.
Power corrupts.
Study hard and be Eeeeviiiil......

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Dennis Worth
Sent: Wednesday, October 22, 2008 1:47 AM
To: Cisco certification
Subject: BGP Cond Route Injection

I have spent the last 2 hours fumbling with this configure and understand
it. Any help figuring out what I've done wrong would be awesome.

Here are my configs.

RSRack1R3(config-router)#do sh ip bgp
BGP table version is 18, local router ID is 150.1.3.3 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
*> 28.119.16.0/24 204.12.1.254 0 0 54 i
* i 204.12.1.254 0 100 0 54 i
* i 150.1.6.6 0 100 0 54 i
*> 28.119.17.0/24 204.12.1.254 0 0 54 i
* i 204.12.1.254 0 100 0 54 i
* i 150.1.6.6 0 100 0 54 i
*> 112.0.0.0 204.12.1.254 0 54 50 60 i
* i 204.12.1.254 0 100 0 54 50 60 i
* i 150.1.6.6 0 100 0 54 50 60 i
*> 113.0.0.0 204.12.1.254 0 54 50 60 i
* i 204.12.1.254 0 100 0 54 50 60 i
* i 150.1.6.6 0 100 0 54 50 60 i
*> 114.0.0.0 204.12.1.254 0 54 i
* i 204.12.1.254 0 100 0 54 i
* i 150.1.6.6 0 100 0 54 i
*> 115.0.0.0 204.12.1.254 0 54 i
* i 204.12.1.254 0 100 0 54 i
   Network Next Hop Metric LocPrf Weight Path
* i 150.1.6.6 0 100 0 54 i
*> 116.0.0.0 204.12.1.254 0 54 i
* i 204.12.1.254 0 100 0 54 i
* i 150.1.6.6 0 100 0 54 i
*> 117.0.0.0 204.12.1.254 0 54 i
* i 204.12.1.254 0 100 0 54 i
* i 150.1.6.6 0 100 0 54 i
*> 118.0.0.0 204.12.1.254 0 54 i
* i 204.12.1.254 0 100 0 54 i
* i 150.1.6.6 0 100 0 54 i
*> 119.0.0.0 204.12.1.254 0 54 i
* i 204.12.1.254 0 100 0 54 i
* i 150.1.6.6 0 100 0 54 i
*>i150.1.0.0/20 167.1.58.8 0 100 0 65078 i
r>i167.1.4.0/24 150.1.4.4 0 100 0 i
*>i167.1.5.0/24 167.1.135.5 0 100 0 i
*>i205.90.31.0 192.10.1.254 0 100 0 254 ?
*>i220.20.3.0 192.10.1.254 0 100 0 254 ?
*>i222.22.2.0 192.10.1.254 0 100 0 254 ?

RSRack1R3(config-router)# do sh run | b router bgp
router bgp 100
 no synchronization
 bgp log-neighbor-changes
 bgp inject-map ORIGINATE exist-map LEARNED_PATH
 neighbor AS-100-PEER peer-group
 neighbor AS-100-PEER remote-as 100
 neighbor AS-100-PEER update-source Loopback0
 neighbor AS-100-PEER route-reflector-client
 neighbor AS-100-PEER next-hop-self
 neighbor AS-100-PEER send-community
 neighbor AS-100-PEER route-map TO_IBGP_PEERS out
 neighbor 150.1.1.1 peer-group AS-100-PEER
 neighbor 150.1.4.4 peer-group AS-100-PEER
 neighbor 150.1.6.6 peer-group AS-100-PEER
 neighbor 150.1.9.9 peer-group AS-100-PEER
 neighbor 150.1.9.9 shutdown
 neighbor 150.1.10.10 peer-group AS-100-PEER
 neighbor 150.1.10.10 shutdown
 neighbor 167.1.135.5 peer-group AS-100-PEER
 neighbor 204.12.1.254 remote-as 54
 neighbor 204.12.1.254 remove-private-AS
 neighbor 204.12.1.254 route-map PREPEND out
 no auto-summary !
ip classless
!
ip http server
no ip http secure-server
!
!
ip prefix-list EXITSING_ROUTE seq 5 permit 150.1.0.0/20 !
ip prefix-list ROUTE-SOURCE seq 5 permit 167.1.135.5/32 !
ip prefix-list SPECIFIC-ROUTE seq 5 permit 150.1.8.0/24 !
ip prefix-list SW2_LOOP seq 5 permit 150.1.8.0/24 !
ip prefix-list VLAN_4_and_VLAN_5 seq 5 permit 167.1.4.0/24 ip prefix-list
VLAN_4_and_VLAN_5 seq 10 permit 167.1.5.0/24 !
route-map LEARNED_PATH permit 10
 match ip address prefix-list EXITSING_ROUTE ROUTE-SOURCE !
route-map ORIGINATE permit 10
 set ip address prefix-list SW2_LOOP
!
route-map TO_IBGP_PEERS deny 10
 match ip address prefix-list SPECIFIC-ROUTE !
route-map TO_IBGP_PEERS permit 1000
!
route-map PREPEND permit 10
 match ip address prefix-list VLAN_4_and_VLAN_5 set as-path prepend 100 100
!
route-map PREPEND permit 1000

RSRack1R3#sh ip bgp injected-paths
>>>>BLANK<<<<

Maybe I'm just tired!

--
Dennis Worth

Blogs and organic groups at http://www.ccie.net



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