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Forum Discussion
CM1150V Not allowing network router to connect to Internet.
Today I bought a Netgear CM1150V Xfinity modem. (2nd of April 2020) Setup was easy. The firmware is the most up to date for today. The problem is the modem is blocking my routers from conecting to the internet. I have a Linksys EA8300, Cisco RV345, and Cisco E3000. Initally I hooked up the EA8300 wifi router and was unable to get internet to it. Then I hooked up the RV345 and had no internet problems other then no wifi. It worked great. I then hooked the EA8300 to the RV345 router and had wifi and internet on the EA8300 and RV345. It worked great for about 30 minutes. Then no internet to the EA8300 or the RV345. Then I hooked up the E3000 to the modem and again it worked great for about an hour then no internet. This whole time I had internet at the modem with no problems. I disconected the CM1150V and hooked up my old modem. I had internet on all my routers again. Then I hooked the CM1150V back up and did a reset to factory setings. I had the same problem I had to start with. I am able to use the RV345 again without any problems, but as soon as I hook a wifi router to it both get the internet blocked.
After contacting Comcast Xfinity they said, "there are no problems with my modem. It must be a problem with my router. And, since I own my modem they can't help me."
If it was a problem with my routers why do they work with my old modem. I checked for compatability issues before buying the modem and all these routers should work with no problems. I suspect Comcast Xfinity is using the firmware to detect and block wifi routers. Any ideas to fix this?
If I can't get it to work, sorry Netgear, but you can have your modem back. I will stick with my slow old one. When Comcast Xfinity has that much control over my network I don't want your product.
14 Replies
SOunds like the CM modem maybe faulty. I would try another CM modem. Users can connect any external router to the modem and should get internet access and not be blocked after a period of time.
You might try resetting the CM modem and have the ISP send down there configuration file again and see if this clears the problem.
Have the ISP check the signal and line quality UP to the modem.
Be sure there are not coax cable line splitters in the between the modem and ISP service box.
Be sure your using good quality RG6 coax cable up to the modem.IF this stil fails, Try another CM modem. Possible the one you have is just faulty.
FURRYe38,
Right now I have 3 Cisco RV345 routers running in a chain. Everthing works, but as soon as I hook up any of my wifi routers to the chain it will drop internet to all of the routers between the modem and whatever Cisco RV345 I plug into. The RV345 does not have wifi and works as long as I do not hook up a wifi router to it. The first RV345 has network CCTV cameras and a CF-WA900 comfast router with six 100w linear ampliphires running to three 2.4g 60db omni antennas and three 5.8g 60db omni antennas on a 25 foot communication tower. The second RV345 has 6 computers hardlined and a Linksys EA8300 wifi router hooked to it. The EA8300 is hooked up wifi to four smart TV's. The 3rd RV345 hardlines two servers and a Cisco E3000. The E3000 is hooked up wifi to 5 tablets and an Ipad. My ISP (Comcast Xfinity) has re-pushed the firmware to the modem four times. I still had the same outcome. I thought about it maybe being the modem and picked up another one from Best Buy today 3rd of April 2020. Still having the same outcome after two more firmware push tries. I think it is the ISP firmware and not the modem. I think it is their way of trying to get me to rent their wifi modem or pay for wifi on their system and get more money out of me. FYI: That will never happen. I will switch to T Mobile and run a hotspot router before that ever happens.
I had a very similar problem. I ultimately solved it by having my entire system connected as I wanted it (i.e., the ethernet cable connected between the cable modem and the wifi router), with everything powered on, then called Comcast/Xfinity on my cell phone. I verbally spoke the option "no internet connection" when the robot asked me to describe my problem at which point the robot reset my entire system remotely. It sent me a text message saying it was starting the reset and then hung up on me. Ten minutes later I got a message that my system had been reset. At that point, I was able to go through Netgear's protocol of setting up my new Wifi router, which included updating the Wifi router's firmware. It was however, obvious as soon as Xfinity had reset my system that things were going to work.
