dhcpcd - ok at work, fails at home

TheHistorian · n00b Joined: 16 Jul 2005 Posts: 27

I built a gentoo laptop at work, and everything is fine. I unplug it, take it home, and plug it into my cable modem, and dhcpcd fails. For now, I'm dealing only with ethernet at both locations (I'll work on wireless later).

Stuff I realized/tried:

I have another machine at home that works through the cable modem.

dhcpcd broadcasts using the last IP address it had, so I renamed the dhcp related files in /var/cache and /var/lib/dhcpc

/etc/conf.d/net contains:

iface_eth0="dhcp"
dhcpcd_eth0="-HD"

(I've tried a few different combinations of flags there)

boot time looks like:

Starting eth0
Bringing up eth0
dhcp
Running dhcpcd ...
ERROR: Problem starting needed services.
"netmount" was not started.

/var/log/dhcpcd.log shows:

Jul 16 15:46:34 localhost dhcpcd[5297]: timed out waiting for a valid DHCP server

My provider is pretty big (Comcast) so my gut tells me that they are using DHCP and not some other wacky protocol, but I'm pretty much out of ideas.

Any thoughts are appreciated.

Thanks,

Steve

katsiki · Posted: Sat Jul 16, 2005 8:12 pm Post subject:

Most cable providers only allow one device to be connected directly to the cable modem. They may only allow one device to receive a DHCP address from their DHCP server. If this is the case, you may need to use a router, in order to be able to connect two computers to the network at the same time. A router partitions the wide-area network (WAN) from the local-area network (LAN), isolating an internal private IP address space to be used among several computers and other network devices. Are you using a router or a switch?

If you are using a router, is it configured to receive its own DHCP address from your cable modem provider, and does it have a built-in DHCP server to issue a private IP addresses to your home computers?

TheHistorian · n00b Joined: 16 Jul 2005 Posts: 27

*slaps forehead*

Gah!

I knew it was going to be something boneheaded like that. I've been so frazzled with moving, getting things set up, and starting a new job, that obvious things like this are eluding me.

One router unpacked. One problem solved.

Thanks!

katsiki · Posted: Sat Jul 16, 2005 8:45 pm Post subject:

You're welcome! Happy house and computer warming!

-neX- · n00b Joined: 29 Apr 2005 Posts: 45

just a note, unless your isp does hard bindings in dhcp; you can usually just unplug the modem with your interface down, plug the modem back in, wait for it to sync back up with the cable network, and then dhcpcd your interface. after that, you should have a shiny new ip arp!

hopefully this will avoid a couple of calls to support to modem arps!