Number of vlans per VRID Instance (vrrp)

[alexreload2000]

Hello
Dear, I have the following question

HOW MANY VLANS ARE SUPPORTED BY EVERY INSTANCE VRID IN PROTOCOL VRRP ????

I have 2 Blackdiamond 8810 with EXOS 15.1.1.6

[Tomasz · Accepted solution]

Hi Alex,

If I remember correctly, when you specify a VRRP instance, you put commands with pairs of VLAN + VRID. IMO having something like vlan1+vrid1, vlan2+vrid1, ..., vlan3+vrid1 doesn't mean that you have one instance of VRRP, but effectively yes, your switch participates as VRRP member for 10 VLANs with the same ID.
For every VLAN (network segment) a VRRP router advertises (broadcasts - VLAN is the boundary) its VRID configured for that VLAN (so in a single network segment there can be many redundant gateways to different networks behind).

1. If you had two different VRRP clusters in exactly the same VLAN, with the same VRID, you would have one big cluster of 4 VRRP members - that's not what we want.
2. If you had different VRIDs for each VRRP cluster in the same VLAN, it's OK, clusters are independent.
3. If you had same VRIDs for different VRRP clusters (or even the same pair of switches) for many VLANs, it's OK, there should be no interference between advertisements as they are contained in different VLANs and from my understanding there is VRRP process running for each VLAN independently (that's why you have just 7 VRIDs available per switch but 256 VRRP instances total).

Hope that helps,
Tomasz

[alexreload2000]

@Tomasz

Thanks for the response, sorry for my English that is not very good but I hope you understand.

Currently in the Blackdiamond 8810 that I have with EXOS version 15.1.16. It is required to pass vlans (L3) that currently have an ESRP protocol to VRRP protocol. The number of vlans I have in this condition in my team are 28 vlans that I must pass to VRRP.

I will have some problem as an example of having 10 vlans configured VRRP protocol with VRID 1 is secure, will the protocol work well ?????? or is there a limit number of vlans per instance ???

I need that confirmation since currently the ESRP protocol configured with host mode is giving me problems and it is more transparent and clean that VRRP has been configured in the BLACKDIAMOND 8810.

[Tomasz]

Hi Alex,

It's late here but I hope I get the question well.  And I think it should be spoken different way. VRRP is about L3 gateway redundancy for LAN segment (VLAN). Thus, it's about IP addressing. Your VLANs can only have unique IP addressing compared to other VLANs present on the switch, thus single VRIP will be accessible just per single subnet, so the answer is: one. One VLAN can be served by one VRRP instance, but you can have many VRRP instances in one VLAN.

And VRID itself can be re-used, according to 15.1.1 release notes you can have up to 256 VRRP instances per BD 8K, 7 unique VRIDs available per switch and per VLAN.

Hope that helps,
Tomasz