I have a preplink balance one core. I have AT&T fiber and Xfinity. Everything has been working fine for the last year since I started using my own Xfinity modem. I have a surfboard S33. Well yesterday Comcast went down in my area and now my modem will not connect with the preplink. I rebooted both modem and router many times. I also verified that the modem has internet access by plugging into the Ethernet port. I did call Comcast and they had to provision the modem. Prior to that I had no internet. Any suggestions? I only have this problem with Comcast which is why I switched to my own modem. I’m ready to cancel it and roll the dice with one connection or try Starlink. Not a great shot at the north sky which is going to be a problem here in Florida.
Keep in mind that most DOCSIS modem authenticate with the first MAC address presented to the ethernet port. If you plug in your laptop and then plug in your Peplink, it will not work. You need to leave the Peplink plugged in during the reboot cycle of the modem.
Are you getting link lights on both the Peplink and the Surfboard when they’re connected?
Exactly my thoughts @ChristopherSpitler. See Surf SOHO MK3 never finishes connecting to cable modem if modem reboots, that summarizes what I went through a couple years back.
So base on the firmware hardware and firmware version you have you may still have the bug they had then, where some internal network MACs leaked out on the WAN occasionally. Even if you have a newer firmware, I noticed that occasionally some internal MAC addresses leak out on the WAN during the boot sequence. So my recommendation is first boot the router. And when it is fully booted, reboot the DOCSIS modem. With a recent firmware that doesn’t leak out MAC addresses from the LAN on the WAN, you should be fine if this is the issue you are experiencing.
Thanks guys. I did reboot the modem after I plugged my laptop into. I’ll try what you suggest with booting the Peplink and then the modem. Should I disconnect the ATT modem
Since you don’t know what is going on, I would to minimize variables, disconnect the ATT modem too. Then reboot the Peplink router, wait for it to be fully booted (it can take a few minutes based on the model, wait until the web admin is available and the CPU % settles down). After that, reboot your XFinity modem. Hopefully it connects fine (you should see it on the Peplink Dashboard). After that when everything is good, re-attach the ATT modem.
Once you have a working scenario, you can see if the ATT modem needs to be detached or not (probably not). In the end, all it takes is one rogue packet from the LAN to leak out to the XFinity WAN port for it to be the first MAC seen by the XFinity modem, and then the modem will ignore all others, including the Peplink router. In my experience with the latest firmwares, this only happens occasionaly during the Peplink router boot. Hope this helps.
Thanks. I’ll give that a try tomorrow am before everyone gets online. I have noticed that when the ATT modem reboots sometimes it gets a LAN address and I have to disable it and then enable it and then it will show its external ip address. Wondering if I should upgrade to the B-one. I’ve had no problems with one I have at a different location.
I actually unplugged the Xfinity wan connection rebooted the modem and waited until it was back online before I plugged it back into the wan port. That did the trick. I read that in peparn’s post from back in 2018. At least I know a repeatable procedure now.