Running a long console line

[David Ruess]

I am trying to run a long console line with switches and fiber/ethernet for connectivity.

I have a USB -> Female console connection attached to my computer. From that I have an ethernet cable (straight thru) run behind my desk to plug into console ports to configure switches at my desk. This works! The problem is I have a blank switch installed that cant be connected to the network until fully configured and its already mounted not to be removed. It is installed buildings away. What I have done is I have connected the Console/ethernet connection on my computer to a port on the wall by my desk, which I traced to the COMMS closet. From there I patched that into a blank switch I just put in there to convert the ethernet patch to fiber. From there I connected fiber to the switch and into the fiber patch panel and patched it all the way through to the building with the switch I need to configure. The other side connects the fiber to another blank switch to convert back to ethernet which is plugged into the console port of the device I need to configure.

A few things to note: Its MM fiber switch to switch and there is link lights between switches. THis is pretty much all I can work with. I cannot install any software on my machine or purchase/install any "remote mgmt" console solutions. I know they exist.

Also important when I launch putty I can see characters running across the screen. Its just jibberish but it looks like basic connectivity. Ive tried adjusting settings/BAUD rate but haven't tried everything and am open to suggestions.

TLDR: I need a super long console cable to console into a switch in another building patched to my desk through fiber and ethernet.

[MichaelMcCoy]

Hello David, 

Excuse me if this is in poor taste, as I don't post a lot here, I'm assuming you create your config, and just load it onto the switch via a laptop?  

I tried to lookup, but could not find if the console connection on a Cisco device is MDIX capable, so you may try tinkering with a crossover vs a straight through on one side of the links.

[David Ruess]

I usually just console in from my laptop to the switch on my desk and configure it from copying a notepad file...essentially I'm trying to do the same thing...but the switch is a lot farther away. I was thinking about different cables (crossover/rollover) but didnt have any to test at the moment. I figured it works with a straight thru from my desk since Its a USB to female connector connected to my laptop and I just plug the straight thru cable in.

[Martin L]

not sure but I think your Ethernet patch to fiber converter thing may cause issues. We have done config with following setup : regular CAT5 used with Console port to Ethernet converter (3 inch orange converter used at your end connecting Console witch port to Console server).  This works as long as you are not more then 100 meters away.

you can temp configure your switch before pushing final config.  I would move my laptop and console cable near that mounted switch and push a temporary config that enables telnet via any unused IP and vlan on the main network. This is only temporary setup and  config.  Once you got telnet connection, you can move back to your desk and push final config via telnet.  Make sure you got Fiber connection from other switch/router via regular data vlan before disconnecting and disabling your temp telnet one.

Regards, ML
**Please Rate All Helpful Responses **

[David Ruess]

Thats whay I usually do when the switches are by my desk. But since this device is remote and no config on it I was trying to extend my console cable through fiber/ethernet patches and switches. The device cant connect to the network until its fully configured. We configure most other devices with a base config and deploy them and finish the configuration while its remote. This is just a special case. I need to be at my desk for this, otherwise I would go to the next building and console in.

[Richard Burts · Accepted solution]

I believe that the fundamental problem here is that while you may be successful connecting from your desk to device console port using Ethernet cable, what you are sending are not Ethernet frames. When you connect your cable to a switch and connect that switch to another switch etc the switches are expecting to forward Ethernet frames. But the console traffic is not Ethernet frames.

[David Ruess]

This is actually very insightful as I handn't though about it at that layer. I don't think I made it past layer 1. I had connectivity in terms of physical connection but no link lights (which I kinda expected because it wasn't actually "traffic") but I absolutely overlooked that part of the problem and didn't put 2 and 2 together.

P.S if anyone else sees this I also tried with crossover and rollover cables in addition to the straight through from previous comments. (Did not work)

Thank you. That was super helpful.

[Richard Burts]

You are welcome. I am glad that my explanation was helpful. I do not know how important the configuration of this switch is and how much effort it would be worth. But an alternative that you might consider would be to deploy a terminal server (it is possible to set up some Cisco routers to function as terminal servers or there are terminal servers available on the martket). The terminal server could be deployed very close to the new switch and connect via console cable to the new switch. The terminal server could be connected on your network, so that from your desk you could connect to the terminal server (telnet or SSH) and then make the connection from the terminal server to the new switch. There would be expense for hardware and would require time and effort on someone's part. But it would allow you console access to the new switch from your desk.