What is the best way to swap routers in a commercial premise at the same time as upgrading the Subnet to allow for more IP Add

Jon2263

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Jun 7, 2014
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On Monday we are installing a new leased line router and moving away from our old DSL router.

At the moment we are operating using a 255.255.255.0 Subnet but want to move to a 253 subnet to increase the number of addresses available when we make the swap.

My concern is that we have alot of equipment such as IP Cameras with static IPS that I cannot get to in order to reset so all amendments have to be done through web interfaces.

Is it possible to have both routers on the network at the same time and one by one move items across to the new network?
 
Solution
To a point if you are very careful. The machines using the old subnet mask will not be able to talk to the machines using the new subnet mask. You would have to be very careful not to allow your dhcp server to give out any ip in the old block or you would get duplicates. You likely would have to assign the new router a IP that not the fairly standard lowest address since it would overlap your current one....it depends where you pick your /22 network to start.

There are lots of nasty tricks you can play with static ARP and such also but I would change the mask as quickly as possible. You can leave the IP the same as long as you ensure it won't duplicate.
To a point if you are very careful. The machines using the old subnet mask will not be able to talk to the machines using the new subnet mask. You would have to be very careful not to allow your dhcp server to give out any ip in the old block or you would get duplicates. You likely would have to assign the new router a IP that not the fairly standard lowest address since it would overlap your current one....it depends where you pick your /22 network to start.

There are lots of nasty tricks you can play with static ARP and such also but I would change the mask as quickly as possible. You can leave the IP the same as long as you ensure it won't duplicate.
 
Solution