An engineer must configure a GRE tunnel interface in the default mode. The engineer has assigned an IPv4 address on the tunnel and sourced the tunnel from an Ethemet interface.
Which additional configuration must be made on the tunnel interface?
A . (config-if)# ip mtu <value>
B . (config-if)# tunnel destination <ip address>
C . (config-if)# keepalive <seconds retries>
D . (config-if)# ip tcp adjust-mss <value>
Answer: