Hi Jeff, Like you need any more advice at this point, but...
If you do decide to expand your subnet by changing the mask, you can obviate the need to reboot all of your DHCP clients if you've got enough lead time. Change the lease time of your current scope well in advance of the migration to something shorter than the current value but long enough to prevent a whole lot of extra chatter. Maybe down to 8 hours or something. Before you go home on the day before the big switch, change it once again to something obscenely short, like 5, 10, or 15 minutes. When you get there the next day activate the new scope and all your clients will be good to go within 15 minutes without restarting. Obviously there are lots of environment-specific considerations, but I had to go through something very similar recently and this is how I approached it and had no trouble at all. (Our environment is very similar in size and structure to what you described. I might find another way to approach this in a bigger shop.) Also, If you opt for changing the mask, you should be able to update the mask on all your static nodes in your spare time leading up to the day when you activate the new DHCP scope. From looking at the rest of the thread it shouldn't hurt anything to pre-configure the static IPs to /23 or whatever you choose. They'll also be ready to handle any traffic from the DHCP clients if you put the new scope's address range on the newly added part of the subnet. Just keep an extremely detailed document of your current configuration and modify it node by node as you make the changes. Planning, testing and record keeping are the keys to a glitch-free deployment. Lastly, if you do move to a /23, remember that your new addresses will be 192.168.0.X, not 192.168.2.X. Good luck, RS PS Don't forget to accommodate your reverse lookup needs - perhaps by pre-configuring a new reverse zone on your DNS servers. On Thu, Dec 17, 2009 at 3:59 PM, Glen Johnson <[email protected]> wrote: > Either way will work. Changing the subnet would be the less expensive > route except for your time. Do you currently use DHCP for all the IP. If > so, then that would be a quick solution. > > Change the DHCP lease to 1 day. Shut down everything except the DHCP > server, change the subnet mask and then bring everything back up, it should > get new subnet mask. > > If you have devices with manually configured IP addresses, then they would > obviously have to be changed. > > OTOH. If you have a switch with a built in router or a router with an > unused interface or a router and switches that support VLANS, then you could > go that route. > > This would not require shutting down everything and you could even do it > during normal work hours if you are careful. > > > > *From:* Jeff Johnson [mailto:[email protected]] > *Sent:* Thursday, December 17, 2009 3:49 PM > > *To:* NT System Admin Issues > *Subject:* Need more IP addresses > > > > I am in need of more IP addresses on my network. > > > > My current network looks like this: > > 192.168.1.x > > 255.255.255.0 > > > > I am using 248 IP’s currently, so I have very little expansion available. > I do see the potential to increase in the following year, so I had better > get my butt thinking about this soon. Plus I have Christmas and New Year’s > holidays that I could work with no one on our network for 3 full days. > > > > I am thinking about changing my subnet to something like 255.255.254.0 or > 255.255.252.0. Would this be a good way, or would I be better adding an > additional router and just creating a new 255.255.255.0 network on > 192.168.2.x? > > > > I guess my question is which is the “correct” way? > > > > *Jeff Johnson* > > *Systems Administrator* > > 714-773-2600 Office > > 714-773-6351 Fax > > [image: hydraflow] > > > > > > > > > > > > ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~
<<image001.jpg>>
