topic Re: Trouble connecting to the C5G124-48P2 switch in ExtremeSwitching (Other)

Trouble connecting to the C5G124-48P2 switch

Laser-Eyes66 — Tue, 19 May 2026 02:06:59 GMT

I purchased this switch used and would like to reset it, but I can't even get the console to appear. I am using putty, and I have the correct port selected. I tried a regular and a null modem de-9 cable but have had no luck. If there is a jumper inside I can move or some other method to reset it I would appreciate any advice.

Re: Trouble connecting to the C5G124-48P2 switch

Bill_Handler — Tue, 19 May 2026 12:36:22 GMT

Laser,

There is no jumper inside that I know of. The null modem cable should work without issue - 9600 baud, 8-None-1 are the standard settings. If you have the cables connected when the switch boots, are you getting any input? Do you have another device you can test the null modem cable with? Do you have a serial port on your machine or are you using a USB to serial converter?

Thanks,

Bill

Re: Trouble connecting to the C5G124-48P2 switch

Laser-Eyes66 — Tue, 19 May 2026 20:21:40 GMT

Thanks for the response. I was certain I did everything right and even double-checked after your message, but I eventually found the issue: it was me.

To anyone who finds this post years from now with a blank terminal, make sure your computer's serial port is actually working. Mine worked fine the day before but suddenly quit. Since my laptop (a Dell 5424) has a built-in DE-9 port, I assumed it would never give me issues since there were no adapters involved.

If you suspect your port is bad, try a quick loopback test:

Connect pins 2 and 3 together to short RX (Receive) and TX (Transmit). This forces the port to receive exactly what you type.
Open PuTTY and type a few letters. If nothing appears on the screen, your serial port is the culprit.

In my case, going into the BIOS and reassigning the port to a different COM number completely fixed the issue. Or maybe it just needed a restart.

Re: Trouble connecting to the C5G124-48P2 switch

Brent_Addis — Tue, 19 May 2026 21:19:22 GMT

Glad you got it resolved, but holy wow that's a 16 year old switch. Entirely surprised it still works honestly, I've had a few of those over the years and they've all gone to meet their maker.