Blinking ethernet light on cable modem?

TechnoScream · 29 Jul 2009 at 14:23

Hi all,

There were recent power outages in my area, and now that everything is back up and running, I have strange internet related issue.

I have an NTL cable modem connected to a wireless router via an ethernet cable. I do still have an internet connection but its has become slow and unreliable. I have noticed my ethernet light on the cable modem is now rapid flashing (should the constantly on) and think this has something to do with the problem.

anyone come across this before? I cant work out what would make my ethernet light flash when it should be constantly on?

Thanks in advance

PistolPete · 29 Jul 2009 at 14:31

Are you on 20Mb and have either a Ambit 100 or 120 modem?
If so, ring them up as they are swapping these out anyway.

Sp00n · 29 Jul 2009 at 14:32

Constantly on = no traffic

it's an activity light isn't it?

Skidilliplop · 29 Jul 2009 at 14:32

Normally Ethernet lights do blink with activity. Normally it's a worry if they're solid because it means no traffic happening.

Standard first steps apply to be honest. Power cycle both devices, check the cable between Check the configs on both i.e speed and duplex of the ethernet ports in question.

TechnoScream · 29 Jul 2009 at 14:44

Thanks for the replies so far,

I may be wrong but I really dont remember this light flashing before, the modem has separate download and upload lights which I understood are the only ones that should be flashing. The Ethernet Light on the modem flickers in snyc with port 1 on my router (which again I think should be constant on!) while port 2 stays constant on as I expect (Ports 3 & 4 are not used).

It is an old silver NTL modem (not sure of model as not at home) so I guess it could be on its way out.

I have powercycled both modem and router but that had no effect.

I think im on an 8mb connection

Skidilliplop · 29 Jul 2009 at 14:55

If you're on cable it'll be 10meg not 8meg. 8 Meg is indicative of ADSL lines.

Almost all status lights on ethernet ports flicker with activity. Usually the internet facing one doesn't flicker much because typically when browsing usuage is intermittent and if you're sat looking at the modem you're not on your PC using the link. I would check the cable to ensure it's not causing packet loss. A ping -t to google would possibly help.

TechnoScream · 29 Jul 2009 at 15:09

Skidilliplop said:
I would check the cable to ensure it's not causing packet loss.

I'll try a different cable out of interest

Skidilliplop said:
I would check the cable to ensure it's not causing packet loss. A ping -t to google would possibly help.

...can you run me through this?

Skidilliplop · 29 Jul 2009 at 15:11

go to command prompt, type ping -t google.co.uk <enter> watch for 5 mins and see what happens.

TechnoScream · 29 Jul 2009 at 15:50

Skidilliplop said:
go to command prompt, type ping -t google.co.uk <enter> watch for 5 mins and see what happens.

Will do this when I get home and post my findings, thanks

TechnoScream · 29 Jul 2009 at 17:31

bytes=32 time=102-115ms tll=244

..does that look correct?

edit* also your e right, after running a speed test it says my download is 10mbps ...my upload is 0.48mbps ..does the upload sound right?