[j-nsp] Maximum AS PATH length

[Harry Reynolds]

>From a recent thread ion this subject:

"You should be able to use something a bit simpler:

	as-path morethan50 ".{51,}";

and it will likely have a lot less overhead in the internal RegEx
processing!"


 Cheers


> -----Original Message-----
> From: juniper-nsp-bounces at puck.nether.net 
> [mailto:juniper-nsp-bounces at puck.nether.net] On Behalf Of 
> Kevin Epperson
> Sent: Thursday, February 17, 2005 7:30 AM
> To: Edwin Lok
> Cc: juniper-nsp at puck.nether.net
> Subject: Re: [j-nsp] Maximum AS PATH length
> 
> I believe juniper was working on a specific knob similiar to 
> cisco...not sure what code that is/was introduced in or details.
> 
> In leiu of that you could build an as-path filter that wild 
> card matchs a path of X or more and filter it out as you 
> would martians and other bad things.
> 
> It would likely look something like this to filter 25+ AS path length:
> 
>  as-path long-path ". . . . . . . . . . . . . . . . . . . . . 
> . . . .*"
> 
> 	-Kevin
> 
> On Thu, 17 Feb 2005, Edwin Lok wrote:
> 
> > Hi,
> >
> > Recently that was a case of an exceptionally long ASPATH being 
> > advertised in the internet.
> >
> > Jan 30 18:34:51 EST: %BGP-6-ASPATH: Long AS path 6461 3356 
> 6770 8282 
> > 8282
> > 8282 8282 8282 8282 8282 8282 8282 8282 8282 8282 8282 8282 
> 8282 8282 
> > 8282
> > 8282 8282 8282 8282 8282 8282 8282 8282 8282 8282 8282 8282 
> 8282 8282 
> > 8282
> > 8282 8282 8282 8282 8282 8282 8282 8282 8282 8282 8282 8282 
> 8282 8282 
> > 8282
> > 8282 8282 8282 8282 8282 8282 8282 8282 8282 8282 8282 8282 
> 8282 8282 
> > 8282
> > 8282 8282 8282 8282 8282 8282 8282 8282 8282 8282 8282 8282 
> 8282 8282 
> > 8282
> > 8282 8282 8282 8282 8282 8282 8282 8282 8282 8282 8282 8282 
> 8282 8282 
> > 8282
> >
> > Cisco has a way to limit the maximum as-path received. Is there a 
> > similar command in Junos to do this? And will the router have any 
> > issue with this abnormally long AS PATH advertisements?
> >
> > Rgds
> > Edwin
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> >
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