TR Forums

Good morning,
I urgently need to be able to access switch One ENTERASYS 7C111 N1, but the com port there is no answer. I tried with a cable Cisco and Extreme Also an adapter without success. The connection parameters that I have used are the Following:

9600
no parity
8 data bits
1 stop bit
flow control XON / XOFF

it is possible that the com port is disabled? The RS232 cable to connect must be of a standard cable? The connection paraetri are fair?

There is no universal standard pinout for RJ45 console serial ports. The Cisco cable did not work because it has a different pinout. You will probably need to get a proper Enterasys console cable (one that is specifically designed to be used with Enterasys switches), or make an adapter yourself. Extreme Networks provides specs for the Enterasys console cable on their web site: https://gtacknowledge.extremenetworks.c ... le-adapter

If you decide to make your own adapter, you can use a pair of DB9 connectors (one male, one female), some bits of wire, and a soldering iron, to swap the signals around at the COM port end; or (if you have an RJ45 crimping tool) you can make a custom RJ45 cable that swaps the conductors around after the fact to get the signals on the correct RJ45 pins. I encountered a similar situation a couple of years ago (not an Enterasys switch, but another device with an RJ45 console port that didn't match the Cisco pinout). I used the second approach (made a custom RJ45 cable adapter), then used an inline coupler to daisy-chain it to a standard Cisco console cable.

Edit: If you decide to adapt a Cisco cable like I did, you will also need to know the Cisco pinout: https://www.cisco.com/c/en/us/td/docs/w ... 124h_e.pdf

I see that the Enterasys uses DSR/DTR (whereas the Cisco cable does not). This may cause problems with adapting a Cisco cable like I did, since Cisco does not use those signals. Simply looping DSR back into DTR at the Enterasys end may be sufficient to get it going.

Dear, I'll try tomorrow morning.

It may also be 115200 rather than 9600. Most stuff defaults to 9600 but then gets reconfigured to 115200 to get reasonable speed.

Well, if you can't hook up at 9600/N/8/1 you'll have to find the manuals, 'cause some developer was working overtime to be weird for weird's sake.

Vernor Vinge's "Zones of Thought" sci-fi series envisions a galactic USENET (yes, it's still out there). While he never states it, I guarantee it runs on 9600/N/8/1.

Captain Ned, you were absolutely right: it was the cable. I proceeded to crearmene one by following the instructions that you suggested and it worked. Thanks very kind.