Why is my WAN access light always blinking?

[Modular]

Is it a plethora of port scans, IP pings, etc. that cause this? My cable modem is always showing activity and my routers WAN light is always blinking, but the individual LAN connection lights only blink when in use.

I was talking with my Father in Law who said that those were all port scanners and computers pinging my network looking for a way in. While I generally highly regard his input in computer/network related topics, he does have a way of embellishing on the truth at times. So what is it that causes the WAN and cable modem to be constantly in use?

 

[Fardringle]

Your father-in-law is correct.

 

[Shaotai]

download a program that lets you watch traffic, like a firewall and/or sniffer and plug directly into the WAN.
You'll be surprised!

 

[JackMDS]

It is a Cable Internet phenomenon.

DSL comes in through your dedicated telephone line,

Cable Internet is organized in nodes. I.e. you are on the same line with many of you neighbors. The constant blinking represent the collection of signals that are generated by multiple users being on the same line.

 

[spidey07]

It's broadcast traffic. It's normal.

 

[ding5550123]

It is because your ISP uses a switch that repeats the signal to all clients, so your router is getting your neigbors Internet requests, but rejecting them because they are not addressed to your network.