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Community Member


I currently have the addressing scheme set

and I am running out of addresses so I am going to change to

only have 1 gateway

before I can get to every single machine to change them all some will be on one scheme and the rest on the other

my question is..can I setup the router to recognize both until all are on the same address scheme?

and afterwords will i need to change the router's mask?

VIP Purple

Re: supernet


the problem is that you have overlapping address spaces, so you cannot use both on the same router or use a secondary address. The only option is, as far as I can see, to put another router into your network temporarily during the migration.



Re: supernet

You can try playing tricks for a bit... Of course the easiest thing to do would be convert everything on your network to DHCP, lower the lease time down quite a bit, then change the netmask on the scope and hope everything continues working...

If you leave the default-gateway the same, all the devices >should< be able to continue getting "out" of the network, even if the routers netmask has changed. But, devices still using the "old" netmask won't be able to communicate properly with those that aren't in its original subnet.

If you change the default-gateway in either case, you will probably have problems with traffic leaving the LAN unless you get everything changed at once.


Re: supernet

yeah I have setup dhcp with the new netmask and if I can do it at night and get everyone done I might be ok...because I could like you said shorten lease times then shutdown the old dhcsp service...just worried about static machines and switching servers over to new netmask so they all communicate correctly

Community Member

Re: supernet

Here is something you can try. We are running it here. You can take a bit from the subnet mask to give you more host. Instead of using

You could use /23

The only thing is that you will need to make sure that you are not using because this will now be apart of the 192.168.100 subnet.

You will have 512 hosts from address range -

You will set your gateway to You will set all of your servers to point to this gateway. This will allow you to only change the subnet mask and keep all of the IPs already assigned. One change and you are done. Now if you need more than 512 hosts then we could do something different. Under the 512 then this would be my recomendation. HTH, Brandon

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