[c-nsp] BGP/private and public ASN mix trick

[David Prall]

64001 is not a Private AS, you need to use 64512 to 65535. Then use
remove-private-as on external connections.

David

--
http://dcp.dcptech.com
  

> -----Original Message-----
> From: cisco-nsp-bounces at puck.nether.net 
> [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Nick Kraal
> Sent: Saturday, August 25, 2007 10:38 AM
> To: cisco-nsp at puck.nether.net
> Subject: [c-nsp] BGP/private and public ASN mix trick
> 
> Dear all,
> 
> I have a tricky/creative arrangement here to provide to a customer.
> 
> [1] The customer has their own prefixes [a.b.c.d/20], but no ASN.
> [2] We plan to run private BGP with the customer to receive this
>      prefix, and for us to announce the global routing table.
> [3] Objective is to then announce this prefix as originating 
> from AS111
>      to all AS111 public BGP peers.
> [4] Sample configuration at the end of this e-mail. Any 
> potential traps
>      here?
> [5] Prefix list [TUN-CUST-CIDR-BLOCK] is then used in route-maps with
>      other BGP peers. Are removing private-as and the inbound 
> route-map
>      sufficient for BGP to pick this prefix up and announce 
> it as AS111?
> 
> Thanks in advance,
> 
> -nick/
> ======================
> Current configuration:
> 
> router bgp 111
>   neighbor 200.100.1.10 remote-as 64001
> !
> address-family ipv4
> neighbor 203.100.1.10 activate
> neighbor 203.100.1.10 next-hop-self
> neighbor 203.100.1.10 remove-private-as
> neighbor 200.100.1.10 soft-reconfiguration inbound
> neighbor 200.100.1.10 route-map TUN-CUST-FILTER-IN in
> neighbor 200.100.1.10 route-map TUN-CUST-FILTER-OUT out
> !
> route-map TUN-CUST-FILTER-IN permit 5
>   match ip address TUN-CUST-CIDR-BLOCK
>   set origin igp
> !
> route-map TUN-CUST-FILTER-OUT permit 10
>   match as-path 75
> !
> ip prefix-list TUN-CUST-CIDR-BLOCK seq 5 permit a.b.c.d/20
> 
> _______________________________________________
> cisco-nsp mailing list  cisco-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/
>