From: Jack Heney (jheneyccie@xxxxxxxxxxx)
Date: Tue Nov 07 2000 - 18:10:01 GMT-3
Another experiment that might make this more clear is instead of trying to
permit or deny routes, send an IBGP peer to routes using BGP and on the
peer, try to change the local preference of just one of the routes using an
inbound route-map and match ip address. You'll find that no matter what you
do, both routes will always get the same local preference.
>From: "Jack Heney" <jheneyccie@hotmail.com>
>Reply-To: "Jack Heney" <jheneyccie@hotmail.com>
>To: sam@munzani.com, Steve.McNutt@ahlcorp.com, ejastak@gobosh.cc
>CC: ccielab@groupstudy.com
>Subject: Re: BGP Route-maps
>Date: Tue, 07 Nov 2000 20:42:25 GMT
>
>I had the same experience as Steve....It appears to me that this rule only
>applies to IBGP...Here's what I did:
>
>R1-------------R2--------------R3-------------
> 10.4.2.0/24 10.4.1.0/24
>
>I put R1 in BGP AS 1 and R2 and R3 in BGP AS 2
>R3 is injecting both attached networks into BGP
>R2 has synchronization disabled
>
>First, I created the following route-map on R2 and applied it inbound to R3
>(ibgp):
>route-map cisco deny 10
> match ip address 1
>route-map cisco permit 20
>
>access-list 1 permit 10.4.1.0 0.0.0.255
>
>I expected to see only 10.4.1.0/24 denied, but instead both routes were
>denied...It appears that the router ignored the match statement (because it
>referenced an IP address) and becuase there was no other match statement,
>both routes matched the first clause and were denied.
>
>Then, I removed this route-map from R2 and created the exect same route-map
>on R1 and applied it inbound to R2 (ebgp). R1 learned about the
>10.4.2.0/24
>network, but not the 10.4.1.0/24 network. When I debug bgp in and debug
>bgp
>update, the router indicates that the route-map has filtered the
>10.4.1.0/24
>route.
>
>I think this is a pretty simple yet effective experiment, and I would love
>to know what somebody else sees if they replicate it (maybe I'm missing
>something).
>Jack
>>From: "Sam Munzani" <sam@munzani.com>
>>Reply-To: "Sam Munzani" <sam@munzani.com>
>>To: "McNutt, Steve" <Steve.McNutt@ahlcorp.com>, "'Eric Jastak'"
>><ejastak@gobosh.cc>
>>CC: <ccielab@groupstudy.com>
>>Subject: Re: BGP Route-maps
>>Date: Tue, 7 Nov 2000 13:53:36 -0600
>>
>>Not really. Here is my configs and bgp table.
>>
>>First is with route-map with filters. Then I removed route-map with filter
>>and you will see 192.168.1.0/24 in bgp table.
>>
>>Config with route-map inbound filters:
>>router bgp 1
>>
>>no synchronization
>>
>>bgp log-neighbor-changes
>>
>>neighbor 132.5.5.5 remote-as 1
>>
>>neighbor 132.5.5.5 update-source Loopback9
>>
>>neighbor 132.5.5.5 route-map inbound in
>>
>>neighbor 132.5.6.6 remote-as 1
>>
>>neighbor 132.5.6.6 update-source Loopback9
>>
>>neighbor 132.5.6.6 route-map inbound in
>>
>>neighbor 132.5.129.2 remote-as 4
>>
>>!
>>
>>!
>>
>>access-list 99 deny 192.168.1.0 0.0.0.255
>>
>>access-list 99 permit any
>>
>>route-map inbound permit 10
>>
>>match ip address 99
>>
>>
>>Config without Route-map inbound filters:
>>
>>router bgp 1
>>
>>no synchronization
>>
>>bgp log-neighbor-changes
>>
>>neighbor 132.5.5.5 remote-as 1
>>
>>neighbor 132.5.5.5 update-source Loopback9
>>
>>neighbor 132.5.6.6 remote-as 1
>>
>>neighbor 132.5.6.6 update-source Loopback9
>>
>>neighbor 132.5.129.2 remote-as 4
>>
>>Just do like this and you will see the results
>>
>>Sam
>>
>> ----- Original Message -----
>> From: McNutt, Steve
>> To: 'Eric Jastak' ; 'Sam Munzani'
>> Cc: 'ccielab@groupstudy.com'
>> Sent: Tuesday, November 07, 2000 1:43 PM
>> Subject: RE: BGP Route-maps
>>
>>
>> I can confirm that the rule does apply to IBGP. I ran into this last
>>night on CCBootcamp lab 12. The rule makes sense given the goal of IBGP
>>is to maintain AS consistancy.
>>
>> Lab 12 is cool because it gave me an idea of how confusing things can
>>get when working with confederations. The scoping of some rules are
>>changed, but some are not, and the confederation makes it harder to tell
>>if
>>you are not meeting an AS wide "IBGP" type rule.
>>
>> -----Original Message-----
>> From: Eric Jastak [mailto:ejastak@gobosh.cc]
>> Sent: Tuesday, November 07, 2000 2:14 PM
>> To: 'Sam Munzani'
>> Cc: 'ccielab@groupstudy.com'
>> Subject: RE: BGP Route-maps
>>
>>
>> I think that rule only applies to iBGP. Was the route-map applied to
>>an iBGP or eBGP neighbor?
>>
>> - Eric
>> -----Original Message-----
>> From: Sam Munzani [mailto:sam@munzani.com]
>> Sent: Tuesday, November 07, 2000 10:07 AM
>> To: ccielab@groupstudy.com
>> Subject: BGP Route-maps
>>
>>
>> Hi Group,
>>
>> As everybody might have read it in Halabi and bunch of other
>>sources.
>> "Inbound Route-map does not work when used with matching IP
>>address". Today I experimented and it works inbound also. Violating the
>>BGP
>>(or Halabi) rule for route-maps.
>>
>> Sam
>
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