Which UDP port is associated with Teredo?

Which UDP port is associated with Teredo?

• A. 53
• B. 80
• C. 3544
• D. 123

Answer: (C)

Teredo is a IPv6 transition mechanism that tunnels IPv6 inside UDP to traverse NATs, so it relies on a dedicated UDP port for its tunnel traffic. The standard port used by Teredo is 3544, which is why this port is associated with Teredo. The other ports listed correspond to unrelated services—53 for DNS, 80 for HTTP, and 123 for NTP—so they aren’t tied to Teredo.

Teredo is a IPv6 transition mechanism that tunnels IPv6 inside UDP to traverse NATs, so it relies on a dedicated UDP port for its tunnel traffic. The standard port used by Teredo is 3544, which is why this port is associated with Teredo. The other ports listed correspond to unrelated services—53 for DNS, 80 for HTTP, and 123 for NTP—so they aren’t tied to Teredo.