VRRP uses which UDP port?

VRRP uses which UDP port?

• A. 112
• B. 69
• C. 1521
• D. 1900

Answer: (A)

VRRP is an IP-layer protocol, not something that rides on top of UDP. In IPv4, the Protocol field in the IP header tells you what kind of payload is carried next. VRRP uses the Protocol value 112, so its messages are encapsulated directly in IP datagrams without a UDP header. Because of this, there isn’t a UDP port associated with VRRP. The other numbers point to different services that do use UDP ports, not VRRP. For example, 69 is used by TFTP, 1521 by Oracle Net, and 1900 by SSDP. They’re unrelated to how VRRP identifies its messages. So the correct concept is that VRRP is identified by the IP protocol number 112, not by a UDP port.

VRRP is an IP-layer protocol, not something that rides on top of UDP. In IPv4, the Protocol field in the IP header tells you what kind of payload is carried next. VRRP uses the Protocol value 112, so its messages are encapsulated directly in IP datagrams without a UDP header. Because of this, there isn’t a UDP port associated with VRRP.

The other numbers point to different services that do use UDP ports, not VRRP. For example, 69 is used by TFTP, 1521 by Oracle Net, and 1900 by SSDP. They’re unrelated to how VRRP identifies its messages.

So the correct concept is that VRRP is identified by the IP protocol number 112, not by a UDP port.