Cisco 2621 router console problem using USB serial

[richard pititto]

hello

iv'e been having a problem with my Cisco 2621 router because i've been using putty to connect to the console port and i havn't been getting any text just a blinking box, ive also tried hyper terminal and another program, ive tried everything and was wondering if there is anything i could do about it, i don't use a serial port but a usb extention with serial connnection and was thinking that is the problem because of compatibility.  This problem started out of no where and the router was working and than it was not getting anything from the console, the router still runs with a blinking light, maybe its broken.  If anyone has any feedback about this problem that would be great, ive searched the internet for a solution and could not find much.

thank you

richard

[Peter Paluch]

Richard,

I do not believe this is a matter of compatibility. A Cisco device does not care whether your console connection is a "native" COM port (RS-232) or whether it is over a USB converter. If your USB-to-serial converter works on a different Cisco device then the 2621 should be working as well.

Are you actually able to log into the router remotely, perhaps via Telnet or SSH? If so, you should verify the configuration of the console port - the line con 0 section. It is possible that for some reason, the speed of the serial port has been changed from the default of 9600 bps, or that the port was configured to not start a command prompt.

If you are able to restart the router, are there any messages being printed out on the console as your router is powered on?

In any case, the first remedy with console problems is always testing out all supported console speeds, just in case the console speed setting on the router has been changed. You should try setting your USB converter to 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200 bps, one at a time, then hitting the Enter key several times to see if the router responds in a readable way, and if not, proceeding to the next speed in sequence.

Also, you should test whether the router at least produces any readable console messages by having your USB converter connected to the console port and then disconnecting and after a couple of seconds, reconnecting a live network connection (a serial link or an Ethernet cable - of course if you can afford breaking the connectivity for a couple of seconds). Making interfaces go down and up should produce a logging message being displayed on a console. If these messages appear but the router does not react to you hitting the Enter key, it is possible that the command prompt has been disabled on the console (a rather common mistake when trying to configure no exec-timeout and configuring no exec instead).

Also, this router has an AUX port. If you have configured it properly, it will allow you to access the device. Have you tried connecting your USB converter to the AUX?

Best regards,
Peter

[richard pititto]

thanks for the feedback peter

i think your right and i will try to reset the router when i get to also I've been looking into another solution if the console is turned off, maybe i could connect to a "cisco access server", maybe you have some experience with this equipment because i don't but they look interesting and might help, get back to me if you know anything

thank you

richard

[Peter Paluch]

Hi Richard,

With regards to access servers, or terminal servers, these are devices that allow multiple users to remotely access console ports of attached devices, such as routers or switches, over a network. The basic idea is that a terminal server has an IP address, and by using Telnet or SSH into this IP address and a specific TCP port, a user can access the console on a specific device attached to this terminal server. Each console link on a terminal server has a distinct TCP port, so a terminal with 16 console links has 16 TCP ports, say, 3001 through 3016, each of them representing a single console link.

I am afraid I do not entirely understand how you intend to use these servers. They are certainly not intended as replacements for the USB-to-serial converters, and they will not save you if your console port is either fried or so misconfigured that it is unable to communicate.

Best regards,
Peter

[Reza Sharifi]

Hi,

In addition to all the great suggestions and questions by Peter, is the USB port compatible with your PC?  Another word, when you plug in the console port to your PC, does the USB port pick a com port?

Note: Not all USB drivers work will windows. If the driver for USB converter does not get installed after you plug it in the first time, than that USB is not compatible with windows. Sometimes downloading and installing a newer driver will fix that.

HTH

[m.rana.ku]

Hi,
In the following video step by step process has been shown how to Connect Cisco Router or Switch using PuTTY and Console Cable as well as how to Change Text Color, Font Size, Background color permanently on PuTTY.

https://www.youtube.com/channel/UCmZZ2BNGXQH1HPS3uIVnr7A?sub_confirmation=1

https://youtu.be/WQeAe8_vbLI

First Download and install PuTTY (emulator terminal software) from https://www.putty.org/

Step 1: Attach the DV9 Female end of Console cable with the DV9 Male end of the USB to DV9 Serial Converter and then connect the RJ54 connector end of the Console cable to the Cisco router or Switch.
First check the COM port number

Step 2: Check the COM Port number:
=> Go Device Manager->Port (COM & LPT)-> check USB Serial Port (COM port)

Step 3: Open Putty
-> Select Connection Type to "Serial"
-> in Serial Line change the COM port number exactly which we checked in step 2.
-> click open and a black window will appear and press Enter finally it will access the Cisco Device.
-> Type "enable" to go to privilege mode.