Is there a way to determine LAN/Ethernet/Wifi failure?

Your power levels are out of spec and you have errors in the logs. You might need to have the ISP check the line. 

@plemans can you point which power levels are out of spec? I can cross check again on those. 

I am having a weird issue that my LAN/Ethernet is giving internet speed but its has some glitch every now and thn, How can i debug that specifically for LAN?

Your downstream is a bit high and the upstream is a bit low. I’d work on getting those fixed first as they can cause errors and drops. Once that’s in spec, then you can worry about debugging lan.

@plemans Thanks for your replies. 

I have fixed the power level by chasing ISP (Xfinity) having tough time with them explaining it and fixing the power levels.

LAN Freezing/glitching Issue is still present.

Couple more steps/troubleshooting done where 

1. Changed Ethernet port to cat 6
2. Did test on all 4 ports 
3. Reverse ethernet lan cable from A→B to B->A
4. Factory reset modem (Help from Arris support)

LAN Freezing/glitching Issue is still present. Request someone to please guide asap.

PFB both upstream and downstream levels now which are within range as per docs. 

Please let me know what next i can do ? This is really frustrating that this is brand new and i am having issues with LAN/Ethernet which is very much needed for my entertainment purposes.

I’d keep in contact with support. Your levels do look better from the channels you posted on here. 

@plemans Support were not able to figure out why that is happening and i already have case raised and they said they have raised TIER2 support for more troubleshooting and someone would call within 24 hours. I havent got any calls yet. 

Very frustrating with customer support and level of issues this device is having.

Hope somebody from Arris support sees this message and take it on highest escalation level to resolve the issue once for all.

@SURFboard_Moderator @admin please guide/help.