Interlink between the two backbone switchs

[gkadudfo1]

Hi guys,

We are operating the two backbone switchs for redundancy with hsrp and eigrp.

I am wondering if I connect the two links (trunk and L3) or just one port (trunk or L3) between the backnone switch.

I attached the diagram that simply indicates the my concers.

In this case, what would be the best option ?

Please give me a recommendation.

Thanks,

[Giuseppe Larosa · Accepted solution]

Hello Younr-rae,

both HSRP and EIGRP requires L2 adjacencies so you need a L2 trunk on all the involved Vlans between the two switches.

If you like you can add a separate L3 link between the two as an added protection.

The minimum is a L2 trunk, you should consider the use of an etherchannel bundle with two member links configured as 802.1Q L2 trunk. In this case I recommend the use of LACP ( mode active) for better resiliency ( bundle only if LACP messages are exchanged on each member link)

Hope to help

Giuseppe

[gkadudfo1]

Thank you for your answer.

I think L2 adjacencies required for both HSRP and EIGRP might be avalable through the below  main switch.

Using the L2 trunk ports between the two switches migh form the loop architecture and it cause the

conversence times about 30sec when BB#1 down.

So, how about using the only L3 ports between the switches ?

Thanks,