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

[Oliver Boehmer (oboehmer)]

Jon Lewis <> wrote on Tuesday, October 25, 2005 4:12 PM:

> 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. 

Well, then your issue can be addressed by restricting label
advertisements to BGP next-hops (i.e. PE loopbacks)? Then your
OSPF-learnt routes won't be label-switched, voila.
 
> 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 
> 
> 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).

the LFIB entry above ("show mpls forwarding") means: *If* a packet comes
in with label 719, I pop all labels and send it untagged via S5/0/2:0.
Your node will still allocate a label (719 in this case) and sets up the
LFIB, but it won't advertise it if you limited the advertisement via
tag-sw advertise-tags for.. so the LFIB counters are only updated if
labelled traffic comes in.

The packets should show up on the interface counters, though.. If they
are not, something else is broken.

	oli