What transport protocol and port are used by GDOI for its IKE sessions that are established between the group members and the key server?
Click on the arrows to vote for the correct answerA. B. C. D. E.
The correct answer is E. UDP port 4500.
Group Domain of Interpretation (GDOI) is a protocol that is used to establish security associations between the group members and the key server. The security associations are used to encrypt and decrypt multicast traffic. GDOI uses Internet Key Exchange (IKE) protocol to establish and manage these security associations.
IKE protocol is used to authenticate and exchange encryption keys between two devices. IKE protocol is used for GDOI to establish an IKE session between the group members and the key server. The IKE protocol can use either UDP or TCP transport protocols. The default port used by IKE protocol is UDP port 500.
However, if the IKE session is established over a NAT device, then UDP port 500 may not work. To overcome this limitation, the IKE protocol can use NAT-T (Network Address Translation-Traversal) mechanism to encapsulate the IKE packets within UDP packets. The NAT-T mechanism uses UDP port 4500 to encapsulate the IKE packets.
Therefore, the correct answer is E. UDP port 4500 is used by GDOI for its IKE sessions that are established between the group members and the key server.