# emulate serial via ethernet

## mattmill30

Hi,

We're trying to administrate some very old switches which use serial ports and can't seem to be able to find a crossed-over serial cable.

When it occured to me, couldn't we just emulate a serial connection via an ethernet, because for some weird reason, we have ethernet-serial, but not serial-serial.

Any ideas if this is possible, and perhaps where i might start?

TIA,

Matthew Millar

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## richard.scott

Are you saying that your serial socket on the switch is a rj45 socket? Like the ones you get on a Sun Solaris Server?

If that is the case then its not really ethernet (as in you can't give it an IP) so I don't believe it will work in the way you want.

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## mattmill30

Hi Richard,

No, I was meaning, is it possible to allow software to use a computers RJ45 port as a serial port, because the switch has a Serial connection, and requires a remote console/terminal to administrate it, and I only have an RJ45-Serial

Basically, i'm looking to create something like a loop, between a virtual serial device and a physical RJ45 port, so that if i find a piece of software which supports serial-serial terminal, i can direct it to the virtual serial port, and it'll in actual fact pass the data to/from the RJ45 cable, which will allow communication to the serial port on the switch.

Hope that makes sense.

Thanks,

Matthew Millar

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## ccp

 *mattmill30 wrote:*   

> 
> 
> No, I was meaning, is it possible to allow software to use a computers RJ45 port as a serial port, because the switch has a Serial connection, and requires a remote console/terminal to administrate it, and I only have an RJ45-Serial
> 
> Basically, i'm looking to create something like a loop, between a virtual serial device and a physical RJ45 port, so that if i find a piece of software which supports serial-serial terminal, i can direct it to the virtual serial port, and it'll in actual fact pass the data to/from the RJ45 cable, which will allow communication to the serial port on the switch.
> ...

 

Hi, 

I guess you want to remote manage your switch. And have a computer with serial port available to connect to the switch. but you prefer from your desktop or manage console connect direct in to the switch without first hop on to the in-between computer right?

If I am right then you can try app-admin/conserver. which let you do run the in-between computer as terminal server.

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## mattmill30

Hi ccp,

I'll give those packages a try tomorrow, thanks.

Basically, i have a pc with no serial port, i want to use an RJ45 instead of a serial, i have a RJ45-serial cable, I need to connect to a serial port on a switch.

Theres no way i can use a serial port on my computer, hence why i'll need to emulate one over a physical RJ45 port.

Does that make sense? Or am i talking nonsense?

Thanks,

Matthew Millar

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## ccp

 *mattmill30 wrote:*   

> Hi ccp,
> 
> I'll give those packages a try tomorrow, thanks.
> 
> Basically, i have a pc with no serial port, i want to use an RJ45 instead of a serial, i have a RJ45-serial cable, I need to connect to a serial port on a switch.
> ...

 

In this case you do not need to try the package, it will not work for you. You can buy a serial port card then use the package to help remote connect your switch.

from your description it sure hard to understand what is you trying.

A serial port usually is base on RS232 or RS432?(not very sure the number) which IEEE standard define each wire have what kind of signal.

A RJ45 is refer to a specific kind of connector which use mostly in network or telecom world.

So the two have no direct relationship, a serial port can have RJ45 connector for example or it can hve DB9 or DB25 as connector. it is the signal running on the wire define what the type of link.

Your pc may have a RJ45 connector which usually is for ethernet which define different signals on wire, they can not be connect to serial port because the serial port expect different kind of signal on wire.

when you said you want to make virtual serial device which usually in the  OSI model refer as layer 7 application, a serial port is refer as layer 1/2, so unless you can achieve all the lower layer you will not able to make virtual device.

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## richard.scott

do you have a USB port? If so, get a USB->Serial adapter.

or, if you have buletooth, get a Bluetooth -> Serial adapter

Trouble with that is both will need a DB9 -> RJ45 adapter to get it to talk to the switch.

Sometimes tho, a standard network cable doesn't work there as you may need a specific cable from the makers of the switch. I believe Cisco needs a special blue cable? so it wouldn't work with what equipment you have.

Rich.

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## mattmill30

Hi,

Thanks for the replies

It looks like i'll need to buy a new serial-serial cable.

Essentially what i was hoping to do was use an RJ45-Serial cable by plugging the RJ45 end into my pc and the Serial end into my switch.

Obviously the issue that i then have is how do i get software to treat the computers RJ45 port as a serial port so that it can communicate with the switch.

I was expecting to have to adapt the ethernet driver to accept serial requests and register itself as a serial port.

I know its pointless when i can buy a cable, but how else do u expand ur knowledge/abilities?

If anyone has any more ideas, i'd be greatful to hear them.

Thanks,

Matthew Millar

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