Comcast ( 
AT&T Broadband), 
Time Warner Road Runner Cable, 
Shaw in
Western Canada, 
Vidéotron Québec, 
Rogers Cable in Eastern Canada,
Delta Cable, 
Insightbb.com, 
Swedish ComHem.
Above ISPs use user-friendly DHCP servers, jump to success below.
Some Cox Communications
networks and
Optusnet in Australia:
login as "root", choose
(3) "Package
Settings", choose (3) dhcpc then (1) dhclient.conf, edit one line:
send host-name "keep-your-isp-happy" (see diagram) and delete the # at the
beginning of the line.
replace "keep-your-isp-happy" with your own
identification code.
Your identification code should
be given to you when you signed up for
Internet service (still stuck?)
Ctrl-S and Enter to save the changes. Ctrl-C to exit editor.
q(uit) twice to get back to
main configuration menu
choose (B) backup, Choose (6) dhcpc to save it to the floppy.
Power down, wait 10 seconds, then power up your cable modem, wait until the cable modem becomes "stable".
Reboot your LRP firewall after the cable modem is "stable".
and
some
Cable
Modem
Cox, 
Telewest, go to your ISP's web site
to register your MAC address
(catch
22) (how).
Telus BC: go to this web site to register
your MAC address.
NTL: Inform you ISP of the MAC address (of eth0) and wait 4 hours,
reboot the LRP.
Charter Comm Maryland also requires you to let them know
your MAC address. InsightBB also requires you to let them know your MAC
address through some magic.Or, contact your Internet Service Provider's
technical-support, inform them of your new Ethernet adapter,
give them your new MAC address (of eth0) for activation. Some ISP just love this
activation ritual to annoy customers.
Or, if you have registered a MAC address with your ISP, or you
know the MAC address of the network card
of a Windows box in your house this was successfully connected to your
ISP, you can fake the MAC address of your Ethernet card (eth0) to
declare itself as having another MAC address. To fake the MAC,
type
ae /etc/init.d/network, add four lines to it. Ctrl-S and Enter
to save, Ctrl-C to exit, lrcfg, b
for backup, choose (2), q twice to finish. Reboot the LRP. Thanks
to Peter Barry of Christchurch, UK 
for this tip.
After some time (minutes or hours), your new MAC address should become activated. Reboot the LRP to acquire a new IP address. It may require a power-down/power-up sequence on your LRP as part of the torture routine.
MAC
address
Power-down/power-up the cable modem / ADSL modem. Wait until the cable modem / ADSL modem becomes "stable". Then reboot the LRP firewall. If you pass the torture test, you will be able to "ping" to the outside world.
login as "root" (no
password needed)
Type q
to drop to the # prompt, at the #
prompt:
ping one of the friendly www web servers
e.g. ping
www.attglobal.net
(many www servers reject pings to reduce the effect of DoS attacks, in that
case, try other www servers)
You should see replies to your pings like
this.
Ctrl-C to stop the pings from running forever.
