Arch Linux

sveinhal

Member

Registered: 2008-10-24

Posts: 3

DHCP getting a lease, but times out on availability check

Hi, all!

I'm new to this forum and to Arch Linux. I'm coming from a FreeBSD background, but recently switched my laptop and workstation to Linux (Arch). I'm however, still using FreeBSD on my DHCP server.

When requesting a lease, I get this:

[root@weld:~]$ dhcpcd -n eth0
eth0: dhcpcd 4.0.2 starting
eth0: broadcasting for a lease
eth0: offered 10.0.0.176 from 10.0.1.1 `mirrorball'
eth0: checking 10.0.0.176 is available on attached networks

It then times out, and uses an IPv4ALL address instead of the offered address.
What is this availability check? Should I be getting some response from my DHCP server on this?

Thanks in advance for any insight into the problem!

bender02

Member

From: UK

Registered: 2007-02-04

Posts: 1,328

Re: DHCP getting a lease, but times out on availability check

I think it tries to check if there is some other computer on the network with the same address - I think it just sends out some packets for <offered_ip> and looks for a response.

What seems unusual to me is that you're offered .0.176 and the server is .1.1 - so your server routes 10.0.0.0/16 ?

sveinhal

Member

Registered: 2008-10-24

Posts: 3

Re: DHCP getting a lease, but times out on availability check

I think it tries to check if there is some other computer on the network with the same address - I think it just sends out some packets for <offered_ip> and looks for a response.

What seems unusual to me is that you're offered .0.176 and the server is .1.1 - so your server routes 10.0.0.0/16 ?

Nope, it's /23. I have all the static address on 10.0.1.x and the dynamic ones on 10.0.0.x.

I do however, have other clients with no problem at all, and the DHCP server do offer an address. How does the client check for other machines on the network with the same address? Does it send echo packages (ping)? This just recently became a problem, I don't think I changed anything on either the server nor the laptop.

However, we also have an OS X laptop on the network, which also has problems getting a lease (although it's a little more vague on the error message). Another OS X laptop again, has no problems at all. Also a Windows client I have show no problems.

??

bender02

Member

From: UK

Registered: 2007-02-04

Posts: 1,328

Re: DHCP getting a lease, but times out on availability check

I don't really know how does it do the check. I tried to google a bit, but I guess my googling skills aren't what they used to be...
I just remember that once I was messing around with my router, I set up a range for dhcpd which included an address that was statically used by one of the other computers; and dhcpcd bailed out in that 'checking availability' with the complaint that the IP is already taken.

But if your server filters some traffic (like udp), then that might be the problem. Just guessing.

You could try to use dhclient, just to see if it goes through.

Last edited by bender02 (2008-10-24 12:38:33)