[c-nsp] tag-switching advertise-tags for?

Jon Lewis jlewis at lewis.org
Tue Oct 25 10:12:01 EDT 2005


On Tue, 25 Oct 2005, Aamer Akhter (aakhter) wrote:

> Just to clarify, there is a way to have single session which shares ipv4 
> + vpnv4 and a relatively simple config.
>
> You'll need to have 2 loopbacks: one for ipv4 another for vpnv4. 
> Additionally, you'll need one route-map: to change the next-hop to one 
> of the loopbacks per address-family. The other loopback will be set by 
> default.

Actually, I think making changes to BGP is the wrong track.  The routes in 
question are not in our iBGP.  They're being learned via OSPF.

More puzzling, if I
sh [mpls|tag-switching] forwarding-table [prefix of customer's voip server]
on what I called RouterO (the core side of our network, the customer 
connects to RouterL), the result is:

Local  Outgoing    Prefix              Bytes tag  Outgoing   Next Hop
tag    tag or VC   or Tunnel Id        switched   interface
719    Untagged    [custprefix/mask]   0          Se5/0/2:0  point2point

Se5/0/2:0 is the right interface according to the static route I put in 
place to try to get this customer's voip traffic onto a dedicated circuit 
from RouterO to RouterL.

But when I ping flood their prefix from various servers on our network, 
none of the packets actually ride Se5/0/2:0 (at least not according to O's 
output counter, or L's input counter).

Other prefixes destined for RouterL, learned on RouterO via OSPF have both 
local and outgoing tags and the above command shows that they'll ride the 
multiple T1's between O and L, and that lots of bytes have been switched 
to each of those T1's.

----------------------------------------------------------------------
  Jon Lewis                   |  I route
  Senior Network Engineer     |  therefore you are
  Atlantic Net                | 
_________ http://www.lewis.org/~jlewis/pgp for PGP public key_________


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