problem with BGP or I am an Idiot

Fri Nov 17 15:45:52 UTC 2006

On Nov 17, 2006, at 9:57 AM, Bruce Pinsky wrote:

>> Probabaly the the latter; however here is the situation. I am  
>> advertising a rte 1.1.1.1 via BGP to the Internet via ISP_A via my  
>> location in NJ. At my other location in CA where I am advertising  
>> another rte 2.2.2.2 via BGP to the Internet via the same ISP_A. I  
>> am using the same AS for both routes.
>>
>> For some reason on my rtr advertising the 2.2.2.2 rte I am unable  
>> to see the 1.1.1.1 rte "% Network not in table". I know 1.1.1.1  
>> rte is valid it shows up in looking glass and ISP_A has it on the  
>> peer 2.2.2.2 recevies full Internet rtes from. Further  
>> verification: I add a static rte on 2.2.2.2 rtr to 1.1.1.1 and its  
>> routable???
>>
>> How is this possible? I have the following filters but I removed  
>> them and it seems to not make a diff.
>> OUTBOUND - ip as-path access-list 1 permit ^$
>>                      ip as-path access-list 1 deny .*
>> INBOUND - ip as-path access-list 2 permit .*
>
> Loop protection.  Throw away any route I hear from someone else  
> with my AS.

As long as you are hearing default your transit providers (you do  
have at least two, right? if you only have one, you don't need BGP  
and are just polluting the routing table), it won't matter if you can  
hear the prefix from your other location.

-- 
TTFN,
patrick