I am currently using m0n0wall on a soekris net4521, 1.2b3 firmware.  I
have been having regular breaks in my internet connection (ADSL
provided by Force9, PPPoA).  Each time this occurs I see the
following, or something similar, in the logs:

==========

Feb 10 14:41:56
dhclient: No working leases in persistent database - sleeping.

Feb 10 14:41:56
dhclient: No DHCPOFFERS received.

Feb 10 14:41:54
dhclient: DHCPDISCOVER on sis1 to 255.255.255.255 port 67 interval 2

Feb 10 14:41:42
dhclient: DHCPDISCOVER on sis1 to 255.255.255.255 port 67 interval 12

Feb 10 14:41:21
dhclient: DHCPDISCOVER on sis1 to 255.255.255.255 port 67 interval 21

Feb 10 14:41:08
dhclient: DHCPDISCOVER on sis1 to 255.255.255.255 port 67 interval 13

Feb 10 14:40:59
dhclient: DHCPDISCOVER on sis1 to 255.255.255.255 port 67 interval 9

Feb 10 14:40:55
dhclient: DHCPDISCOVER on sis1 to 255.255.255.255 port 67 interval 4

Feb 10 14:40:55
dhclient: DHCPNAK from 10.0.0.2

Feb 10 14:40:55
dhclient: DHCPREQUEST on sis1 to 10.0.0.2 port 67

Feb 10 14:40:08
dhclient: bound to 212.159.xxx.xxx -- renewal in 47 seconds.

==========

The reason my internet connection drops is that m0n0wall receives
DHCPNAK from 10.0.0.2 (the modem).  To reconnect I have currently been
entering "route delete default" and "route add default -interface
-link sis1" in exec.php after which the m0n0wall gets its IP address
again and everything is fine for a while (around 15 minutes) until it
happens again.

Does anyone have any idea why this could be happening?  I've tried
adslnation's support forums but they are currently down - at the
moment I don't know whether the problem is with my m0n0wall, my modem
or my understanding of how to set everything up.

Thanks in advance,

Tim