I cannot get access to the router as this is a university network,
You should really talk to the University network people...
but since other computers work fine it isn't a router issue.
Not true. I would hazard that it is most likely a router issue since
it is the router that is handing out IP addresses and for some reason
doesn't like one of your machines.
You say the machine "recently lost the ability..."
How long ago?
Was anything done just before it stopped working? Upgrade? Installation?
You also say that both can connect via wireless. Is this at the uni or
some other location?
I'll check with the uni IT folk, but they are notoriously slow to respond.
As for how recent it lost the ability, well we bought the laptop 3 months ago and I set it up for my wife back then and it definitely could connect back then. Since then she mainly uses it on the wireless network (yes its the uni network, with the same DNS servers).
In the meantime she hasn't installed any software than I know off, and she hadn't even installed any updates, which I did while troubleshooting to no effect.
I was hoping the very specific nature of the problem would help in that
It cannot obtain an IP via DHCP
It CAN use another IP via DHCP with Manual Address
That alone should rule out the normal glut of networking issues, no?
I have met similar problems before. And I tried to enlarge My DHCP Address Range, Like before it was 10.1.0.1-10.1.0.100, try to enlarge this to a bigger range, 10.1.0.1-10.1.0.200.
My Understanding was when the DHCP ip pool was all assigned out to clients and not up to the least time. The DHCP Server can not assign ip address to client any more.
Hope this helps.
I have the same issue, although mine is on a mac mini. It's very hard to search for this problem on the internet because it is so specific. To restate the problem:
The wireless ethernet connects to the same router and acquires it's IP address, DNS, and router information through DHCP without a problem.
The wired ethernet connection is unable to communicate with the DHCP server. The router detects it, and sees it as having it's self-assigned ip address (169.254.74.247). The subnet mask is wrong (255.255.0.0 vs. 255.255.255.0) as well. Both are greyed out. I've tried all of the obvious steps (restarting networking, rebooting everything, disabling airport, etc.) to get it to work and like the guy above, I can get it to connect with a manually assigned IP.
I have had this issue with multiple routers. Currently I'm using a gigabit-e router - netgear WNDR3700. Other machines connect to the router just fine through wired ethernet (xbox360 and linkstation mini).
I'll also post this in the mac mini section, but I doubt it is hardware related.
I have noticed the exact same issue.
At my office both wired and wireless network works flawlessy, I just plug in the ethernet cable and I instantly get an IP address from our DHCP network.
At home however I have noticed the same issue many other have reported. I use D-Link DIR-635 as a router with DHCP enabled for both the wired and the wireless network. If I connect to the wireless network, I will receive an IP and everything works. When using the wired network, the MacBook seems to refuse to use IP address assigned by the DHCP server, it uses a self-assigned IP instead (which of course does not work).
Is there any sollution to this? I highly doubt it is a router issue, in this thread I have seen various routers from different manufacturers, yet the same problem is reported. I have also never experienced this problem on any of my other computers, running different versions of Windows/Ubuntu.
Add another one to the list.
I have a MacBookPro3,1 that connects to WIFI no problem. It used to connect to ethernet when I originally bought it, however I've been using WIFI exclusively for the past 2 years.
Recently I had a need to connect via ethernet and it wouldn't work at home (apple airport router). I next tried connecting via ethernet at a friends house using a linksys WRT54G, no dice either. I have the computer in the lab today (University Network) and I get the same error. 3 different locations, 3 different routers, all same problem. It used to connect to home and university networks ethernet right away.
IP address assigned is 169.xxx.xxx.xxx - subnet - 255.255.0.0
no other info. It's showing up as connecting to the network, but unable to communicate with DHCP. It does work if I enter all of the information in manually.
At first I thought I had messed something up in networking preferences as I tend to play around with things alot. However I did a complete system format, and fresh install of OSX Lion and I still have the same problem, without any of my meddling around to confuse things.