CRC Errors indicative of bad switch?

[Stirfry2112]

I am no where near being a network expert, so please be gentle. For a few months now, we have had a spotty network, both hard wired and wireless. Works fine until it doesn't, and when it doesn't, it is painfully slow. I have a GS308E Netgear gig switch that has some reporting. I noticed we have some CRC Error Packets and I am wondering if this proves anything for my network issues. See snapshot below:

So, now that I have documented CRC errors on multiple ports, does that help with diagnosis? Does this mean the switch is bad? Or is this a fiber internet issue? I was thinking bad cable, but nearly all the ports have errors, which confuses me. Here is my network tree:

Fiber modem (500/500) - This is only a modem, not a router. Fiber port, ethernet port, and telephone port
|
Firewalla Purple (DHCP Host)
|
Netgear GS308E 8 port switch
| | | | | |
input Mesh AP network. Unmanaged 8 port switch . Unmanaged 8 port switch. NAS Security Cams.


There are more devices, but just wanted to show the top section I am working on. All cabled with CAT6 shielded cable for the most part. Any help is greatly appreciated. I am attaching some setting screenshots from the GS308E if that maybe helps.

 

[bogdanw]

Have you tried Cable Tester? I see it's an option in the first image.

 

[mcnallym]

If multiple ports then could be switch or could be unlucky

General troubleshooting guide

Are CRC errors incrementing?

• Yes: Move the cable to a different switch port.

Do the CRC errors move to a different switch port (using the same cabling and end device)?

• No: If the CRC errors are no longer present, the issue could be with the switch port. To check, connect a different device and Ethernet cable to the original port. If CRC errors continue to increment, then the issue is most likely with the switch port.
  End troubleshooting steps here.
• Yes: If the issue follows the move to a new switch port, then the issue could be the cabling.

Do CRC errors still increment after changing the cable?

• No: the CRC errors were caused by faulty cabling.
  End troubleshooting steps here.
• Yes: check to make sure speed/duplex match on the switch and end device.

Does the speed/duplex match?

• No: Change the speed/duplex so that they match. If the issue is no longer present, the issue is with the client device.
• Yes: Change out the end device. If the issue is no longer present, the issue is with the client device.

Can see you have the latest firmware

Doesn't seem to be a way to determine Duplex Status on the Switch but quite often that is the issue. Going to be trickier if the other device is an unmanaged switch as no way to find out what the switch thinks its speed and duplex are.

Not a fan of Smart Switches and even less of unmanaged as cannot see really what happening with them which makes this trickier.