[c-nsp] GRE tunnel routes not making it into FIB - 2911/K9

[Harold Ritter (hritter)]

Hi Tim,

The fact that you are seeing the physical interface (gig0/0) is normal, as
it is the recursive adjacency and ultimately the interface through which
will exit the box. You can do a "show ip cef 0.0.0.0 0.0.0.0 int" if you
want to see more details about the recursion. The issue is somewhere else.

Regards





Le 2013-09-07 14:17, « Tim Huffman » <tim at bobbroadband.com> a écrit :

>I have a customer with a strange problem that I can duplicate on a
>similar set up. We are both using Cisco 2911 routers. His is running
>version 15.1(4)M5 (base license), and mine is running 15.0(1)M6.
>
>What's happening is this: There is a GRE tunnel set up between his router
>(a 2911) and mine (a 6503/sup720). We are running BGP over that GRE
>tunnel. The tunnel is up, and the two routers can pass traffic through
>the tunnel, but only to the router interfaces, NOT to devices on the
>customer LAN. On the 6503 side, the routes are installed normally, and
>CEF shows that traffic destined for his LAN should be going over the
>tunnel.
>
>However, on the 2911 side, although the tunnel is up, and BGP is working,
>traffic is not being encapsulated, and devices attached to his LAN cannot
>get out to the Internet. When I do a 'sh ip route' things look fine. If I
>do a 'sh ip cef' things look fine. But if I do a 'sh ip cef exact-route'
>things get weird.
>
>Here's what I'm seeing on his router:
>
>#sh ip route
>...
>B*    0.0.0.0/0 [1/0] via 10.254.20.25
>
>#sh ip cef
>Prefix               Next Hop             Interface
>0.0.0.0/0            10.254.20.25         Tunnel5
>
>Everything looks good. Here's where it gets weird:
>
>#sh ip cef exact-route 199.195.246.10 63.250.224.22
>199.195.246.10 -> 63.250.224.22 => IP adj out of GigabitEthernet0/0, addr
>63.250.226.93
>
>Even if I take out the BGP route, and try STATICALLY routing traffic over
>the connection, I get similar results:
>#sh ip route
>...
>S*    0.0.0.0/0 [1/0] via 10.254.20.25
>
>#sh ip cef exact-route 199.195.246.10 63.250.224.50
>199.195.246.10 -> 63.250.224.50 => IP adj out of GigabitEthernet0/0, addr
>63.250.226.93
>
>Is there something I'm missing? Could this be an IOS bug? Both 2911s are
>running the 'base' license, is routing over simple GRE something that's
>only enabled on some other license?
>
>--
>Tim Huffman
>
>
>_______________________________________________
>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/