Why does the data light on my cable modem keeps blinking?

TeenInternetAddict · Post by **TeenInternetAddict** » Mon Feb 12, 2001 8:08 pm

Hi, I have a surfboard SB3100 cable modem, and the data light won't stop blinking, though, i'm idle like going to the restroom, typing, etc.

Can anyone help me? I'm using a RR connection, and the blinking light is getting on the last of my nerves. I have tried everything, from moving the cable modem, to changing the coxial cable line.

Do i need another cable modem, contact my local cable company, or what? I'm using zonealarm, but it may be the firewall, or some hackers are trying to break into my pc..

TIA

Helen

crazyman · Post by **crazyman** » Mon Feb 12, 2001 8:17 pm

Originally posted by TeenInternetAddict:
Hi, I have a surfboard SB3100 cable modem, and the data light won't stop blinking, though, i'm idle like going to the restroom, typing, etc.

Can anyone help me? I'm using a RR connection, and the blinking light is getting on the last of my nerves. I have tried everything, from moving the cable modem, to changing the coxial cable line.

Do i need another cable modem, contact my local cable company, or what? I'm using zonealarm, but it may be the firewall, or some hackers are trying to break into my pc..

TIA

Helen

that's normal,once you have been to a site,the cookies are installed for on e thing,and yes sites you have been to and your modem still communicate,as long as you have firewall software you are just fine...

www.zonelabs.com go and get some free firewall software to keep you pc safe.

Indy · Post by **Indy** » Mon Feb 12, 2001 10:51 pm

I've noticed that sometimes with the sb3100s that if you have a continually active activity light that it could be noise on the cable line. One thing you might want to check is unplugging the modem, let it set for a minute or two, and then plug it back in. Sometimes some of the surfboard modems that I've dealt with will clear right up doing that power cycle on it...

HMS White Star · Post by **HMS White Star** » Mon Feb 12, 2001 11:10 pm

Hi, I have a surfboard SB3100 cable modem, and the data light won't stop blinking, though, i'm idle like going to the restroom, typing, etc.

It's mostly likely the Dhcp server pinging you to make sure you are alive, it's pretty funny when I have a data light blinking when both of my computers are off

Indy · Post by **Indy** » Mon Feb 12, 2001 11:12 pm

Is the activity light blinking constantly, almost like its on continuously, or is it just blinking every couple of minutes or so?

TeenInternetAddict · Post by **TeenInternetAddict** » Tue Feb 13, 2001 6:45 am

Originally posted by IndyOST:
Is the activity light blinking constantly, almost like its on continuously, or is it just blinking every couple of minutes or so?

That what the activity light does, blinks like it's on continuously, but I'm not surfing the web or doing anything. I'm using ZoneAlarm firewall protection.

MosDef112 · Post by **MosDef112** » Tue Feb 13, 2001 10:02 am

Your data (activity) light on your cable modem will blink all the time due to the shared nature of cable Internet infrastructures, whereas any other users connected to your node will also experience the same behavior with their cable modems as well. You don't have a dedicated switched connection to the Internet, but instead use an open port (your cable line) to access the net. This is best explained when compared to Ethernet dumb hubs. If you notice, in any environment whereas all nodes attached to a LAN with a hub you will find that whenever someone accesses a network resource, whether files or the Internet, all other nodes attached to the same hub will also show activity on their NIC's. This won't be true if the same nodes are attached to a LAN via a switch. This is due to the fact that, as dumb hubs do, cable infrastructures broadcasts all packets throughout any given node until they finally reach it's destination address, or your PC. This is really the most vulnerable security hole with respect to cable Internet access, anyone could easily find out your IP address and any open ports on your PC by simply using a network 'sniffer,' consequently making chances of any breaches to your systems more likely compared to any other dedicated Internet connections. The only safest way to approach this is to have a hardware or software-based firewall sitting between your cable modem and your PC. Furthermore, also making sure that no NetBIOS or file-sharing processes are available past your WAN connection is a good way to ensure security, a good software-based firewall will address this properly.

Peter D Meredith · Post by **Peter D Meredith** » Tue Feb 13, 2001 10:21 pm

Hum! I don't know about this!?! I have the same SB3100 sitting right next to me. Until I actually Upload this reply. I'm absolutely certain that the light will not blink. (I am watching it just to be sure)

Now on other occassions; like when I'm playing music using Sonique (which I allow to report usage statistics) the light will flash "regularly", but not constantly.

I do have a static IP setup and am using a Linksys BEFSR41. I guess it could be as HMS White Star suggests. But that seems a bit off as well. Unless TeenInternetAddict has programs running on her computer, in the background, that are trying to update or synchronize themselves with an Online server. There should not be constant / regular "activity".

Storm90 · Post by **Storm90** » Tue Feb 13, 2001 10:37 pm

I would look into the problem . I run a toshiabPCX100 and the only time its data light blinks is when I am sending info to my other computer or downloading, I had the modem you had and it kept doing that so my provider changed it. GoodLuck!

