[c-nsp] Filtering BGP routes with route-map vs. not getting them in

[OCOSA ListAcct]

Mike,

I am not understanding what you are asking here? Explain please....

Prepending would only give Kris a longer as path...making others prefer 
Kris shorter path over that one. I believe his goal is to get full 
routes and do what he pleases. But use all 120,000 once he gets a bigger 
router. I think it's 120,000 maybe more or less.

Actually if Kris' upstream did communities with him he could get 
customers routes and default that way....much cleaner I think....

Otis



Michael K. Smith - Adhost wrote:
> For customer only routes wouldn't this be better to account for
> prepending?
>
> Ip as-path access-list 5 permit ^(providerAS_)+([0-9_])+$
>
> Regards,
>
> Mike
>
>   
>> -----Original Message-----
>> From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp-
>> bounces at puck.nether.net] On Behalf Of OCOSA ListAcct
>> Sent: Friday, July 06, 2007 12:03 PM
>> To: Kristian Kielhofner
>> Cc: cisco-nsp at puck.nether.net
>> Subject: Re: [c-nsp] Filtering BGP routes with route-map vs. not
>> getting them in
>>
>> True if really want to use option b...
>>
>> use this string to get routes directly connected to your upstream or
>> originated.
>>
>> ip as-path access-list 5 permit ^upstream as goes here_[0-9]*$
>>
>> or
>>
>>
>> to deny any networks originated form your upstream...and allows
>> everything else which could be bad if your router does not have at
>> least
>> 512MB
>>
>> ip as-path access-list 6 deny _upstream as goes here$
>> ip as-path access-list 6 permit .*
>>
>>
>> If I remember correctly you can also limited the amount of prefixes a
>> neighbor can send you...
>>
>> router bgp as number
>> nei x.x.x.x maximum-prefixes and the rest....
>>
>> I think the command is
>>
>>
>> Otis
>>
>> Kristian Kielhofner wrote:
>>     
>>> Hello everyone,
>>>
>>>   I'm back with another stupid "BGP on a 3750" question.  I need
>>> "customer only routes" to the few providers that I have.  From what
>>>       
> I
>   
>>> can tell, I'd end up with far less than the 8,000 max routes this
>>> platform can handle.  I have two options when configuring this:
>>>
>>> a)  When bringing up the BGP session, I can request aggregated
>>> customer-only routes (what I want).
>>>
>>> or...
>>>
>>> b)  I can request a full table and filter them myself with route-map
>>> statements (I think).
>>>
>>>   With "a" I will have a much simpler configuration (not that it
>>> matters much).  Will the 3750 have problems even receiving these
>>> routes, even if I am filtering them?  I can imagine all sorts of
>>> potential nastiness with that configuration.
>>>
>>>   If not, I'd much rather go with option "b".  I would have more
>>> control over my routing and it would be easier to upgrade to a more
>>> capable router in the future (less co-ordination with ISPs, just
>>> remove route-map statements).  I like this idea more.  Can the 3750
>>>       
>> do
>>     
>>> it?  What would happen?
>>>
>>> Thanks!
>>>
>>>
>>>       
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