Access the console using RJ45-to-USB adapter

[a.m]

Hello,

I was trying to connect to my switch using RJ45-to-USB adapter, like the one shown in the photo:

I failed to get access, and I got the following messages under Linux's dmesg :

[  183.932077] usb 1-1.2: new full-speed USB device number 7 using ehci-pci
[  184.012073] usb 1-1.2: device descriptor read/64, error -32
[  184.200070] usb 1-1.2: device descriptor read/64, error -32
[  184.596067] usb 1-1.2: new full-speed USB device number 8 using ehci-pci
[  184.676073] usb 1-1.2: device descriptor read/64, error -32
[  184.864072] usb 1-1.2: device descriptor read/64, error -32
[  185.052080] usb 1-1.2: new full-speed USB device number 9 using ehci-pci
[  185.468071] usb 1-1.2: device not accepting address 9, error -32
[  185.548074] usb 1-1.2: new full-speed USB device number 10 using ehci-pci
[  185.964068] usb 1-1.2: device not accepting address 10, error -32
[  185.964316] usb 1-1-port2: unable to enumerate USB device
[  253.160072] usb 1-1.2: new full-speed USB device number 11 using ehci-pci
[  253.240073] usb 1-1.2: device descriptor read/64, error -32
[  253.428076] usb 1-1.2: device descriptor read/64, error -32
[  253.616074] usb 1-1.2: new full-speed USB device number 12 using ehci-pci
[  253.696075] usb 1-1.2: device descriptor read/64, error -32
[  253.884043] usb 1-1.2: device descriptor read/64, error -32
[  254.072074] usb 1-1.2: new full-speed USB device number 13 using ehci-pci
[  254.488073] usb 1-1.2: device not accepting address 13, error -32
[  254.568080] usb 1-1.2: new full-speed USB device number 14 using ehci-pci
[  254.984072] usb 1-1.2: device not accepting address 14, error -32
[  254.984367] usb 1-1-port2: unable to enumerate USB device

Does any one have a idea about the problem ?

Kind regards;

[WIZARD1325]

Sorry I am unfamiliar with that device. The ones I purchased on Amazon work wonders. I know they have a build in chip (don't know what its use for) but I never had any issues

link below

https://www.amazon.com/gp/product/B01AFNBC3K/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

[a.m]

Your cable seems different, it contains 8 wires. My adapter includes only 4.
Does it mean that it isn't suitable for consoles ?

[WIZARD1325]

I could be totally wrong but I feel 90% certain. 4 wires are whats used for telephone communications and other things not Fast Ethernet/Networks

Just took a look at the photo and yes I am 100% certain you are using the wrong device my friend lol.

order one when the link i sent you.

 Those errors seems like there trying to communicate on but it can cause the wires on

5 6 7 8 are missing and your only have wires 123 4 connected

3, 6 are the RX ports

1 , 2 are the TX ports

TX=transmit

Rx= recieve

so the computer is receiving but it cant send because those wires are missing =0).

[a.m]

Thank for your reply.

The problem is that 1,2,3 and 6 are the connected pins in my adapter.

[nixpengu1n]

Hello,

There is nothing wrong with the device, Linux basically could not correctly recognize it. Please update device drivers on your Linux box if possible. 

[a.m]

Hello,

Thank you for your reply.

My Linux is up to date. Also, USB drives work perfectly.

Is there any way to check if the problem is Linux or the adapter ?

Regards;

[nixpengu1n]

Hello,

USB drives themselves are different thing. You are connecting a device through USB port. It could be that you may need USB to Console or USB to Ethernet drivers on you system to make it work.

First thing I would check - supplier web site of this device. May be there are some information how to make this thing work under Linux. 

[amikat · Accepted solution]

Hi,

I am sorry to say that in my view your adapter is intended for USB to 10/100 Ethernet usage (eg. USB modem to router LAN) ie. it is NOT suitable for the console port. While console ports use also RJ-45 type sockets the pin assignments are completely different. The "Console" is serial port NOT Ethernet.

Best regards,

Antonin

[a.m]

Hello

I found the answer, as @amikat said, The cable is not suitable for console. A USB-Serial converter (FT232R) is missing in the cable to work correctly.

I used this mapping before :

Regards;