Tuesday, May 12, 2020

Payment terminal keeps getting locked out of switches

We have this extremely weird issue, one of our customers have a payment terminal (People put in their cards and pay). Its a very simple unit, its connected via RJ11 (in the terminal) to RJ45 into a switch, all it needs to work is internet, simple enough. Its configured with static IP (DHCP does not make it establish a link)

The problem is that its randomly stops working, and the issue is that the link to the switch goes down, i can move the terminal to ANY other port and nothing happens, if i plug in a PC in the same port it works instantly. Its almost as if the MAC is banned or something, but the switch is a very old HP and have no such feature that i know of.

Ive tried turning off STP and all other features on one port but i cant get it to establish a link, there is nothing in the logs (Because the switch is so old) that says anything about the port. Now for something even more weird, we get a new payment terminal sent to us because the old one wont establish a link to the switch, connect the new one and it works instantly (Probably because it has a new MAC), all is good for about a month and it stops working again.

I take the payment terminal, plug it into our switch at the office and it works instantly, take it back to the customer and it wont establish a link. I then take a dumb non-manageble HP switch not connected to anything, plug the terminal in and it works, take the cable out and put it back in a few times, and then the ports stop working one after one until i get to the 4th port, this one seem to work all the time.

I take this new small switch, plug it into the big switch, then the terminal into the small switch and it works... Until now, now no ports work in the small switch with this terminal, i can plug a PC into any of the ports and it works instantly..

What on earth could this be?



No comments:

Post a Comment