You have recently deployed DMVPN Phase 3 for your WAN. Each of the spokes has a static IP assigned to it by the ISP, except one, which gets a dynamic IP. After a recent power loss during the day, the router rebooted, but was unable to bring the tunnel up to the hub immediately. The log on the spoke shows an NHRP registration reply from the hub indication an error.
%NHRP-3-PAKREPLY: Receive Registration Reply packet with error unique address registered already (14)
interface Tunnel0
ip address 17216.1.1.255.255.255.255.0
no ip redirects
ip nhrp authentication cisco
ip nhrp map multicast dynamic
ip nhrp network-id 10
ip nhrp holdtime 3600
ip nhrp redirect
tunnel source FastEthermet0/0
tunnel mode gre multipoint
Below is the configuration of the tunnel interface of Spoke 1
Interface Tunnel 0
ip address 17216.1.2.255.255.255.255.0
no ip redirects
ip nhrp authentication cisco
ip nhrp map multicast 1.1.1.2
ip nhrp map 172.16.1.1 1.1.1.2
ip nhrp network-id 20
ip nhrp holdtime 3600
ip nhrp nhs 172.16.1.1
ip nhrp shortcut
tunnel source FastEthermet0/0
tunnel mode gre multipoint
Which of these actions could solve this problem?
A.
Configure tunnel protection, with the appropriate cryptographic configuration on the hub and spokes
B.
Configure the no ip nhrp registration unique command on the hub, Hub 1
C.
Configure the ip nhrp registration no-unique command on the spoke, Spoke 1
D.
Remove the ip nhrp shortcut command from the spoke, Spoke 1