iMac causing network problems

[hubbyho]

Hi guys.
I will try to keep this as short as possible.
Girlfriend just got a new iMac all in one a week or so ago. We had no problem setting this up on the exsisiting network but a couple days ago we began having issues. The 3 PCs, 2 iPods and one network printer seem to connect fine until the iMac connects (or tries to). We've gotten IP confilct errors on various machines (assigning already assigned IP address). I cannot even connect to the router when the iMac causes this problem. Take the Mac off, everything runs fine. I am new to the Mac world so maybe I'm missing something.
Here's what my network consists of...
Scientific Atlantic DPC2203C cable modem (Optimum)
Netgear WGT624 v3 router
1 iMac all in one, 2 HP and one Gateway PC(all Vista), 2 iPod touch, 1 HP wireless printer all running DHCP and wireless.
Please help. THis is frustrating!!!!
Thanks
Don

 

[BlueRevolution]

Take a look under

 -> System Preferences -> Network -> AirPort

Verify that your settings look like the attached image. If so, you could also try renewing the DHCP lease.

You've probably already done all of this, but that's all that comes to mind.

 

[hubbyho]

thanks BlueRev. Those are the current settings and I have renewed the lease. Unfortunatly when I renew the lease it seems to allow a connection (on some machines including the iMac) for less than a minute. Then back to no connection on any machine.

 

[dr. shdw]

Set static IP address based on the MAC address on the router so that there aren't any conflicts.

 

[hubbyho]

Seems as though WEP encription is causing an issue. Deos this make sense to anyone???? I do not like using an unsecured network but everything seems fine with WEP turned off. For now anyway.

 

[dr. shdw]

Seems as though WEP encription is causing an issue. Deos this make sense to anyone???? I do not like using an unsecured network but everything seems fine with WEP turned off. For now anyway.

Some routers are picky. Is the iMac up to date?

 

[shawnathan]

Seems as though WEP encription is causing an issue. Deos this make sense to anyone???? I do not like using an unsecured network but everything seems fine with WEP turned off. For now anyway.

Yes, I believe WEP is the problem. My wife's parents had the same problem at their house. 2 PCs on the network and 1 Macbook Pro. I tried EVERYTHING to fix it, or so I thought. I switched the security on the router to WPA2 instead of WEP and now everything works great! Theirs is also a Netgear router, so perhaps it has something to do with Macs vs. Netgear. Hope this helps.