A company has implemented PPTP as a VPN solution. Which of the following ports would need to
be opened on the firewall in order for this VPN to function properly? (Select TWO).
A.
UDP 1723
B.
TCP 500
C.
TCP 1723
D.
UDP 47
E.
TCP 47
Explanation:
Which of the following ports would need to be opened on the firewall in order for this VPN to function properly?
A company has implemented PPTP as a VPN solution. Which of the following ports would need to
be opened on the firewall in order for this VPN to function properly? (Select TWO).
GRE packets use IP Protocol number 47, not either TCP 47 or UDP 47
Too complicated for a security+ exam.
The answer is A & C. Ports 1723 is for PP2P protocol in both TCP and UDP. http://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers
I agree with Mike.
A PPTP tunnel is instantiated by communication to the peer on TCP port 1723. This TCP connection is then used to initiate and manage a second GRE tunnel to the same peer. The PPTP GRE packet format is non-standard, including an additional acknowledgement field replacing the typical routing field in the GRE header. However, as in a normal GRE connection, those modified GRE packets are directly encapsulated into IP packets, and seen as IP protocol number 47.