You want to troubleshoot a GRE tunnel that is configured with an ACL. Which two tasks must you perform? (Choose two.)
A. Verify that the ACL permits TCP port 8080.
B. Verify that the ACL permits IP protocol 47.
C. Verify that the ACL permits TCP port 1723.
D. Verify that the remote device is reachable across the network.
E. Verify that the IP addresses of the physical interfaces are on the same subnet.
B D are correct. Think about it, “can be used in conjunction with “PPTP tunnel” which is obsolete method of implementing VPNs”, so pptp can or cannot be included in the setup, there is nothing in the question about that. But reacheability is a must int troubleshooting in every setup, the acl part is already taken care with B, but you cant assume reacheability with just BC. So, B D are correct
The question concerns ACL related diagnostics so I think BC is correct.
in the wide GRE diagnostics we need to check much more among others reachable destination network.
GRE is protocol 47 and it can be used in conjunction with “PPTP tunnel” which is obsolete method of implementing VPNs. PPTP is instantiated by communication to the peer on TCP port 1723
So since we are troubleshooting “GRE with ACL” not “reachability” better answer may be B,C. Correct me if iam wrong…