What multicast address does VRRP use for sending advertisements?

VRRP, which stands for Virtual Router Redundancy Protocol, uses the multicast address 224.0.0.18 for sending its advertisements. This specific address is designated for use by routing protocols and is within the reserved range for multicast addresses.

When a VRRP router (the master) sends out advertisements to inform other routers about its availability and the current virtual router's status, it uses this multicast address to ensure that only the relevant routers (those that are VRRP-enabled) receive the packets. This is efficient since it allows for the communication between multiple devices in the same network segment without flooding all devices with unnecessary traffic.

Utilizing the correct multicast address ensures proper function within a network environment, allowing for redundancy and failover capabilities, which are critical to network reliability.