Question about 3Com 3C16985B /REF3COM SSII 24-PORT SWITCH (3C16985BREF)

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Link and activity lights on 3Com Switch ports without connection

I have this problem with three 3Com switches. There are link and activity lights on ports that have no cable connection on them. The lights remain on and blinking even when I remove the RJ45 plug. how can I repair the switch.

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Re: Link and activity lights on 3Com Switch ports without...

Do the ports work when the cables are connect?  I did some re-search and this seems to be an ongoing issue with 3com switches.  It should not effect the use of the switch

Posted on Oct 27, 2007

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2 Answers

3com Switch Intermittently Losing Connection.

this could be a problem with the second switch unit. what happens if you connect a pc to this cable, is that intermittent, if so, that is your problem. try fault finding with a LAN cable tester to see if there's any issue with the link cable.

Jul 16, 2013 | 3Com Baseline Switch 2024 24-Port...

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3Com Baseline Switch 2024 - Switch - 24 ports duplex light blink continusly

Is it hsappening with all the 24 ports or with some ports ?

Might be an indiacation towards the duplex mismatch.
are you getting CRC errors on the interfaces ?

Dec 05, 2010 | 3Com Baseline Switch 2024 - Switch - 24...

1 Answer

I have a 3com 4500 connected to 2 5500s (A & B), which are the the GWs for the 4500. I issued on the 4500: ip route-static 0 preference 60 (5500 A) ip route-static 0...

From your scenario what i guess is the two 5500's (A&B) are connected to each other also. Thats why the link between B&4500 is remaining down due to STP ( to avoid Network loop).
Please correct me if I am wrong.

What is the status of the link connecting 4500 to 5500 B when 500A is active and when 5500A is down .

If you are running STP i will suggest you to wait for 2 minutes after 5500A goes down and STP will be recalculated and the link connecting to 5500B will become active and then the route will also become active.

Best regards

Nov 02, 2010 | 3Com 4500 24-Port Ethernet Switch

1 Answer

My 3com 4200 28 ports is restarting by itself many

Base from the description of your problem its only showing that some of the port on of your Ethernet switch is already getting bad and this usually happen on switch like this and eventually all port will go bad and will lead to the replacement of the device. With this type of problem you can first try to adjust the speed of your network card to 10 half duplex and check if that will correct the connectivity problem and if it does its just a sign that sooner or later the device is already getting bad and since its only a switch there's no firmware that we can load to it or even a reset button to bring the device back to its default settings.

Jan 27, 2010 | 3Com 4200 24-Port Ethernet Switch

1 Answer

Uplinking Using Gig Copper

hello, use the plugin modules for the rj 45 connection port to uplink it.

Aug 04, 2009 | Networking Hubs & Switches

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How to check whether its working or not working?

If your PC LAN Card is active just connect the switch with Straight cable - & --you will see one yellow box in ritht side corner down to monitor screen...where the time appears.....also you can check in the Network Connections Folder. Or Right Click My Network Places> Properties> You will see local area Network....> Connected...then it is working if disconnected it's not working....Good Luck

Jul 29, 2009 | D-Link DES-1008D 8-Port Ethernet Switch...

1 Answer


First thanking to using d link switch

Tell me Your dns

and using pppoe ya proxy


Mar 11, 2009 | D-Link DES-1008D 8-Port Ethernet Switch...

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3Com 3c17304 port 25 up not connecting

Well I think the port is bad, I had one that did something similar to your problem. I got on the 3Com website and submitted and RMA request and they upgraded my with the newest model. But if yours is still in stock they will replace with the same type. That is what I would do. Hope this helps ya.

Feb 25, 2009 | 3Com SuperStack 3 4228G 24-Port Ethernet...

2 Answers

I cann't connect to my switch

The primary connection method for those switches would be serial connection. In the box there should have been a DB9 serial to RJ45 cable. Hyperterminal default settings would allow you to connect.

Jul 25, 2008 | 3Com 4500 24-Port Ethernet Switch

1 Answer

Enter the switch configuration

page 22 of the 3com user guide for your switch talks about how to use the console cable and how to connect to your pc, I included the link below for your manual, if you don't have it:

Jun 18, 2008 | 3Com Networking Hubs & Switches

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