dhcp problems

gabysbrain · n00b Joined: 30 Dec 2002 Posts: 4

Ok, this is frustrating. My cable company uses dhcp to configure the address. If I reboot the computer it can't get an ip address. If unplug the cable modem for about 10 minutes and then plug it back in then everything works fine when it brings up eth0.

I turned on debugging for dhcpcd and it never seems to get a reply to dhcp_discover. There is always a connection and the activity light on the back of the card and the cable modem are flashing so I think everything is ok.

I'm using cox high speed internet if that matters.

This is a replacement for my hardware router which crashed too often for my tastes (but never had a problem getting an address) so I want to run it headless and start up again in a power failure, so does anyone have any ideas what could be causing this?

jufoa · Posted: Wed Jan 08, 2003 7:45 am Post subject:

hmm. i had very similar problem with my cable modem. i did take a lot of time to get ip if at all. i removed the dhcpcd -k line from net.eth0 from the stop section. so that when rebooted it doesnt clear the cache and next boot tryies same values before fetching new ones.

gabysbrain · n00b Joined: 30 Dec 2002 Posts: 4

Actually I tried that too, but it didn't seem to work. I even tried hard-rebooting the computer (so the shutdown script was never called) and that didn't seem to work either.

Xenocide · n00b Joined: 08 Jan 2003 Posts: 5

Actually whats going on here is that your cable modem has memory of the MAC address on the card. If you're not aware what a MAC address is, its essentially a serial number for ethernet cards thats theoretically unique. Until you reboot the cable modem its attached to the computer it started with, or at least wont hand out another lease until a request from the same MAC address comes through. Basically your only hope in this matter is to either buy more IPs from your provider or set up a router in between you and the cable modem and proxy the connections. This is of course against their policy, which is why you shouldn't do it with a hub. Or you can suffer with rebooting the modem to get a new lease like I do, but I'm starting to wonder if they monitor this stuff and are planning out a secret swat team assault on my house as we speak.

keratos68 · Posted: Wed Jan 08, 2003 11:36 pm Post subject:

Check with your ISP, have they got BOOTP & DHCP set-up? Are others experiencing probs? I had this prob about 4 months ago, ISP was trying to reduce bandwith I reckon, but they nevre admitted to it. All of a sudden it started working but not until I placed the threat of cancellation and a refund !!!
_________________
Someone told me that "..they only ever made one mistake...."

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gabysbrain · n00b Joined: 30 Dec 2002 Posts: 4

Ok, I'll call them tomorrow. Hopefully they know what linux is. :wink:

How can they use both BOOTP and DHCP at the same time? Don't they both get my a dynamic address? And why would preventing me from getting an address on reboot help conserve bandwidth?

I was looking at the dhcpcd man page and it said that there's a switch for an obselete protocol (-r) and I tried using that too but it didn't work either.

Does anyone know what windows does? I bet they have their network set up to cater to those people and since you need to reboot windows about 5 times whenever you plug something into the computer I figure that should work. I don't have anything with windows on it here (or even something that can run it).

Thanks for everyone's help!

keratos68 · Posted: Thu Jan 09, 2003 8:17 am Post subject:

I'm not positive that this IS YOUR problem, but I had the same prob. BOOTP is the basis of DHCP, they are configurable at the server end, I used to run my web server with NAT,DNS,BOOTP,DHCP so on, but gave up due to constant config problems ... its a full time job!!!

I just let someone else host it now !!!

Maybe others reading this thread can suggest alternatives ?

BTW, tread careful with "Linux" with your ISP , some use it for the excuse that things aren't working - had experience of that too - or that they "Don't support Linux". Use creative questioning to probe them first!!!

Perhaps just mention that you keep loosing you IP address and upon a reboot it takes 10 minutes or so it to be assigned/reassigned.
_________________
Someone told me that "..they only ever made one mistake...."

...and that's when they said they were wrong!!