Conflicting IP Addresses? - Tilted Forum Project Discussion Community

MahlerIsGod · 11-14-2005, 02:43 PM

Greetings All,
All of a sudden I am getting a little popup from my status bar saying there is a "Conflicting IP addresses within my network." Nothing has changed within the network (that I know of) for months, so why now? When it occurs my connection dries up to almost nothing so I would like to fix this, if possible. We use the modem Comcast gave us and a Linksys WRT54G router. I dont know if that helps but i thought I should include it. Does anyone know anything about this? Thanks

PS Of the three connections, I am the only hardwired. The other two are wireless.

Cynthetiq · 11-14-2005, 06:53 PM

is everyone DHCP or static? maybe someone has wandered onto your wifi network and is using one of your same IP addresses...

since it's your machine you should ping your duplicate IP address and check out the MAC address, if they are different from your NIC/PC then someone is hanging out on your wifi network....

change the subnet octet of your DHCP server and let everyone get new addys and everything should be fine and that person won't be leeching from you.

phukraut · 11-14-2005, 08:06 PM

Alternatively you can just set the router so that only a certain number of IPs can be given out, just enough for all your boxes. Or you can set it so only boxes with certain MACs can connect.

samspade123 · 11-15-2005, 10:11 AM

Somewhere you have two machines using the same address. If you are using static on some machines and dynamic on others make sure that the static range is in the exclude list for the dynamic pool. Also, I would agree with phukraut - you should be using MAC address filtering (while not fool proof it will keep the random wifi users out).

Pragma · 11-15-2005, 02:30 PM

Telling the router to only give out a certain number of IP addresses shouldn't make a difference, as the router won't hand out conflicing IP addresses. The problem is that somewhere, someone has set up a computer with a static IP address - and that the DHCP server is trying to hand out a lease for that address and doesn't realize it's taken.

Check all of your computers to make sure that they're set to DHCP - and check and make sure nobody else is using the wireless part of your network.

cyrnel · 11-15-2005, 02:49 PM

Certainly, check the wired boxes for dupes, but an intermittent problem screams "wireless". I'd start by setting up WPA authentication/encryption for your wireless LAN. Intrusions aren't always intentional. People often connect to the wrong access point accidentally just by nature of proximity to their AP vs. your AP. If they're using static addresses in your DHCP range you end up with dupes. WPA prevents their access to your access point so negates the problem, as well as securing your WLAN against intentional attacks. WEP would also help, but it's very weak in comparison. MAC filters help but it only keeps very honest people honest.

11-14-2005, 02:43 PM	#1 (permalink)
MahlerIsGod At The Globe Showing Will How Its Done Location: London/Elysium	Conflicting IP Addresses? Greetings All, All of a sudden I am getting a little popup from my status bar saying there is a "Conflicting IP addresses within my network." Nothing has changed within the network (that I know of) for months, so why now? When it occurs my connection dries up to almost nothing so I would like to fix this, if possible. We use the modem Comcast gave us and a Linksys WRT54G router. I dont know if that helps but i thought I should include it. Does anyone know anything about this? Thanks PS Of the three connections, I am the only hardwired. The other two are wireless. __________________ "But a work of art is a conscious human effort that has to do with communication. It is that or its nothing. When an accident is applauded as a work of art, when a cult grows up around the deliciousness of inadvertent beauty, we are in the presence of the greatest decadence the West has known in its history."

11-14-2005, 06:53 PM	#2 (permalink)
Cynthetiq Tilted Cat Head Administrator Location: Manhattan, NY	is everyone DHCP or static? maybe someone has wandered onto your wifi network and is using one of your same IP addresses... since it's your machine you should ping your duplicate IP address and check out the MAC address, if they are different from your NIC/PC then someone is hanging out on your wifi network.... change the subnet octet of your DHCP server and let everyone get new addys and everything should be fine and that person won't be leeching from you. __________________ I don't care if you are black, white, purple, green, Chinese, Japanese, Korean, hippie, cop, bum, admin, user, English, Irish, French, Catholic, Protestant, Jewish, Buddhist, Muslim, indian, cowboy, tall, short, fat, skinny, emo, punk, mod, rocker, straight, gay, lesbian, jock, nerd, geek, Democrat, Republican, Libertarian, Independent, driver, pedestrian, or bicyclist, either you're an asshole or you're not. What's the best nation in the world? DO-NATION!

11-15-2005, 10:11 AM	#4 (permalink)
samspade123 Insane	Somewhere you have two machines using the same address. If you are using static on some machines and dynamic on others make sure that the static range is in the exclude list for the dynamic pool. Also, I would agree with phukraut - you should be using MAC address filtering (while not fool proof it will keep the random wifi users out). __________________ People in cars cause accidents, Accidents in cars cause people.

11-15-2005, 02:30 PM	#5 (permalink)
Pragma I am Winter Born Location: Alexandria, VA	Telling the router to only give out a certain number of IP addresses shouldn't make a difference, as the router won't hand out conflicing IP addresses. The problem is that somewhere, someone has set up a computer with a static IP address - and that the DHCP server is trying to hand out a lease for that address and doesn't realize it's taken. Check all of your computers to make sure that they're set to DHCP - and check and make sure nobody else is using the wireless part of your network. __________________ Eat antimatter, Posleen-boy!

11-15-2005, 02:49 PM	#6 (permalink)
cyrnel Adequate Location: In my angry-dome.	Certainly, check the wired boxes for dupes, but an intermittent problem screams "wireless". I'd start by setting up WPA authentication/encryption for your wireless LAN. Intrusions aren't always intentional. People often connect to the wrong access point accidentally just by nature of proximity to their AP vs. your AP. If they're using static addresses in your DHCP range you end up with dupes. WPA prevents their access to your access point so negates the problem, as well as securing your WLAN against intentional attacks. WEP would also help, but it's very weak in comparison. MAC filters help but it only keeps very honest people honest. __________________ There are a vast number of people who are uninformed and heavily propagandized, but fundamentally decent. The propaganda that inundates them is effective when unchallenged, but much of it goes only skin deep. If they can be brought to raise questions and apply their decent instincts and basic intelligence, many people quickly escape the confines of the doctrinal system and are willing to do something to help others who are really suffering and oppressed." -Manufacturing Consent: Noam Chomsky and the Media, p. 195

11-14-2005, 08:06 PM	#3 (permalink)
phukraut Addict	Alternatively you can just set the router so that only a certain number of IPs can be given out, just enough for all your boxes. Or you can set it so only boxes with certain MACs can connect.