L3 Core migration with Old core

[knaik99]

Customer wants to change old core (one pair) with new core (one pair) and customer can give only one hour downtime

so we decided to put Layer 2 LINK between new core and old core and we are going to put SVI on new core in shut down mode except management new VLAN so new core will behave like L2 access switch which just pass Vlan.

and in down time we will convert new core to L3 functioanlity and remove old core

1.will it work?

2.what precautions ,we should take at that time except above?

[Reza Sharifi]

Depending on the size of the network and how much preparation you do ahead of time, one hour may not be sufficient. 

Are you connecting the access switches to the new core during this one hour? How many access switches you have? How many vlan and SVI do you have? Are you planning to move the same SVIs with the same IPs to the new core?

HTH

[paul driver]

Hello

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@knaik99 wrote:

Customer wants to change old core (one pair) with new core (one pair) and customer can give only one hour downtime

so we decided to put Layer 2 LINK between new core and old core and we are going to put SVI on new core in shut down mode except management new VLAN so new core will behave like L2 access switch which just pass Vlan.

and in down time we will convert new core to L3 functioanlity and remove old core

1.will it work?

2.what precautions ,we should take at that time except above?

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It is defiantly possible has I have completed it on a few occasions , Though I would say you need a larger change windows than 60 mins just for contingency.
When you say old-new pair what do you mean-, can you elaborate on your topology

[balaji.bandi]

As Long as all the pre-requisite met, you can achieve this depends on number of the Links.

steps :

1. make sure you offload the config out of the boxes.

2. Load the config to new cisco Switch check all the configuration loaded with out any errrors.

3. make sure new switch has latest security patches applied code, like 5 Star rated.

4. do some hardware sat tests

5. Prepare for Patching information and validated

6. Look for manpower who understand better on this environment. (in case any issue you can role back)

7. make sure users ready to test in the enivironment as you moving the Links from old to new.

Hope this steps help you. Done many -- prep work is the must. and act accoriding when any issue occurs.