Question About Lights on Updated Comcast Modem

I didn't know where to post this question, please excuse me if it's in the wrong forum. I have a windows 10 desktop with Comcast internet service.

They sent me a letter awhile back that I needed to update my old modem with their new one. Yesterday I went to their store and connected and activated it, following the instruction booklet. I'm using an ethernet connection to my computer.

Since I installed it, there has been two lights continuously flashing, the 2.4GZ and the 5GZ. I believe on the set up screen I chose the 2.4GZ, as the guy in the store said it didn't matter which one I chose, but generally they use the 2.4.

I posted on the Comcast customer support forum because I really would like to avoid involving a tech if I don't have to. I never got a reply from a Comcast employee, only one from an 'expert' there who said it's nothing to worry about.

I don't think it's okay, because on my old modem no lights were flashing. I don't know much about computers, but I thought someone here could give me their thoughts on this.....thanks.

2 g is a longer range wireless 5g is the new much fast but shorter range normally they only flash when in use

Since your computer uses Ethernet, you may not realize that what Comcast gave you is a combination modem and WiFi internet router. The 2.4 ghz and 5 ghz lights are the WiFi channels. The question is what did you set up for security for the WiFi channels? Did you give the WiFi network a name (SSID) and did you set a password for it? Anybody with a WiFi device within range can see your network (in most setups) and if a password is not set, they can connect to your internal network. Both 2.4 ghz and 5 ghz channels are active - it's a dual band WiFi router/modem combination.

Also, you may not know that by default Comcast includes a guest network on your WiFi. It's usually called xfinitywifi. This allows any Comcast customer within range of your router to connect to Xfinity (Comcast) internet using your cable connection. The guest networks are supposed to be separate from your own internal network.

For this reason, and for the fact that I hate renting equipment from the cable company, I would never use one of their modems. I purchased my own modem/WiFi router - a Netgear C7100V - because I also have Comcast phone service. If you absolutely do not need/use WiFi, there are modem only units available which provide the single Ethernet connection to your computer.

If you do not need telephone service from Comcast, a 16x4 DOCSIS 3 modem only such as the TP-Link TC-7620 will get you 370 Mbps internet speed with Comcast and cost about $50. It does not have any router, including WiFi, will allow you to only connect 1 computer (unless you connect a separate router to it), and would pay for itself within 6 months of not paying rent on one from Comcast.

NavyLCDR said:

Since your computer uses Ethernet, you may not realize that what Comcast gave you is a combination modem and WiFi internet router. The 2.4 ghz and 5 ghz lights are the WiFi channels.

The question is what did you set up for security for the WiFi channels? Did you give the WiFi network a name (SSID) and did you set a password for it? Anybody with a WiFi device within range can see your network (in most setups) and if a password is not set, they can connect to your internal network. Both 2.4 ghz and 5 ghz channels are active - it's a dual band WiFi router/modem combination.

Thanks for the info. I did set up a name and password for the network. I live in a private house, how close would someone have to be to connect to my WIFI if I didn't have a password?

How close are your neighbors? My nearest neighbor is across the street, about 25 yards away and I can pick up their WiFi signal fairly strongly in my house.

I have a house on either side of me, around 15 to 20 feet away. How do you recognize the signal is from them? I don't know much about these things. I recently got my first smartphone and set it up with my Xfinity WIFI, I used the WIFI to download an update on the phone. I was surprised when I was looking around on the phone again, that there were around ten more WIFI names in my settings.

Bigfoot said:

I was surprised when I was looking around on the phone again, that there were around ten more WIFI names in my settings.

In all probability, wherever those WiFi names are coming from on your phone can also see your WiFi signal.

The only way to tell who is connected to your WiFi is to go to your router settings and look at connected devices:

Interesting NavyLCDR, thank you!

About the OP, I did an online chat with a Comcast agent and he told me that my modem was fine, the both lights should flash because it's constantly transmitting data from the internet. So, at least I got an answer and won't worry about it anymore.

Bigfoot said:

About the OP, I did an online chat with a Comcast agent and he told me that my modem was fine, the both lights should flash because it's constantly transmitting data from the internet. So, at least I got an answer and won't worry about it anymore.

It's up to you.... the two biggest questions, though, are:

1. Are you sure both the 2.4 ghz and 5 ghz WiFi channels are password protected? and
2. You don't care about your guest WiFi signal "exfinity WiFi" that anyone with a Comcast account can access?