[Xorp-users] OSPF Over GRE Tunnel using XORP

[Bruce M Simpson]

Olivier BONHOMME wrote:
> I tried to set up a XORP configuration but the Hello Messages are not 
> sent in the GRE tunnel and my tunnel interface didn't join the 224.0.0.5 
> group.
>
> I would like to know if a such architecture (OSPF over GRE) is possible 
> and if there is a specific clue in XORP configuration to do this ?
>   

Sure, you can run OSPF over tunnels, however XORP has no specific 
support for tunnel interfaces. If your host operating system has tunnel 
driver support, you need to configure XORP to use the tunnel driver. It 
sounds like you've already done this.

XORP does require that you assign addresses to the tunnel interface -- 
unnumbered interfaces are not supported.

At least FreeBSD and Linux will set the MULTICAST flag on gre 
interfaces. You may wish to verify that the IGMP messages are going out 
on startup using a packet sniffer.

thanks
BMS