[j-nsp] as-path rewrite

[Jaroslaw Adam Gralak]

On Tue, 2005-09-27 at 13:16 +0300, Sorin CONSTANTINESCU wrote:
> Hi, all.
> 
> I have the following topology:
> 
> AS1 - AS99 (L3 Mpls VPN) - AS2 - AS99 - INTERNET
> 
> My customer (AS2 - public AS Number) buys from the company i work for
> 2 services:
> 
> 1) Internet Access
> 2) VPN between his location, and AS1 (also public AS Number).
> 
> The problem i have is that when i receive a prefix originated by AS1
> on the Internet Transit BGP session, the AS-PATH is: 1 99 2 . Our
> network is a mixture of Juniper and Cisco routers. I used "allowas-in"
> on the neighbor to the customer, but the Juniper routers won't import
> this prefix throughout the network. I know i can use
> 
> a at R1# set loops ?
> Possible completions:
>   <loops>              Maximum number of times this AS can be in an AS
> path (1..10)
> [edit routing-options autonomous-system]
> a at R1# set loops
> 
> ... but i don't consider this an option.
> 
> Has anyone ever ran into this problem? As far as i see it, i have the
> following options:
> 
> - use private "local-as" for the BGP sessions between AS99 and AS1/AS2
> for the MPLS VPN BGP sessions (haven't tested this one so far)
> - ask the customer to configure EBGP Multihop between AS1 and AS2, so
> that my own AS won't be in the AS-PATH
> 
> I wish i could AS-PATH rewrite :))

You probably looking for:

as-override          Replace neighbor AS number with our AS number

Best regards,


-- 
Jaroslaw Adam Gralak
Technical University of Szczecin / Academic Center of Computer Science
JG1991-RIPE * http://www.man.szczecin.pl http://www.aci.com.pl