[afnog] AS filtering question

[Saul Stein]

Thanks guys!

-----Original Message-----
From: Mark Tinka [mailto:mark.tinka at seacom.mu] 
Sent: 05 September 2013 01:44 PM
To: Philip Smith
Cc: Nishal Goburdhan; Saul Stein; African Network Operators
Subject: Re: [afnog] AS filtering question

On Thursday, September 05, 2013 01:19:18 PM Philip Smith
wrote:

> I wished, nay, asked for many years that Cisco would add named as-path 
> filters, like we have named access-lists and prefix-lists. I still 
> have a v long wish list. :-(

They fixed that in IOS XR. Some examples:

as-path-set as-path-inbound-some-network
  ios-regex '^(65001_)+$'
end-set
!
as-path-set as-path-inbound-other-network
  ios-regex '^(65002_)+$'
end-set
!
as-path-set as-path-inbound-another-network
  ios-regex '^(65003_)+$',
  ios-regex '^(65003_)+(65004_)+$',
  ios-regex '^(65003_)+(65005_)+$',
  ios-regex '^(65003_)+(65006_)+$',
  ios-regex '^(65003_)+(65007_)+$'
end-set

> Got scars, but no good advice apart from keep it simple.
> I use off-line master config file, keep it well documented with 
> detailed comments about what each as-path filter does. Seems to work 
> for me, but then I'm v used to that process.

Agree - best way in IOS and IOS XE, to be honest.

Mark.