[ 02-15-2001: Message edited by: Storm90 ]

MosDef112 · Post by **MosDef112** » Wed Feb 14, 2001 11:54 am

*** In response to CannyOne ***

You said:

I do have a static IP setup and am using a Linksys BEFSR41.

You are using a router/switch sitting between your cable modem and your PC, this is why you don't see the broadcast traffic traveling across your cable modem's network. A router/switch will not pass packets through that aren't meant to arrive at your PC.

tekelberry · Post by **tekelberry** » Thu Feb 15, 2001 12:20 am

Try checking the ZoneAlarm log and seeing if anyone is requesting a port or something. If nothings in the log than its probably nothing. Don't worry about it. Try going to http://192.168.100.1 and check the status page. Post all that in here and well tell ya if its noise! BTW...just dont worry about it if none of this fixes it

TeenInternetAddict · Post by **TeenInternetAddict** » Thu Feb 15, 2001 12:47 am

Acquire Downstream Channel Done
Obtain Upstream Parameters Done
Establish IP Connectivity using DHCP Done
Establish Time Of Day Done
Transfer Operational Parameters through TFTP Done
Register Connection Done
Initialize Baseline Privacy Skipped

Is it cable noise or not? Judging by these old cable lines, it might be cable line noise, or i need to buy a new coxial cable at walmart.

Helen

Peter D Meredith · Post by **Peter D Meredith** » Thu Feb 15, 2001 2:25 am

To MosDef112:

Ok! I thought it might have some bearing on the situation. That is why I included the information. And you have educated me.

Thank you!

MosDef112 · Post by **MosDef112** » Thu Feb 15, 2001 7:42 am

*** In response to CannyOne ***

You're very welcome, I'm glad my input was useful to you.

MtCableman · Post by **MtCableman** » Thu Feb 15, 2001 9:35 am

You could also use MSDOS, type in "netstat -n" and see what ports are open. If you have all the browsers off and no other programs running there shouldn't be any open ports. If there is you could have a virus on the computer.

hoov · Post by **hoov** » Thu Feb 15, 2001 9:56 am

My Cable modem sends ARP broadcasts often that make the data light blink a lot. Like someone mentioned above, this is due to the cable network and the node that you are on.

MosDef112 · Post by **MosDef112** » Thu Feb 15, 2001 10:14 am

*** In response to MtCableman ***

That isn't always the case. There may be other applications running in the background requiring access to network resources, whether past the WAN link or not.

MosDef112 · Post by **MosDef112** » Thu Feb 15, 2001 11:32 am

*** In response to hoov ***

That may be also true, but if that is the case with you, then you may need your cable Internet company to look into your routing configuration. If your cable modem sends out ARP requests, then it isn't finding a router at their end or your particular subnet isn't added to one or more of the routers in their network. This can degrade your bandwidth over the course of time especially if demand picks up in your neighborhood.

hoov · Post by **hoov** » Thu Feb 15, 2001 11:41 am

[quote]Originally posted by MosDef112:

Thanks for the info, I will have to check with them.

MosDef112 · Post by **MosDef112** » Thu Feb 15, 2001 11:54 am

*** In response to hoov ***

You're welcome, I hope this helps.

jeffles37 · Post by **jeffles37** » Thu Feb 15, 2001 3:58 pm

Mine does hte same thing (RCA) looks like i'm always being pinged, although it started a month ago or so. Doesn't matter whether the comp is on/off.

dabeech · Post by **dabeech** » Fri Feb 23, 2001 10:27 am

It's true that a cable network is a shared medium, but the data light does not blink every time a frame hits your modem, MosDef. The cable modem is both a modem and a bridge. Therefore, the data light will only blink when your computer is sending/receiving data, not whenever there is activity in your neighborhood. Do not call your cable company because it is definitely not an issue with their network. Before you disagree with me, shut down your PC and you will see that your data light will only blink once or twice a minute, not constantly. Are you running Napster? If so, the data light will be pretty constant as others download songs from your PC.

Storm90 · Post by **Storm90** » Fri Feb 23, 2001 10:53 am

Why buy your own cable? call your provider and have them check your main drop. They do not charge for this. Plus what they install is better then Kmarts. Plus check your rj45 line from your modem. It may need replaced.Or as was said it could just be your provider pinging you. try a firewall if you do not have one and see if that helps.

MosDef112 · Post by **MosDef112** » Fri Feb 23, 2001 11:38 am

*** In response to dabeech ***

I'm not saying that the symptom definitely suggests broadcasts on that node, it can also be many other factors. Not that I'd disagree with you, but I've also seen what I've described happen. If the cable operator wanted to do the right thing, they would setup a bridged connection to their cable modem. This eliminates the need for the end users to have to ARP to any routers at the ISP end, whenever the default route isn't found.