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Level 1

1 points

Ethernet DHCP not getting IP address, but DHCP with manual address works

So I've spent hours looking through forums and trying to find an answer for this. I'll try and be as specific as possible.

My wife's new (2months) 13" White MacBook has recently lost the ability to get an IP via DHCP from our university network. It gives the self assigned IP 169.254.97.179.

My own MacBook Pro 13" can connect fine and all the network settings are identical on both machines. As are Firewall settings.

The weirdest thing and probably most interesting for ruling out all kinds of things is: if I use the DHCP IP address assigned to my MacBook Pro in the original MacBook(DHCP with Manual setting, after disconnecting the former of course) it connects instantly so there is no hardware issue here or other internet issues. (both machines can connect wirelessly to the internet with no issues.)

I have repaired permissions and zapped the PRAM to no effect.
I have deleted and recreated the *.alf.plist in /Library/Preferences, to no effect.

Basically what could prevent DHCP assigning an IP to one computer but having no problem with all other computers. I cannot get access to the router as this is a university network, but since other computers work fine it isn't a router issue.

I throw myself at the mercy of you mac gods.

Message was edited by: spaceman79

Message was edited by: spaceman79

MacBook 13" 2010, Mac OS X (10.4.6)

Posted on Aug 16, 2010 8:21 PM

23 replies

Jan 4, 2012 6:56 PM in response to spaceman79

This thread suggests removing the network services and plists, then rebooting and readding them:

https://discussions.apple.com/thread/2268121

Edwardo7

Level 1

0 points

Feb 7, 2012 8:30 AM in response to spaceman79

I have the same issue with my MacBook. Wifi works, but my wired ethernet port won't get an IP address from DHCP and self assigns 169.x.x.x. After reading this thread and getting mine to work, here's my guess at what's happening. There is poor communication between my mac and the dhcp server when the address up for renewal is already taken, eventually timing out. Maybe the Mac doesn't deal well with rejection or the dhcp server isn't good about suggesting an alternative. Apparently Windows PCs, as much as I dislike them, are more tolerant about this sort of thing. This can be resolved by configuring the DHCP sever to assign a fixed IP address based on the Mac's MAC address. This is what I did, and it worked like a snap. Manually configuring would have worked too, but this way I don't have to worry about DNS servers changing, etc. If you don't have the ability to change the server's config, other resolutions might include some of the recipes described in this thread, which amount to various ways of erasing the Mac's memory of what address it wanted to renew.

Dec 5, 2012 4:53 PM in response to Edwardo7

Yet another one having the same issue.

I have one iMac in the office that wont get the DHCP details, I manually configure it and it works.

I have tried booting it from a a clean install, no joy. I have a NetBoot server running, I hold down N on boot and nothing happens.

Dec 5, 2012 5:04 PM in response to paulfromburwood

And like that I have it working, I reset the SMC and it worked

http://support.apple.com/kb/HT3964

Oct 12, 2014 7:33 AM in response to Edwardo7

I have the same problem (macbook pro mid 2012).

I go to Settings>Network>Ethernet>Advanced>Proxy, uncheck everything, and delete everything in the text box.

Now ethernet is working ok and get DHCP address correct .

Jul 15, 2016 5:37 AM in response to spaceman79

I have the same problem with my (2008?) Mac Pro.

WiFi and Ethernet2 work fine, but Ethernet1 gets a self-assigned IP.

I've checked and cannot find any settings different between Ethernet1 and Ethernet2.

Also, maybe worth noting, if I reboot, I get a DHCP-assigned IP for Ethernet1, but it loses it again after a few hours.

appreciate

Level 4

1,278 points

Jul 15, 2016 7:27 AM in response to spaceman79

An apple article is there : OS X El Capitan: Choose a manual IP address or use DHCP

Nov 7, 2016 10:11 PM in response to spaceman79

I had the exact same problem after I upgraded my windows 2008 DHCP server to Windows 2012 R2 server the 2012 upgrade messed up the DHCP bindings:

It the DHCP server is a windows server check the DHCP server to NIC binding , it should only bind to a NIC that has a local/internal IP address assigned, if the binding is to a Public Static IP, Macs will never connect.

Ethernet DHCP not getting IP address, but DHCP with manual address works