[REQUEST] RJ 45 Serial cables. PINOUT?

[nlinecomputers]

I have Cisco console cables with RJ45 on the end of it and even the old never seen anymore DB9. But lots of devices have RJ45 ports that are not "Cisco"

I also have an old USB to DB9 Serial port. And I have adapters that have DB9 female on one end and RJ45 female on the other. So to plug that up I would need a patch cable. Will a regular ethernet patch cable work? (doubtful) or do I need to crimp my own cable? If so what are the pinouts on both ends?

I also have an RJ45 rollover adapter that supposedly allows a regular RJ45 serial cable to talk to Cisco because they use a rollover? So If I put this on my Cisco console cable I would have a double rollover and thus a clunky but working straight through?

 

[Sky-Knight]

It greatly depends on the Cisco device you're connecting to... have to look that up to figure out what it's console requirements are.

I have a pair of RS232 to RJ45 adapters I use for this stuff... but it won't work with Cisco gear that requires a rolled cable. Then I wind up crimping a rolled patch cable to do this.

 

[Markverhyden]

Those communications serial. So a roll over is basically a null modem cable, where transmit and receive are reversed. This was before they had circuitry was sufficiently developed to automatically do what needed to be done. This is why we used to have cross over rj45 cables between network devices but no longer need to.

Serial to serial? As mentioned above we're reversing the pinouts to allow communications. I've only ever have seen one device that could not use a straight through serial. A big APC unit from late 90's early 2k. Had another cable labeled APC which worked. Given it's age I guess it was a null modem wiring config.

 

[nlinecomputers]

The issue is that I only have a blue usb Cisco console cable, which has a built in rollover. But if I come to a Fortinet device that will not work. I also have an RJ45 rollover adapter, which is intended to attach to a straight through RJ45 serial, which I don’t have and can’t find in stock and perhaps don’t need? Because if I attach it to the Cisco Console I will have a double rollover making it straight through. Am I correct?

 

[Markverhyden]

Can't say about Forti products but a quick look around and they indicate it does use a roll over (null modem). So you would need another roll over/null modem adapter to convert it back to straight through if that was a necessary connection. But I've never had to use a straight through DB9-RJ45 cable. I do have a mess of various DB9, 25 male female gender bender etc, including a null modem adapter which will pretty much every possible scenario.

https://www.amazon.com/StarTech-com-RS232-Serial-Modem-Adapter/dp/B000DZH4V0

Connecting to the CLI – FortiOS 6.2

Connecting to the CLI You can access the CLI in three ways: Local console — Connect your computer directly to the console port of your FortiGate. Local access is required in some cases: If you are …

www.fortinetguru.com

 

[NETWizz]

A console cable is not a null modem cable but similar. A null modem cable is a cable for linking the serial interface of one Cisco router to another. For example a WIC-1T to a WIC-1T or similar interface card.

Does your console cable work on Cisco? I think there may be a problem with your USB to Serial adapter. If you are on a Windows machine, I very strongly suggest a recent "genuine" FTDI chipset cable. It is the one I use that the driver never bluescreens Windows and it is totally reliable every time.

At any rate, you need a DB9 to Rollover adapter for Cisco. I occasionally add a coupler and a LONG network cable if I want to extend a rollover cable.

Did you check the baud rate, data bits, stop bits, parity, and flow control in your terminal emulator?




I do think the pin-out is likely different though because this is Fortinet according to the Internet




Here is Cisco's

You would need to compare that against this to convert the Pinouts...

I do not have time to really figure it all out for you and would buy a Fortinet console cable personally.


Basically, if you see that 5 goes to blue-white blue, which is 5 up from the bottom except this is oriented upside-down, basically the one that goes to Green needs to go to red.

On 568-B that would be the Brown instead of Green, so you would need to move the Brown to Blue within the 568-B scheme to move Green to red.

cisco: 3 goes to 6 (yellow)... that is 6 from the top or White-Green/Green on 568-B, but on Fortinet 3 goes to solid-green 568-A

Hence you would move white-green/green to be green instead.




***

Basically, go through the list and make an adapter