VRRP Design - Multiple VRRP Instances

[Hannibal]

Hi Cisco Community, The best Community of the Internet

Let me to open this link to know a bit more of the VRRP Designing topic.

I have to develop an interesting project that consists of joining three ERPS rings. Each of these three ERPS rings must have a connection to each of the other two ERPS rings.

For example:

1. There are 3 ring networks: ERPS 1, ERPS 2 and ERPS 3
2. SW1 and SW2 belong to the ERPS 1 ring
3. At the same time, SW1 of ERPS ring 1 also belongs to ERPS ring 2
4. And, at the same time, SW2 of the ERPS 1 ring also belongs to the ERPS 3 ring
5. And, there is also a SW3 that belongs to the ERPS 3 ring and to the ERPS 2 ring

According to what I have read, I want to do the following:

• Create a VRRP instance 1 between SW1 and SW2 for Ring ERPS1
• Create a VRRP 2 instance between SW1 and SW3 for Ring ERPS2
• Create a VRRP instance 1 between SW2 and SW3 for Ring ERPS3

Is this possible ??

How many VRRP instances I could to create

I attach the design file that I want to consult with this great community of Cisco Guru

[Flavio Miranda · Accepted solution]

Hi

 According to cisco docs, routers support up to 100 VRRP instances.

But, looking your diagram, I am not sure VRRF is the right thing here unless I am missing something. 

Usually I see VRRP used to allow failover between two routers. On the Lan side I can point to a VIP ip address as my gatreway and I dont care which router is the active cause if one drops, the traffic is forwarded through the other.

 But I do need a switch netween then to allow VRRP messagens to be exchanged.  

Are we on the same page here?

[David Ruess · Accepted solution]

Hello,

A few questions.

-Are these switches (L2 or L3) or are they routers. I only ask because you have them labeled as switches but have the picture of what's mostly used as a router.

-Are all 3 rings separate networks? As in do they have different subnets, or are they all interconnected with specific configuration connecting the rings?

Its definitely an odd design, but I think I understand what you're trying to do.

This goes for all 3 VRRP instances you want to create but is this correct:

ERPS ring 1 uses SW1 and S2 as the VRRP default gateways? Same goes for each ring with respective connected switches?

If that's correct then I would consider where the traffic goes. If it uses SW1 as the GW then it will empty into Ring 3, if it uses SW1 as the default gateway traffic will empty into Ring 2. Most First Hop Redundancy Protocols send traffic to the same if not similar destinations. YOU would then need to make sure each Ring knew how to forward/route traffic for the other rings in the topology.

-David

[Georg Pauwen · Accepted solution]

Hello,

I agree with @Flavio Miranda, it is not really clear looking at the design what the function of the switches is. Are these layer 3 switches (I assume they are because otherwise VRRP would not be an option anyway) ? How are they connected to each other ? Can you post the configs of the switches (and put a description on the interfaces connecting the switches) ?