tunnel IP address

[Gregoux]

when do you need to affect an ip address to the a tunnel interface?

[kprakash · Accepted solution]

Hi Greg,

Are you talking about when do we configure IP address on a tunnel interface?

We use an IP address on a tunnel interface when:

a) Using VPN tunnel monitoring, ie pinging from the tunnel interface to a destination behind the remote peer

b) Using dynamic routing protocols to learn routes via the tunnel interface. We cannot have an unnumbered tunnel interface to participate in dynamic routing.

Hope that helps!

BR,

Karthik

[goku123]

Two most common uses would be:

1. Tunnel monitoring: so that the firewall can send pings sourced from tunnel interface to a remote endpoint to verify phase 2 reachability.

2. Dynamic routing over VPN: If you would like the firewall to learn remote network routes using a dynamic routing protocol such as OSPF, you would have to assign an IP to the tunnel interface so that the firewall can use the tunnel IP to neighbor with a remote router over the VPN.

[Gregoux]

another way that i found

is when you need to implement PBF to route to the tunnel interface

you need to implement an IP address on tunnel interface

and the next hop in the PBF rule need to be define with tunnel ip address.

[Vdionisio]

You can also define No IP Address on the Next Hop for Policy Based Routing though?