Non Distrubtive Core Switch Repacement

[rsrikant]

I have a pair of L3 Core switches (Nexus 7K) where my server farm switches are connected (L2 Switches)

I want to replace  these L3 Core switches with new Nexus series.

L3 Core switches are defined for Routing (OSPF), HSRP, VPc. I have to do non distributive migration from the existing switches to the new switches.

I have attached diagram for your reference.

One of understanding is that, need to extend the existing VLAN from existing Core switch to the new Core switch & change HSRP & D.G

Is this correct. If so what are the step by step things which needs to be done. Also how about the cabling. What is the best approach for the cabling i need to do.

I would like to have detailed inputs which will help in non disruptive migration

[Philip D'Ath]

This is almost impossible to answer without knowing a lot more about the environment and the applications.

If you could tolerate short outages, say 180s, you would probably make life much easier for yourself.  You are going to have to be very careful about convergence times, such as for spanning tree, ospf and hsrp.  You will have to be careful about any IP addresses change MAC addresses and the impact on ARP caches on other devices that have already learnt the (IP,MAC) binding tuple.

[rsrikant]

Thanks

I understand your point.

But if you can let me know what is the standard and best practice which needs to be followed I will be useful for me. I understand that there will be impact. But would like to know which is the best method by which we can reduce the downtime & what are the steps.

If any specific details are required let me know i can provide.