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New Member

mGRE-mGRE tunnels with static routes

I have a bunch of 172.15.0.X /29 networks (17 at present time) that I want to interconnect in a full-meshed fashion using mGRE. As an edge devices I have Cisco851 routers. From various sources I gathered that I have to use VRF so that the tunnel knows where to send encapsulated data. And this is where my confusion starts. Here is what I do:

ip vrf tstvrf

rd 1:1

interface Tunnel10

ip vrf forwarding tstvrf

ip address

no ip redirects

keepalive 1 100

tunnel source FastEthernet4

tunnel mode gre multipoint

tunnel key 123

interface FastEthernet4

ip address

no ip redirects

no ip unreachables

no ip proxy-arp

duplex auto

speed auto

ip route vrf tstvrf Tunnel10 global

ip route ! next hop gateway

Where is the address of another Cisco851 that also terminates mGRE.

ping sou

Sending 5, 100-byte ICMP Echos to, timeout is 2 seconds:

Packet sent with a source address of


Tunnels do not work except for the case when I use pair mGRE-GRE. Here I see only one-way data flow from GRE to mGRE.

Some of the examples show mGRE with nhrp others with BGP4. Cisco851 have nether of them and tend to use static routes for the starters.

How can you help me?

New Member

Re: mGRE-mGRE tunnels with static routes

New fw (c850-advsecurityk9-mz.124-15.T1) has nhrt for mGRE so the problem is solved.