A network contains a remote tunnel interface and firewalls in the network path of each router. An attempt to ping the IP address of the remote tunnel interface fails. Which connections should be allowed through the firewalls? A. IP protocol 50 B. TCP port 1723 C. TCP port 47 D. IP protocol 47
It will be either IP protocol 50 (ESP) or IP protocol 47 (GRE). If this is a secure connection then the answer is A. The GRE tunnel would be encapsulated in the IPSec tunnel so not visible to the firewalls.
