ARRIS/SURFboard → Re: SB6120 continuously blinking activity light

Looking at the ARP contents I am confused. The format in the info section is:

who has IP tell IP

I have looked up half a dozen of the IP addresses and they are all Comcast. I am guessing they are servers looking for modems, but do not understand why they would be doing that. The modem should announce itself when it is powered on rather than the network constantly hunting for someone to talk to.

Example IP pairs: 76.149.183.4 76.149.180.1
22.16.200.92 22.16.200.1

Could it be other customer(s) on your WAN subnet?

After all, if you query your own public IP it'll come back as "Comcast" right?

The aggravation continues... I am in North Florida near Tallahassee, a long way from Seattle. ARP is beyond my expertise level, but if "servers are looking for modems", maybe this could be to apply modem firmware updates? - just an idea. Anyway, I am sure it is a Comcast issue, but they deny it. It doesn't make sense that my network works fine for months and then suddenly something changes one bright Monday morning with no explanation. The phone support I have been able to reach has been completely useless. The last person couldn't get me off the phone fast enough because they had no idea what to do and didn't even believe their own instructions. I am curious - are you able to run a speed test to "http://speedtest.comcast.net"? If so, do you get reasonable results? I don't - I get about 3mbps for download now where before I got between 12-16. Thanks...

More info. I don't know if this will help any, but I was able to save my modem's log info. I noticed the modem had only been up/connected for 30 minutes or so when I looked at this info this morning - that was weird to me. It should stay connected most all of the time. I don't know what this info means exactly, but I did notice that the modem's firmware version is newer than what has been tested/approved by Comcast. Hope this helps in some way...

I thought about someone trying to look at other peoples modems. It is strange however that the tell IP changes a lot. If someone were looking around, I would expect to see a single IP as the tell, though there is no reason it could not change.

I used speedtest to my closest server and used the Comcast speedtest to the closest offered point. They were both about the same speed and both were what they should be. I really would not expect them to have changed because of the ARPs. I have not seen any performance issues after the start of the ARPs.

Try Wiresnake and connect your PC directly to your modem. Be sure you have your firewall running in the PC. That will confirm you have what I have.

Ok, I'll have to take my network down and go to the simple modem-PC config a little later in the week. Comcast is coming Friday afternoon. I am going to have the simple config in place before they get here so as to eliminate all the blaming of my cables, my router, my splitter, etc., etc.. Although, if things go as I expect, they will probably blame the SB6120 I bought off Amazon instead of leasing something through them. We'll see. If anything valuable comes out of that visit, I'll make sure I forward it your way. I am wondering if the link light behavior can be related somehow to the connection errors that have started showing up in my modem log...

I looked at your log. I am not seeing that sort of stuff with any regularity.

Would it not be nifty if they could get the clock/calendar to match real time. It would make it a whole lot more useful to correlate an occurrence with other events.

I was trying to collect a list from people in the Comcast user forum that told me when the link light started blinking and their approximate location. The thread was locked because I should not have multiple postings. But that would be useful information to bring to Comcast.

After I told them my signal strength was within tolerance and showed them my log messages, Motorola support instructed me to reset the modem to factory defaults and see if it corrects the light issue. I don't know why it would change in the first place and have to be corrected with this sort of drastic step. I also can't afford to lose my connectivity for the next day or so if I reset the modem as requested. Have you tried this to see if it helps?

Yes I did reset the modem. I selected reset to factory defaults and rebooted. Worked fine but did not change the ARPs from being passed through to the LAN port. The light continues to blink.

Interesting points, but, I want it fixed. It is my desire to have it work as it was when I bought it. That operation may not be changed without my agreement. I use that light for my own purposes. For my personal use, I deem it a problem. I am not arguing about how the net works. Nor do I believe how the internet works play a direct role in whatever changed the behavior of my modem.

Is there some particular reason you wish to argue whether I should have it corrected or not? Does returning it to the initial, and sort of by definition for this modem , the correct operation, cause someone harm?

If you want to use your modem on their network it must be manged by them which includes firmware and configs, every DOCSIS cable modem is like that every DOCSIS providers is like that, if you dont like that use one of theirs or dont subscribe to them, is really your only two options.

As for the APR If you block APR you would have no net access, its that simple, APR is used to find the MAC address associated with an IP address in the same subnet, If you blocked it your router would not know how to contact the gateway as well as anyone else in your subnet.

As for the light blinking

»shaw modem "activity" light going nuts???
»Shaw FAQ's »My modem is flashing/not flashing, what does this mean?

I believe it can be controlled by changes to the config file or in the firmware but I highly doubt you get this changed yourself

To add:The factory defaults are overwritten by the config once it logs on to the network which put it in the same sate it was already in, so basically it dose nothing at least in the way your trying to use it.

What Napsterbater said....The moment you hook up your modem to the Comcast network, you are implicitly giving them all the necessary rights to control your device as they see fit. This is on par with having a car without a license. You have your car but you can't drive it anywhere until you are given a driver's license. Once you get the license you abide by all the rules and regulations written by someone else. Eg. The speed limit.

The behavior can be the result of having that modem upgraded to a new version of Motorola software, or changes to the configuration file that is downloaded by the cable modem from Comcast.

Even if you figure out what caused the modem to change it's behavior there's an extremely small chance you'll revert it to old behavior.

I believe Moto "fixed" the issue for many other customers in returning the PC/Activity light to it's classic blinking that the previous Surfboard modems have had for years. I'm sure there where a few complaints to Moto that the 6120 wasn't blinking like the previous generations of Moto modems.

I doubt Moto would change the behavior of the light back to what most Moto customers consider non-standard behavior for Moto modem status lights.

Basically the new light pattern didn't "feel" right to the techs used to working on Moto modems...