[c-nsp] PBR within MPLS VPN
Jeff Bacon
bacon at walleyesoftware.com
Tue Aug 28 20:17:54 EDT 2012
As I sit and write this, this starts to sound stupid even to me. Just stick with it, please, THEN tell me I'm being stupid. :)
So, device A is a cat6500/sup720, global IP 172.31.1.1/32, a PE device in an MPLS mesh. device B is a cat6500/sup720, global IP 172.31.1.14/32, PE device in another city. there is a VRF "fred" defined. There's device C, also with VRF fred, global IP 172.31.2.3/32, publishing a default route.
host1 (172.30.250.40) -> int vlan 49/vrf-fred/device-A <-> MPLS mesh <-> int g3/1/vrf-fred/device-B -> <INTERNET>
|
-> device-C-publishing-default-route -> <OTHERINTERNET>
so, the route table in VRF fred on device A looks like:
C 172.31.250.32 is directly connected, Vlan49 <---- host1 is here
200.3.3.0/24 is variably subnetted, 3 subnets, 3 masks
B 200.3.3.32/29 [200/0] via 172.31.1.14, 3d18h
B* 0.0.0.0/0 [20/8192] via 64.1.1.1, 5d23h
now, please don't ask why, but I want to be able to policy-route host1's traffic to make it use device-B and not follow the default route, e.g.:
int vlan 49
ip policy route-map source-route-map
route-map source-route-map permit 10
match ip address ACL-matching-172.30.250.40/32
set ip next-hop <something-making-it-go-to-B>
I have no idea what <something> should be.
Now, I can do "set ip next-hop recursive X" where X is a real IP in VRF fred on device B. Works fine. It's also software-switched - fast-path, "show ip cef switching stat feat" increments showing PBR is working via CEF, but "show int vlan49 switching" tells me that the packets are being fast-path-switched, not hardware-switched.
Release notes say that "set ip next-hop" is supported in hardware. But that presumes I give it the right IP address.
The problem is this: so what's the next-hop that I *can* use to specify CEF adjacency of "that specific other PE device over there, VRF fred"? It doesn't appear to be 172.31.1.14.
Or can you not policy-route to a non-directly-connected PE over MPLS using PBR?
(I can hear it now - "that's what TE is for" or "can't you split the traffic into separate VRFs and use source selection"... ok, yes, well... )
Thanks for your indulgence,
-bacon
More information about the cisco-nsp
mailing list