ugh ethernet is messed up on powerbook

[orijinal]

my ethernet connection keeps saying:

built-in ethernet is currently active. built-in ethernet has a self-assigned ip address and may not be able to connect to the internet.

it keeps assuming this 169.asdfasdf ip. for a few moments it'll go to the real 10.asdfasdf ip that it should, meaning it can connect to the net, but 99% of the time it has the 169.asdfa address.

it is connected to a switch, but even if i plug the ethernet directly from the jac, it still does this.

i even reformatted my powerbook and it is still doing this.

my PC in the room, and roommate's laptops work fine when connected with their ethernet, what is going on!?

 

[Blackheart]

Sounds like a hardware problem with a bad connection of the ethernet jack on the powerbook. Call up Apple for a repair.

 

[aquajet]

Try connecting your mac directly to your modem, and then cycle power on the modem.

 

[orijinal]

connected to university dorm ethernet, can't

 

[aquajet]

Have you tried speaking with the support staff at your university? Maybe they can help.

 

[ElectricSheep]

Could be a faulty jack or cable. It could also be some bad mojo between OS X getting timely DHCP updates from your uni's DHCP server.

Try forcing the interface to request a DHCP packet. You'll need the Terminal for this one, as the System Preferences just doesn't seem to make this happen 100% of the time.

In a new Terminal window, first clear the ethernet interface of any existing settings.

sudo ipconfig set en0 NONE

Next, reset the ethernet interface to use DHCP.

sudo ipconfig set en0 DHCP

As soon as you issue this command, your powerbook will send out a DHCP request. What should happen is that a DHCP server (typically the local router) will see that request and reply with information your PowerBook will use to configure the ethernet interface to get on the network.

Wait a few moments (like 30 seconds or something), and see if you got a DHCP packet back:

sudo ipconfig getpacket en0

If the above command produces no output at all, then for whatever reason you got no reply from the DHCP server. I know from the uni that I attended, they required one to register their computer's MAC address before allowing access the general network. If you don't register your MAC address, the routers either didn't respond to traffic coming from your computer, or would reply with a highly restrictive DHCP packet.

 

[orijinal]

ok, now i am thinking that it is the network.

i plugged into a different ethernet jack elsewhere in the campus and it worked, and i plugged into an illegal lan that was setup in my building and it worked. however when i plugged directly into the ethernet jack in that same room, i got the 169.asdf ip.

i have a feelig it has something to do with my dorm's network, but the guys are e-mailing me saying that it isn't on their end.

i don't know what to do!

oh, btw there is a system in our dorm where when you have to register your mac address to get the IP's, and yes my mac and pc are both registered. i noticed that this problem started happening when i recently added my PC again to the network (i had it set up before, and everything was fine, didn't use the PC for a couple months but am now using it again, and now everything is fudged up).

any network wizards able to get an idea??

 

[ElectricSheep]

ok, now i am thinking that it is the network.

i plugged into a different ethernet jack elsewhere in the campus and it worked, and i plugged into an illegal lan that was setup in my building and it worked. however when i plugged directly into the ethernet jack in that same room, i got the 169.asdf ip.

Both of those cases would have connected you to a different router.

i have a feelig it has something to do with my dorm's network, but the guys are e-mailing me saying that it isn't on their end.

Methinks its something to do with your dorm's network as well. For whatever reason, DHCP requests just aren't getting to a DHCP server from your PowerBook when connected on that network.

i don't know what to do!

oh, btw there is a system in our dorm where when you have to register your mac address to get the IP's, and yes my mac and pc are both registered. i noticed that this problem started happening when i recently added my PC again to the network (i had it set up before, and everything was fine, didn't use the PC for a couple months but am now using it again, and now everything is fudged up).

any network wizards able to get an idea??

What happens when you remove the PC from the dorm network, and just connect your powerbook?

 

[orijinal]

well, i just removed my pc from the network as it is, and now i get a constant 64... address, so i guess i'll just leave the pc off my account. i'll try to add it to my roommate's account, maybe it'll work.

but yeah the system has to be fudged up