Hi! I've been using my cable modem with Linux (Slackware 8 base with 2.4.20 kernel and other updates by me) with no problems at all. DHCP works just great and I've never experienced an easier time connecting to the Internet.

Well, except for today. Today for _some_ reason my connection was busted and I couldn't even ping my default gateway (I have only one machine connected to the cable modem and no external routers or anything).

So, I called Comcast and part of their routine had me reboot. So, I rebooted and when the system was booting I nocticed a '"DHCP_NAK" server response received' message appear after dhcpd started up. I logged in and ran "ifconfig" and saw I had been assigned a new IP address.

Now, my question: if the lease on the IP address I'm assigned expires, must I do anything to get the newly assigned IP address configured or should dhcpd do that for me? I don't boot my machine much at all (the uptime before I rebooted today was about 36 days or so) and this is the second IP address I've received since Comcast took over from AT&T.

I'm not sure what will happen the next time my lease expires. Last night, my Internet access was working just fine. Then this morning, nothing... at least until the reboot.

What's going on? Where can I get more info on how this kind of config works?

Thanks in advance for your time and assistance!

Peace.....

Tom

the dhcpd does the work for you. you dont have to reboot.
if you check the dhcpd leases file, you will see that dhcpd renews the lease after a fixed time which is called the default lease time specified by the comcast dhcp server, you may get the same ip but the lease will be renewed automatically after the default lease time. that time maybe something went wrong.

check your '/var/log/messages' and grep for 'dhcpd' then you will see all the lease renewals

dhclient / dhcpcd && cable modem
Architecture 1 : X86
MandrakeLinux Version Mandrake Linux 9.1 (Bamboo)
Subcategory Networking *
Question text
This is not a question but instead a valuable answer. I\'ve worked my tail
off the last two weeks trying to get Mandrake 9.1 and dhclient / dhcpcd to
work with my cable modem.

I found TONS of people with the exact same problem on the internet using
Google, Mandrake Club, Mandrake Expert, and even Redhat\'s newsgroups. But I
found no answers. So now that I have the answer, I want it spread FAR AND
WIDE so that no one goes through the hell that I just went through.

My problem was very well described by others especially:

http://www.mandrakeclub.com/modules.php?op=modload&name=Splatt_Forum&file=vie
wtopic&topic=7486&forum=10

and

http://www.mandrakeclub.com/modules.php?op=modload&name=Splatt_Forum&file=vie
wtopic&topic=7486&forum=10

and

http://www.mandrakeexpert.com/showarchive.php?arc=62608


My only additions are as follows: The problem is not fixed by changing
distributions and using Redhat, or Slackware, or Suse. They all have this
problem. It also doesn\'t matter if you use dhclient or dhcpcd or pump.
(Though pump is a little nicer.) They all have this problem.

Secondly it\'s not just Mandrake 9.1 that has the problem. My old box had
Mandrake 6.2 and, although it worked for three years without too many
problems, it often completely hung and crashed when I tried to fetch an IP
from Comcast\'s DHCP server.

So the answer? The answer to my problem was the cable modem. The old model
\"Tail Fin\" aka \"Shark Fin\" aka 3Com POS is not friendly with linux.

My old cable modem had very old firmware and although it is possible to
upgrade firmware, Comcast put a password on the SNMP connection. So that
option was not open to me.

I lease my modem so I had the wife march down to Comcast\'s office and demand,
(she\'s really good at that :-), a new modem. I ordered her to demand either
a Surfboard (Motorola) or any RCA model. Comcast explained that they didn\'t
have any new modems and she had to accept whatever they give her. Secondly
they said that the Surfboard modems won\'t work \"in my area\". No clue why.

Well the wife went off on the creep. And voila. I\'ve got an RCA DCM305
modem and it works. No hitches. No problems.

Please please feel free to email me if you\'ve got this DHCP problem. I can
help.

-Ed.