A VIA client tries to initially connect to corporate office controller through an intermediate firewall. However, the VPN connection fails. The administrator examines the firewall rules and determines that rules for UDP 4500 and UDP 500 are configured.
Which additional protocol must be allowed in the firewall rules to resolve this connection failure?
To resolve the connection failure of a VIA client attempting to connect to the corporate office controller through an intermediate firewall, the firewall must allow the ESP protocol. ESP (Encapsulating Security Payload) is part of the IPsec suite, which provides confidentiality, data integrity, and authentication. Protocol ESP often requires allowance through firewalls to ensure that encrypted traffic can pass through, even when UDP 4500 and UDP 500 are already configured for IPsec key exchange and NAT traversal.
I think D. ESP, the question is PROTOCOL not a port. ESP is IPsec protocol number 50 that passes through UDP port 500
Wrong. As you mentioned, ESP passess through UDP port 500 is allowed on firewall policy. The answer should be B, TCP 443. It was not mentioned that this is allowed on the firewall. This is essential for the client to login and download VIA installer
B. TCP 443
B. TCP 443 should be the right answer