Telephony/Cable modem trouble in Mandriva 2006.0
 

Hello.

Recently a friend of mine subscribed to Comcast's digital telephone service. He had been using their regular Internet service previously, and it worked fine in Linux with his original cable modem. However, Comcast switched his modem to an Arris TM402P/110 telephony modem, and that's when the trouble started.

His phone service works fine mostly, but the Linux box refuses to get an IP address using the new modem. He has no router, nothing particularly non-standard at all--just one computer connected to the modem via the Ethernet interface. I use an almost identical configuration to his (except that I'm running Mandriva Cooker which has a few later releases of some things and I use a different high-speed provider and modem), so I brought my machine to his place to see if his telephony modem would work with mine...and no such luck. My machine used to connect without difficulty at his place with the old cable modem he used to have, and my machine worked fine again with my provider when I brought it back home, but not at his place with the Arris modem.

He's been around and around about this with Comcast tech support, and they finally sent a technician with a laptop running XP. The technician could bring up a connection through XP and that seemed to work, but Linux still won't grab an IP address.

We've tried the usual simple things--resetting the modem (both from his end and having Comcast send a reset signal), power-cycling the modem, different Ethernet cables, etc., and nothing we've tried has worked. The strange thing is, his DHCP configuration used to work fine, as I said--This only started once the new modem was installed, with no change in configuration.

Is it possible that the Arris modem requires some sort of proprietary initialization procedure that XP does but Linux doesn't, or could we be overlooking something very simple? (hoping it's the latter case...)

I did notice that Arris claims on their site that their modems don't support USB connections in Linux, though we've been using Ethernet rather than USB anyway, so I'm not sure if that's even relevant.

Right now I'm at home, so I don't have his system here to capture ifconfig output, etc., but in the next few days I can put that info on a floppy.

Sorry for the long post. We're totally stumped, and any info is appreciated.

Thanks for your time.
--Andy

Problem solved!
 

Hello again.

My friend discovered that the trouble was that the modem needed to be reset _while_ the computer is on. His connection is now up and working fine with the Arris modem. I'm glad it turned out to be something simple!

Take care,
--Andy