Further comments
1. I spent many hours trying to troubleshoot this before hitting upon the relatively quick solution above.
2. I called Comcast/Xfinity twice before my successful call. For these first two calls I had said I need to "Activate my system". Each time I was connected to a human. The first human got my information then tried to transfer me to an activating agent at which point my call was dropped by Comcast. The second agent insisted that I did not need to activate, said she had been working for Comcast for 20 years, that she could not possibly be wrong, and hung up on me. So the trick was getting a robot, not a human.
3. Comcast documentation and human advice seem to convey that once the cable modem is working, it doesn't matter what is hooked up downstream. This is demonstrably false. I was able to hook up only one device at a time (my old wifi router, or my computer directly, or my new wifi router, or another computer). In order to swap these out, I needed to use my cell phone to call Comcast and have the robot reset my entire system. In the case of directly connecting a computer, there was a way to do this directly form the computer browser, but I couldn't figure out how to do this directly with a wifi router.
4. Before hitting on the correct solution, I tried a number of tricks, like setting a static IP to the router equivalent to the IP that Comcast had previously assigned my desktop computer. But I was not successful.
5. I was getting close to giving up and surrendering and buying an Xfinity Gateway. Xfinity definitely has a conflict of interest in providing advice or making it easy to connect your own gear.
6. It wasn't strictly true that I had "no internet connection" because I did have a connection through my desktop computer. I just couldn't figure out how to change that connection to the wifi router.
7. I was not able to update the Netgear Nighthawk router's firmware until after I had the system reset by Comcast.
8. Merely turning off the power to the cable modem does not work. It has to be reset remotely by Comcast.
9. After posting my original message in another thread, someone suggested a Factory Reset of my cable modem (using the button on the modem) would work equivalently to having Comcast reset my modem remotely. I did not try this, but I suspect it would not have worked for me, as there seems to be a phenomenon of Comcast knowing what I have plugged in downstream. Not sure how, maybe through the MAC address. So you might try the factory reset button. But it is probably just as easy to have Comcast do it remotely unless you don't have a way of phoning them with a cell phone or other phone.Have the ISP check the signal and line quality UP to the modem.
Be sure there are no coax cable line splitters in the between the modem and ISP service box.
Be sure your using good quality RG6 coax cable up to the modem.
Be sure to power OFF the modem for 1 minute them back ON.You can factory reset the CM modem your self as well. There is a reset button on the modem. Press and hold it for 15 seconds then release.
My brother is one of them high IQ computer nerds with no education. After downloading the firmware off the modem. He found a line where Comcast was in fact blocking use of an external wireless router. They want you to rent their equipment and this is how they do it. I had one of two choices. I could rewrite the line in the firmware and have to rewrite it every time Comcast did a firmware update or set my router up as an access point so eveything on that router was pulling an IP from the modem. I doing this I ended up buying another router just to use as an AP. Once I setup the AP I was able to trick the system and hook up my other 4 routers as normal routers and not in access point mode.
It's funny people ask me all the time, "why do you want to sit behind 4 routers."
Here's why: I use them as part of a custom firewall. I have an old pentium 3 sony viao desktop hooked to all 4 routers. It does a few different things, but its main peruses are to scan my network for trojan programs, nesting programs, and foreign mac addresses that are not in a set list. When it finds a foreign mac address it drops a nesting program with a trojan virus onto the device with the foreign mac address. The nesting program does 4 things. 1. It replicates it's self and sends out copies to every device on the foreign devices network including the modem and routers. 2. It roots its self into the firmware and bios of every device on the network. 3. Its locks down all the data on all the hard drives in the network. 4. It forces an over clock of the frontside bus to 8.3ghz on all computers on the network.
I have to love my little brother for this program. It runs on MSdos, but it won't run in windows. It is a patented and copie written stand alone operating system that has never been distributed.
