Netgear CM1100 Modem will connect to mesh wi-fi, but not a router or computer.

[tap123]

My ISP was recently purchased by Breezeline (was WOW).  Now my modem will not provide a signal to any wired devices connected to it.  It is on and providing an internet connection (as evidenced by its connection to my eero mesh).  The wi-fi mesh works in either port.  When I try to connect a router, or computer directly the port light turns orange and it will not provide a connection.  I have tried multiple computers & routers, and switched cables multiple times.  

Tried the online support (useless - had already done all of that) hoping they would connect me with someone who knew something other than the online troubleshooting guides.  I suspect it is something the ISP is doing for security but there is nothing online about having to use their routers.

Modem Netgear CM1100, Router Netgear R6400 - latest firmware, (also tried TP link router and older linksys router as well)

[FURRYe38 · Accepted solution]

Be sure that the R6400 router is the only device connected to the WAN #1 port on the modem. The other WAN port can not be used.

Power OFF the CM modem and R series router for 30 seconds then back ON with the CM modem first, then the R series router. 

Connect ALL other wired and wireless devices to the R series router. 

If you have a Wi-Fi MESH system, you might put this in place with the R series router and use the MESH system instead of the R series router. 

Be sure your using good quality LAN cable, CAT6 is recommended. 

[FURRYe38 · Accepted solution]

Be sure that the R6400 router is the only device connected to the WAN #1 port on the modem. The other WAN port can not be used.

Power OFF the CM modem and R series router for 30 seconds then back ON with the CM modem first, then the R series router. 

Connect ALL other wired and wireless devices to the R series router. 

If you have a Wi-Fi MESH system, you might put this in place with the R series router and use the MESH system instead of the R series router. 

Be sure your using good quality LAN cable, CAT6 is recommended. 

[tap123]

Thank you will try this when I return home.  I'll leave feedback on how it works.

[tap123]

Thank you for the advice.  Finally got to it today. I rebooted using only the router plugged into the port.  Worked without a hitch.  R6400 handling the wired traffic with the wi-fi disabled.  Mesh net handling the wi-fi.

I have used both ports in the past so I was still under the assumption that I could.   Saved me a ton of frustration!

[FURRYe38]

Enjoy. 

[SharkWeek]

Power cycling WHILE ATTACHED to my 3rd part router really helped me with an issue I was having with my CM500-100NAS as well.

Thank you!