using static route with TE tunnel

garry-baker · ‎02-28-2008

Hi Guys,

I am having some difficulty getting traffic into a TE tunnel using static routes.

the architecture is PE to PE via ethernet. i have a single route that comes in via a subinterface which is in a vrf, when i put in a static route i get no traffic coming back. if i use the auto-route announce feature everything works, but i only want this vrf to go down the tunnel. the config on one end is as follows:

interface Tunnel1

ip unnumbered Loopback0

mpls ip

tunnel destination x.x.x.x

tunnel mode mpls traffic-eng

tunnel mpls traffic-eng priority 7 7

tunnel mpls traffic-eng bandwidth 1500

tunnel mpls traffic-eng path-option 10 dynamic

!

interface GigabitEthernet0/1.100

encapsulation dot1Q 100

ip vrf forwarding CCPUB

ip address 172.x.x.x 255.255.255.0

!

ip route 172.22.188.0 255.255.255.0 Tunnel1

ip route 172.22.192.0 255.255.255.0 Tunnel1

any suggestions?

Garry

arun kumar · ‎02-28-2008

Hi Garry,

You can chk this post for routing a specific VRF via TE tunnel:

http://forum.cisco.com/eforum/servlet/NetProf?page=netprof&forum=Service%20Providers&topic=MPLS&CommCmd=MB%3Fcmd%3Ddisplay_location%26location%3D.2cbf4822

Harold Ritter · ‎03-07-2008

Gary,

Are 172.22.188.0/24 and 172.22.192.0/24 VRF routes or BGP NH for the PEs advertising the VRF routes via BGP VPNv4? It should be the latter.

Hope this helps,

Harold Ritter
Sr Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México
Paseo de la Reforma 222
Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México

mheusing · ‎03-12-2008

Hi Harold,

As the routes are /24 it will not work in either case.

If the routes are for BGP next hops they must be /32 and if they are within the VRF this will lead to packet leaking.

This means, the VPN label will not be attached and thus no connectivity within the VRF will be achieved.

This goes back to one of our discussions here in 2005:

http://forum.cisco.com/eforum/servlet/NetProf?page=netprof&forum=Service%20Providers&topic=MPLS&CommCmd=MB%3Fcmd%3Ddisplay_location%26location%3D.1dda007d

Regards, Martin

Harold Ritter · ‎03-13-2008

Martin,

There is nothing that would prevent the BGP NH for VPNv4 routes to resolve via a /24 static route pointing at a tunnel interface, such as the ones posted by the original poster.

The fact that the BGP NH should be resolved via a /32 is rather a recommendation/best practices rather than a hard limitation.

Regards,

Harold Ritter
Sr Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México
Paseo de la Reforma 222
Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México

mheusing · ‎03-14-2008

Hi Harold,

this would only work, if the Loopback is configured as /24, otherwise the LIB would not contain a suitable entry and hence no label could be found. This is what I meant, but did not express to clearly.

Regards, Martin

Harold Ritter · ‎03-14-2008

Martin,

I was assuming TE LSP from ingress to egress PE. The LIB would not be used at all in this case.

You would still certainly need the loopback interface at the other end to be advertised as a /24 or greater for it to be overridden by the /24 static route pointing at the tunnel interface.

Regards,

Harold Ritter
Sr Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México
Paseo de la Reforma 222
Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México

mheusing · ‎03-14-2008

Hi Harold,

As "mpls ip" is configured on the tunnel interface would the LIB be in the picture then?

Regards, Martin