3CRWER300-73 -Failing to get DHCP from ISP (cable)

[genedunn]

I have cable internet service, coming into a Motorolla SB5100, which I then connect to my 3COM 3CRWER300-73 to service multiple devices (PC's, printers, game consoles).

Over the past 30 days, I have been getting disconnected 1-4 times per day.  To restore service I can (usually) execute the following process:


1)  Restart cable modem


2)  Login into router administration, go to "Status and Logs"


3)  Release DHCP


4)  Renew DHCP

Usually this works, although it sometimes requires multiple iterations of "Renew" before the router will get a valid DHCP from the ISP.  Occasionally, it will get a clearly bogus IP address (192.168.1.11) from somewhere (itself?  the cable modem?).  Today, I was NEVER able to get DHCP from the ISP.

When I call the ISP and talk to their support team, they invariably have me connect the cable modem directly to my PC, then they reset the cable modem remotely a few (1-3) times, have me reset it by unplugging and replugging, then my PC will get DHCP.  I then reconnect to the router and typically cannot get DHCP, so the ISP will declare "See, its your router," and tell me to contact 3COM.  I'm not buying that.  Later, I can reset the modem again, connect to the router, and eventually get DHCP, but this sequence occurs again within 24 hours.

Any thoughts?  I can provide a sample log for the period if needed, but generally it says " Could not find DHCP daemon to get information".

Thanks for your help.

PS:  I have installed the latest firmware (v1.11, i think)...

This message was edited by genedunn on 8-12-10 @ 10:37 AM

[hyperlisk]

Looks like modem has web configuration pages. Can you access them? If yes, then we can go step-by-step through the configuration.

[genedunn]

The ISP finally sent a service tech out yesterday (13 AUG 10).  He replaced the cable modem and it has been stable since.  If it starts failing again I will re-post.