Which parameter must match on all routers in a DMVPN Phase 3 cloud?

Which parameter must match on all routers in a DMVPN Phase 3 cloud?
A . GRE tunnel key
B . NHRP network ID
C . tunnel VRF
D . EIGRP split-horizon setting

View Answer

Answer: A

Explanation:

NHRP network IDs are locally significant and can be different. It makes sense from a deployment and maintenance perspective to use unique network ID numbers (using the ip nhrp network-id command) across all routers in a DMVPN network, but it is not necessary that they be the same. https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/sec_conn_dmvpn/configuration/15-mt/sec-conn-dmvpn-15-mt-book/sec-conn-dmvpn-dmvpn.html