Router has trouble getting IP, computer gets IP instantly

PV9685

Distinguished
Feb 25, 2009
27
0
18,530
Hello all,

I am using Charter and have been at this location for several year. All was well until they added one of those "walled gardens" like Comcast uses.

When the cable modem comes on, and the wireless router is turned on, the router has trouble getting it's dynamic IP from the network. If I plug my workstation directly into the cable modem - bingo - IP comes very quickly every time.

I have tried multiple cable modems and multiple wireless routers. I use MAC cloning otherwise Charter doesn't give an IP ever. I have tried using both Unicast and Multicast for getting the IP but, it seems like the routers request/respond to DHCP differently than a Windows PC (Vista and 7) does.

Anyone know if a computer and router use DHCP differently? It is weird because when there is a power outage things generally come back on without a hitch. Though if I unplug/plug the devices manually it takes me half an hour or more to get an IP most times.
 

rstration

Distinguished
Jul 10, 2011
1
0
18,510
I have had the same issue and have tried a combination of 6 routers and 3 cable modems without success. The issue seems to have been around for a while and is unique to charter, yet few of their techs are aware or admit it.

Actually, I borrowed a verizon/westell 7501 router and it is the only router that seems to be able to get the dhcp properly and reliably. The issue is that router has a problem with multiple SIP streams, so when I get call waiting it knocks my phone off. One problem solved, another one created. The other routers don't have the SIP issue, but they keep losing the connection when the IP lease expires. Charter's lease time is especially short so you could lose your connection within the same day without doing anything.

PLEASE if anyone has a definitive solution, please post it. Maybe someone can get it through Charter's head(s) that the issue is unique to them, so it's unlikely that it's other hardware problems.

see this thread
http://www.techsupportforum.com/forums/f135/dhcp-problem-with-charter-modems-322842.html