PDA

View Full Version : Strange behaviour of broadband when modem on a multiplug


rimbaud
19-08-2007, 22:12
Hello all

I have been a Telewest broadband customer for five years or so, and recently moved just up the road (still ex-Telewest) and kept my broadband.

The nice man came round and installed the service, I plugged my wireless router in and everything worked as usual. Problems started last week when the Virgin Media service went down for a day and a half, and when it was supposed to be fixed, my connection had still not come back up.

It turns out the issue is my cable modem won't make a new internet connection when it is on a four plug extension lead! In between the installer chap coming round and the service going down, I had put all the rest of my office stuff on the extension lead, just as I had been doing for years with no problem. As you can imagine, this was very frustrating, but at least I now have an internet connection if I plug my machine directly into the modem.

However, my wireless router is now unable to ever make a connection to the internet, never gaining an IP address. I have logged into the router and tried to get it to work via DHCP, but it always says it can't find the server (yes I have plugged the cable from the modem into the WAN socket). The Cable modem is definitely happy and the lights on the router are as usual.

My worry is that I have a dodgy cable signal (as indicated by the fact that the modem won't connect when on a four plug) and this is stopping the router working, or does the router get its IP from the modem? Any help would be much appreciated.

Jon

Details below:

My main machine: Ubuntu Linux (Feisty) laptop
Laptop: Mac Powerbook
Modem: SB4100 Surfboard
Router: Buffalo Air Station G54
Area: London NW1 (ex Telewest)

Downstream Value
Frequency 339000000 Hz Locked
Signal to Noise Ratio 36 dB
Power Level 8 dBmV

Upstream Value
Channel ID 2
Frequency 34000000 Hz Ranged
Power Level 34 dBmV

Stuart
19-08-2007, 22:39
You do need to reboot the modem if you switch devices plugged into the modem.

rimbaud
19-08-2007, 22:46
Hello, thanks for the reply

Yes, I have rebooted the modem and given it quite some time to settle down.

Jon

rimbaud
20-08-2007, 18:48
Hello

I finally solved the problem, so I thought I'd tell you all.

I hit the factory reset button on my router, and although it didn't reset the router to factory settings at all(!), it instantly worked perfectly.

That cable service outage really screwed my hardware up...

davedefeet
20-08-2007, 22:03
Vicky Pollard (The manager of Technical Support Centre Swansea) says "Yeah but New but yeah but new but yeah, rimbaud fingered his router and it came on, but he didn't know he put it in and out of his modem before the router, before that, yeah but new but yeah he's got to do it that way otherwise it won't come... on

In other words, after an outage, one must do what my ex-colleagues in India call a "Logical Reboot" That is turn the power OFF on the router AND modem, then turn on the modem, wait until it connects (about 2 minutes) THEN turn your Router on, this fixes most issues when the router gets no WAN IP or an invalid WAN IP

As for an outage screwing up your equipment? please qualify this comment with a logical explanation!

4 way (or more) socket extensions, sometimes cause issues due to badly connecting pin/socket or dips/surges on the AC, try another extension, preferably one that is new and NOT from the POUND SHOP!

Yeah? New?

I used to work for Virgin Media, but I'm better now.