[TriLUG] DHCP Problems and a Network Tap

[Sean Alexandre]

On Sun, Feb 16, 2014 at 07:54:57PM -0500, John Mitchell wrote:
>    Are you giving the firewall enough time? I recently changed my router to
> a dd-wrt/WRT54G and was having problems with it getting an IP address from
> TWC. I would use the old D-Link and it would connect very quickly (less
> than 20 seconds). I finally realized The dd-wrt needed about 60 seconds to
> connect. Once I left it alone (Duh!) it did OK.

So just leave it on for the day and see what happens. That's worth a try, thanks.

Right now I'm seeing these kinds of messages from dhclient, over the course of
a minute or so. Then it sleeps. 

DHCPDISCOVER on eth-wan to 255.255.255.255 port 67 interval 8
DHCPDISCOVER on eth-wan to 255.255.255.255 port 67 interval 7
DHCPDISCOVER on eth-wan to 255.255.255.255 port 67 interval 15
DHCPDISCOVER on eth-wan to 255.255.255.255 port 67 interval 9
DHCPDISCOVER on eth-wan to 255.255.255.255 port 67 interval 9
DHCPDISCOVER on eth-wan to 255.255.255.255 port 67 interval 13
No DHCPOFFERS received.

The laptop on the other hand, gets a lease after the first or second
DHCPDISCOVER.  Both the laptop and the firewall are Debian 7. Even more
interesting, the firewall can get a lease if I plug it into my OpenWRT router.
It's just having trouble when connected to the cable modem.

I've checked all levels of the DHCPDISCOVER message (from Bootstrap Protocol
down to Ethernet,) to compare them to what the laptop's sending and they're all
the same, except for some timing fields and the Transaction ID.