[SOLVED] Linksys MR7350 requires cable modem to be factory reset after every power outage

[IceBergTYS]

I'm giving this a shot since the Linksys forum was decommissioned earlier this year. I recently upgraded from the Linksys WRT1900AC to the Wifi 6 capable Linksys MR7350. Everything functions great on it except whenever there is a power outage. Once power is restored, my cable modem (Arris SB8200) will subsequently come back online, but the router will seek connectivity with a flashing blue light but eventually goes red. I can't simply powercycle the router to get it to connect again. The only way I can get the MR7350 to connect again is to factory reset the SB8200. I never had to do this when the older Wifi 5 WRT1900AC was connected, which has me scratching my head as to what could be the issue here. IP address is dyamically assigned. Any ideas on what may be causing this and are there any recommended configuration changes I can make to my router or gateway?

 

[maikutech]

Did you try updating the routers firmware or contact the manufacturer for direct help with your complicated issues ?

 

[MJS WARLORD]

You say .... after every power outage .... my first priority would be to sort the power outage.
How often does this happen , is it just your home or all the area and are you using a surge protector.

I once had a power cut and when it came back on the lights were VERY bright for a few seconds before the power went of again , the excess voltage killed everything in my home apart from my pc set up because it had a surge protector. At first my insurance company said they were rejecting my claim for so many items but they later phoned to say they would pay out because lots of other people in my area were making similar claims so they knew my claim was genuine.

 

[Ralston18]

Have you contacted your ISP about the cable modem problem?

Connections (line diagram) being:

ISP === Coax ===> SB8200[LAN port] ----Ethernet cable ---> [Internet Port] MR7350[LAN Ports] --- Ethernet cable ---> to wired devices and
~~~~ wireless ~~~~> wireless devices.

Feel free to edit and correct my line diagram as necessary.

Arris SB8200 - This cable modem?

https://www.modemguides.com/wp-content/uploads/2021/02/SB8200-MANUAL.pdf

Reference Page 16, you may need assistance from your ISP.

When modem and router are all again working (after a SB8200 reset) are you able to access the cable modem admin screens per Chapter 5, Page 17 of the SB8200 User Manual using 192.168.100.1?

WR7350 Router:

https://downloads.linksys.com/support/assets/userguide/USER GUIDE - MR7300 Series - INTL_B00.pdf

Are you able to log into the router's admin screens via a browser and the router's default IP address ( most likely 192.168.1.1)?

No need to immediately change anything - just determine what you are able to administratively see and configure if some change is proven to be necessary.

 

[IceBergTYS]

I toggled some of the IPv6 configuration settings in the hope that my be the solution. At the very least I now know IPv6 is configured correctly. Awaiting the next power outage.

 

[bill001g]

Life will be much simpler with a very small UPS on the modem and the router. Even a small power blip means the cable modem will spend many minutes reconnecting.

I would see if the router is getting a IP address on the wan port from the modem.

Cables modems are pretty stupid. They will lock onto the very first mac address they see after power up. Maybe the router when it powers up is using 2 different mac addresses on the wan port and the modem has locked onto the first one.

Do you actually have to factory reset the modem. Try to leave the router powered on but unplug the cable. Then power cycle the modem. When it appears to be functional plug in the router.