What is the purpose of the NHS command on the spoke nodes in the DMVPN topology?
SPOKE-02(config-if)#ip nhrp nhs ?
A.B.C.D Protocol IP address of NHS
cluster NHS Redundancy cluster configurations
dynamic NHS protocol address dynamically learnt
fallback NHS Redundancy Fallback time
What does each one do? Why do I see this command in most config examples defining the hub?