Forcing a New IP Address

Two easy ways: a) change the client's MAC b) assign the IP to another device.

Most routers have some sort of "static dynamic IP" page where you can force the router to always assign the same IP to a specific client. Use this to assign the IP you don't want to a dummy host.

The question is, why do you want to do this? The most obvious reason I can think of is that there's some sort of IP-based filtering or restriction on your LAN?

the router to always assign the sameIPto a specific client. Use

This is a simple home network (two laptops). I run into some kind of problem (probably interference of some kind) where I can connect to the router, but cannot connect to the internet. When you go through the "Network and Sharing" path to "Diagnose" the solution is typically to acquire a new IP address. This happens often enough to be irritating, but not consistently enough to track it down.

What I am really hoping for is a simple way to force this that my non- networking wife can do when she can't get an internet connection and I am not around. The 'Diagnose' path is a tad cumbersome to get to and doesn't necessarily generate a "get a new IP address" option, even when that will fix it.

dave

Sounds to me like you have reached the wrong diagnosis. If you can connect to the router then your local addressing is OK. Sounds like the router has a problem or more likely the DSL connection. You could look ato see if the router is "connected".

If you post the exact model, sub-version, and software version of the router someone here may well be able to suggest a software upgrade. Otherwise upgrade to the most recent.

Have you tried rebooting the router when the problem occurs? This may be inconvenient but is easy for non-experts to implement?

Rebooting the router works fine in these cases.

But when you go through the "Diagnose" path, "get new IP addresses" is virtually always the solution. I was just looking for a way to force it. Is that what "ipconfig /renew" does? If so I guess I could build a short script that would do it.

Thanks.

dave

Try changing channels, and try a scan of your local area with netstumbler to see what channels your neighbours are using. Also watch our for cordless phones, microwave ovens, video senders etc that share the same frequency as WiFi. Perhaps you're just out of range? Ignore the nonsense from manufactureres about 300ft range, if you have walls with the wrong material in, its more like 300 inches...

This is purely because windows is boll*cks at sorting network problems.

When it loses network connectivity due to interference, out of range or whatever, windows generally drops its dynamic IP address (really it shouldn't do this - it should retain it till the lease expires).

When the interference clears up Windows tries to "repair" the connection which means asking your router for an address again. Your router however shouldn't be handing out a new one each time - each PC should pretty much invariably get back the same one it had last time.

Either way, getting a new IP isn't solving your problem - its a coincidence. Its like your car keeps breaking down on your drive to work. Each time you get a lift from a different passer-by, but thats just happenstance - you could equally have got a lift from the same guy each day. And the cure isn't to pick a random passer-by to hitch with each day, the cure is to fix your car so it doesn't break down.

Your best bet is to solve the interference / connectivity problem so that your laptops don't lose connectivity in the first place. I know these can be barstewards to fix, but otherwise you're just putting sticky tape on the leak.

Re: Very helpful stuff attached

Thanks for the details, Mark.

This isn't an out of range condition as it will happen sometimes from 6' (same room as the router).

But it almost always happens when the laptop is coming out of hibernation mode. All of my drivers are current (Intel PROSet card) and I've done everything that I can think of with power management without success. The only thing that has helped is changing the channel.

But maybe this is an issue with my wireless card and coming out of hibernation, although that seems inconsistent with a channel change being helpful.

Thanks again for your comments.

dave

Dont know what there are.

ipconfig /release ipconfig /renew

does a DHCP release then renew:)

You may want to look at the netsh commands. You can get the wireless status from there.

Got it - thanks.

dave

Aha, that snippet was missing first time! I think this is virtually a FAQ. Lots of wireless cards driver software is poor at handling wakeup from hibernation.

Personally I find hibernation more trouble than its worth and just restart the laptop each time (it costs a few seconds but is less painful than mollocking around getting ancillary stuff working properly again).

My suggestion? Tell your missus to shut the laptop down rather than hibernate....

If changing channel helps, then you have an interference issue as well, I'm afraid.