GRE tunnel source multiple interfaces?

[hengsty]

Is it possible to assign a single GRE tunnel to two source interfaces?

The reason we would want to do this temporarily is to transition our DMVPN public addresses from one IP space to another.

[Philip D'Ath · Accepted solution]

No it is not.  However you can add an additional GRE interface using the new physical interface.  Be careful with your routing to send the right traffic out the right interface.

[hengsty]

Good point, thank you.