VRRP - Virtual IP doesn't respond to pings
When implementing Virtual Router Redundancy Protocol (VRRP) as an FHRP, if the virtual IP is not owned by a physical device, it will not respond to ICMP echo requests (pings).
Other FHRPs such as HSRP and GLBP will have their virtual IPs respond to pings normally. However, VRRP does not, and this is part of its design.
VRRP can use either a non-assigned IP address as the virtual IP or it can use an IP address that is owned by one of the redundant routers as the virtual IP. In this case, the “IP Address Owner” is defined as the router that has been assigned the same address that is used as the virtual address. In such a case, the IP address owner also becomes the master device.
Now the RFC states the following:
The Master:
MUST NOT accept packets addressed to the IP address(es) associated with the virtual router if it is not the IP address owner.
MUST accept packets addressed to the IP address(es) associated with the virtual router if it is the IP address owner.
So in a scenario where the virtual IP is not owned by any device, if you ping the virtual IP address, then the router MUST NOT accept packets addressed to the virtual IP addresses. So pings will be ignored. However, if you configured the virtual IP address as one of the real assigned addresses on one of the routers, then those packets will be accepted and the pings will be responded to.
So to summarize, if the destination IP is that of the IP Address Owner, the ping will be responded to. If the virtual address does not belong to one of the routers, then it will not respond to pings.
Why is this? Well, the RFC gives the following reason:
Potential Forwarding Loop
A VRRP router SHOULD not forward packets addressed to the IP Address(es) it becomes Master for if it is not the owner. Forwarding these packets would result in unnecessary traffic. Also in the case
of LANs that receive packets they transmit (e.g., token ring) this can result in a forwarding loop that is only terminated when the IP TTL expires.
Links:
https://forum.networklessons.com/t/vrrp-virtual-router-redundancy-protocol/1151/82?u=lagapidis