HA: vCluster, VDOM and InterVdomLinks

[Yngve0]

I am trying to set up a HA-design with 2 vDoms. For load balancing reasons I want to locate the two vDom’s in different vCluster with separate active/ passive priority.

A problem occurs when the two vdom need to share some infrastructure and therefor inter-vDom-links are needed.   I know vdom-link across vcluster is not supported, and physical links should be used. This give another problem, since overlapping subnets is not allowed by default. I know this can be changed by a systemsetting, but is such design supported?

As far as I understand; physical inter-vDOM-links needs 2 software switches with two physical interfaces each on both HA-member; together 4 interface on each member:

SoftSwitch1@member1 <=> SoftSwitch2@member1

SoftSwitch1@member1 <=> SoftSwitch2@member2

SoftSwitch1@member2 <=> SoftSwitch2@member1

SoftSwitch1@member2 <=> SoftSwitch2@member2

Is this correct or am I complicating the design here and will this work?

[emnoc]

This came out way cheaper than a small ISR and you could use any opensource router ( bird, quagga/zebra,etc....) and add one hop ( vyatta )

It's probably better than crafting softswitch and wastes no additional ports. This setup works great in a stack env like cisco or juniper switches. If you had a L3 Switch, you could do the vlan 61/62 for example as a SVI  and if required in a vrf-lite if the situation warrants. BTW: I think the customer in this case did actually do that, I didn't follow up on what happen.

We later started plumbing dual 1gige ports to the virtual stack so we have pretty much 100% multi-path and the  vyatta instance was on a ESX server with HA for the vyatta instance.

Just food for thought.

[Yngve0]

emnoc wrote:

This came out way cheaper than a small ISR and you could use any opensource router ( bird, quagga/zebra,etc....) and add one hop ( vyatta )

Thanks, 

I consider 2 different designs; and in both scenarioes the WAN-access is shared. I feel that adding a third part router linke vyatta will make the design more complicated to debug and maintain.