How to complete a network migration without service interruption?

[momotaro]

Hi,

Am trying to replace a hospital network with a new architecture without stopping it?

current network : hp and 3com swichs on bus topology
mine cisco 4500.

best regards.

[sicarie]

Good luck! my advice is plan and test, then plan and test again. Have well documented and communicated plans, as well as good "rollback" options.

Eventually you're going to have to physically unplug cables, so I would probably spend a bit of time planning that stage. If you are able to stage the gear right next to your current gear, then the amount of time plugging and unplugging will be minimal - especially if you've already moved through and documented/tagged the cables.