The computer I am using right now has had some difficulty connecting to my wireless internet of late. I have to disconnect and reconnect it to the system to get it to work. Today, for the first time, I received an message frome the computer “Warning–system error. IP address conflict with an other device on the network.” The funny thing is that I am on the internet while I read the error message. What does this error message mean? How do I resolve the conflict, or does it not need to be resolved at all?
All machines need to be set up to use DHCP, or set up with manual IP addresses that are unique. Sounds like one or more of your machines have manual addresses.
There are five possibilities:
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You’re using static addresses (what some systems and beowulff call “manual”), and you assigned the same address to two machines. Exceedingly unlikely this could happen without you knowing about it.
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You’re using a combination of DHCP and static addresses, and the DHCP range overlaps the static addresses in use – you got unlucky, and were given a duplicate address by DHCP. You can fix this in your router by limiting the DHCP addresses, or just ignore it if it doesn’t happen often. More likely than the first case, but still not something that happens if you don’t know about it – it takes several steps to set up a static address, you’d probably know if you did it (unless someone else set up your network).
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Your router is slow to notice the disconnect of DHCP addresses, and it happened to give you the same one twice in a row (not uncommon), then complained when you tried to connect to it, because it happened to think an old connection was still active. This would be a router bug, technically, but it’s not going to be a big deal, and shouldn’t require any action on your part if it doesn’t keep happening.
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You’re using Windows Vista, which gives me these messages spuriously from time to time. I ignore them; as you note, it doesn’t actually affect access at all.
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You have more than one network connection in your system, both set to the same address, and both turned on and connected (wireless and wired at the same time, or Wi-Fi and Bluetooth, if your system can do that). I don’t think this can normally happen with DHCP, but there might be a case I’m not thinking of. I’ve done this to myself once or twice when testing network connections, but again it’s in the “it wouldn’t start happening by itself” category.
A neighbor might be accessing your wireless connection, and that person is using the same local IP address you are using. Do you have security activated on the wireless?
How many people are using the wireless router? Is it your router or are you piggy-backing on a roommate’s? Do you know how to access the router to see what IP addresses it has assigned by DHCP? Which brand router is it? And are there any bells-and-whistles in the network, like a range expander?
Meanwhile, you can check to make sure you aren’t the problem by going to Network Connections (from Control Panel or by right-clicking the icon on the lower-right of the screen). Right-click the wireless connection, click Status and then the Support tab. It should say “Address Type: Assigned by DHCP.” If not, with most routers, you’re probably the problem. To fix, go back to Network Connections, right-click Properties, scroll down to Internet Protocol (TCP/IP) and click Properties. Make sure “Obtain IP address automatically” and “Obtain DNS server address automatically” are checked.
BTW, IANAComputerGeek. Just a plugger who’s been stuck with trouble-shooting the house router. So, anyone should feel free to point out any errors or omissions in the above.