Friday, May 13, 2016

Cisco Console in a Bind: Make your own console cable

Well, not technically a Cisco device but one that uses the same pin layout as a Cisco device. A few days ago I had a Ubiquiti Edgerouter Lite go bad, and had to poke around with it using its console port. Problem was I didn't have any Cisco console cables laying around. So I ended up making my own, using a DB-9 serial cable and an RJ-45 cable.

I was looking up some guides online on how to make the cable, and had to try two or three different pinouts to find one that worked. The one that worked, from left to right conductors upwards was; purple, green, brown, black, red, orange, and finally blue. Yellow was left out.
Final pinout: Purple, green, brown, black, red, orange, and blue

Once I got that finalized, I had to set the baud rate to 115200 in Putty to get it to display a console output, which went as follows:
Looking for valid bootloader image....Jumping to start of image at address 0xbfc80000

U-Boot 1.1.1 (UBNT Build ID: 4493936-g009d77b) (Build time: Sep 20 2012 - 15:48:51)
BIST check passed.UBNT_E100 r1:2, r2:14, serial #: DC9FDB806C3DCore clock: 500 MHz, DDR clock: 266 MHz (532 Mhz data rate)DRAM:  512 MBClearing DRAM....... doneFlash:  4 MBNet:   octeth0, octeth1, octeth2
USB:   (port 0) scanning bus for devices...      USB device not responding, giving up (status=0)1 USB Devices found       scanning bus for storage devices...No device found. Not initialized?                                             0** Can't read from device 0 **
It ended up being a bad internal USB stick, which I replaced with a Kingston SE9 8GB stick, and then used one of these disk images to get the ER-Lite working again.

No comments:

Post a Comment