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Right now, in my office, we have a Cradlepoint MBR1000 wireless router as our DHCP server. It's not as configurable as I'd like for it to be, and I need to set up a VPN, so I am considering replacing it with a dedicated box running Zeroshell.

I'm wondering this: If I set this system up and make it our DHCP server, will it re-assign all the IP addresses at random (or in an otherwise different fashion than they already are)? What determines what IP address a device gets from the DHCP server? I've got some scripts and crontabs set up that depend on things being exactly as they are, so I'm a little nervous about changing anything so substantial.

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up vote 1 down vote accepted

You'll have some weirdness until the PC's and devices get new IP's. It may get ironed out with a restart. Otherwise you might have to to go machines acting wonky and do a manual release and renew of the IP.

Many machines, especially Windows, will try to get their old IP back, and if they fail to get it are supposed to renew it.

You will want to make sure you don't have any devices that are statically configured with an IP and that your new DHCP server hands out addresses within your old server's range so you don't step on devices with static IP's.

If you have scripts that depend on IP's staying as they are, why are you handing them out with DHCP? The devices you need to keep static should be assigned statically; in a small network, I'd set up a block of IP's for the DHCP server and another block divided for particular devices like printers and servers and aren't in the DHCP server's range.

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Thanks, I figured that would happen. I'll have to investigate whole 'static IP' issue - I never thought of that. – kivetros Mar 29 '11 at 14:44

You should be able to 'hard code' DHCP entries into the lease table but, yes, if the clients and the Server are set to allocate IPs on the fly, you'll get random IPs.

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