RE: BGP Cond Route Injection

From: Scott Morris (smorris@internetworkexpert.com)
Date: Wed Oct 22 2008 - 13:12:30 ARST


Glad it worked!
 
Scott

  _____

From: Dennis Worth [mailto:dennis.worth@gmail.com]
Sent: Wednesday, October 22, 2008 10:34 AM
To: smorris@internetworkexpert.com
Cc: Cisco certification
Subject: Re: BGP Cond Route Injection

Thanks Guys for the feedback.

I change the route-map to match on source which was pointed out.

That did the trick!

MAN! I looked at this stuff and read the DOCCD like 3 times, and still could
not see that error. I think I understand route Injection NOW!

The funniest thing about this was exactly that I was focused on the route
source from R5, and I had the next hop at first before I read the DOCCd, and
changed it to match the peering address which was stated.

RSRack1R3(config-route-map)#do sh ip bgp inj
BGP table version is 23, 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
* i150.1.8.0/24 167.1.58.8 0 ?
<-----YEAH!!!

Thank You all again!

On Wed, Oct 22, 2008 at 6:17 AM, Scott Morris
<smorris@internetworkexpert.com> wrote:

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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