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Stuncle Eve · Aug 8, 2006, 08:07 PM

I just had a little window pop up that said:

IP Configuration (big red stop sign with ! in the middle)

xxx.xxx.x.xxx (my IP, according to System Prefs) in use by yy:yy:yy:yy:yy:yy. (Not my base station ID)
DHCP Server xxx.xxx.x.x (my router, also according to System Prefs).

Any idea what this means? Has someone hopped on my network (such as it is)? Any way to find out?

G4 iBook, Airport Extreme base station, Linksys router, WPA Personal security enabled.

ghporter · Aug 9, 2006, 10:15 AM

That's called an IP conflict-it means that your machine's IP is also in use by another machine, whose MAC address is the YY:YY:YY:YY:YY:YY data. It wouldn't be your base station, but rather another computer.

I have a lot of questions about your setup, starting with which device (AEBS or Linksys) is providing DHCP addresses, and including which Linksys router you have. It's quite possible you have been hopped onto by someone else, and there are ways to stop it and prevent it in the future, but I need to know how everything is set up before I start giving advice.

Stuncle Eve · Aug 9, 2006, 12:05 PM

Glenn - thanks for your reply. I'm at work now, but when I get back home I'll get that info for you.

SE

Stuncle Eve · Aug 9, 2006, 11:30 PM

Originally Posted by ghporter

That's called an IP conflict-it means that your machine's IP is also in use by another machine, whose MAC address is the YY:YY:YY:YY:YY:YY data. It wouldn't be your base station, but rather another computer.

I have a lot of questions about your setup, starting with which device (AEBS or Linksys) is providing DHCP addresses, and including which Linksys router you have. It's quite possible you have been hopped onto by someone else, and there are ways to stop it and prevent it in the future, but I need to know how everything is set up before I start giving advice.

Here's the basic setup: DSL in to D-Link DSL 300G modem, to Linksys BEFSR41 v.3 Etherfast Cable/DSL router with 4 port switch. One port goes to G5 iMac, one goes to AEBS. I'm not sure how to tell which device provides DHCP addresses - where would I find that out?

New info - I just checked the MAC address of the iMac, & it matches the YY:YY:YY:YY:YY:YY data, so there's no serious security problem. What's puzzling is that we've had this setup for at least a year, & have never gotten this alert before.

Who knows?

ghporter · Aug 10, 2006, 07:17 AM

The alert was probably because of the order you turned on the computers and when their DHCP leases expired-a fluke, in other words.

You can tell which device is giving out IP addresses by looking at the addresses themselves. The Linksys router (I have the same model) will by default give out addresses in the 192.168.1.x range (typically from .100 to .199), while I think the AEBS uses 10.0.0.x (but definately not a 192... address). The reason you should still be interested in this is that if you have both devices giving out addresses, your wireless computers won't be able to connect with your wired ones, and vice versa. Having only one device with an active DHCP server (I suggest the router) makes things much smoother for file sharing.

You can turn off both DHCP and the AEBS's router functions (superfluous in your setup) through the Admin Utility.

Floyde · Sep 1, 2006, 07:56 AM

Ahaaa.. this seems to be the thing I had this morning. I have a Netgear router which has an Airport base station plugged into it. I'm using a powerbook with wireless card and xp pc with wireless card. I got a message this morning mentioning two local ip's and that the base station couldnt connect.. the xp laptop could still get teh net but the powerbook couldnt.
I restarted the powerbook and switched the netgear off and the base station said it had conencted again but still the powerbook can't surf the net. I guess I should power down the airport and try again?