[NTLUG:Discuss] OT: console server

[Chris Cox]

Fred James wrote:
> Stuart Johnston wrote:
> 
>> Fred James wrote:
>>  
>>
>>> Stuart Johnston wrote:
>>>
>>>    
>>>
>>>> Fred James wrote:
>>>>
>>>>
>>>>      
>>>>
>>>>> All
>>>>> I have four UNIX boxes sitting together, that I should like to be able 
>>>>> to telnet to a console server for (male DB9 serial ports), and I should 
>>>>> appreciate any suggestions toward a cost effective solution - I don't 
>>>>> need GUI, color, or any thing fancy like that.  Thank you in advance for 
>>>>> any help you may be able to offer.
>>>>>   
>>>>>
>>>>>        
>>>>>
>>>> I don't have any actual experience doing this but from what little I know, you can either:
>>>>
>>>> 1) Buy a console server from someone like Cyclades for ~$800
>>>>
>>>> 2) Buy a 4-port serial card (~$100) and setup a linux system to act as the console server.
>>>>
>>>>
>>>>      
>>>>
>>> Stuart Johnston
>>> 4-port serial card?  Are those manufacturer, OS, BIOS, or any such 
>>> dependent?  For example, I have available for the experiment a spare HP 
>>> Pavilion 6630 (Intel Celeron 500MHz. 64 MB SDRAM, 10.2 GB hard drive, 
>>> CD-ROM and floppy).
>>>    
>>>
>> I think they are pretty standard.  Come to think of it, since you only need 4 ports and your PC may 
>> already have 2, you could just get a dual board which are cheap and easy to find.  Or even 2 dual 
>> boards would probably work if the PC doesn't have any.
>>
>> For example:
>>
>> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220010362033
>>  
>>
> Stuart Johnston
> Sorry to be such a bother, but I have never used any of these, so ... 
> any IRQ or address issues ... for example, I can open multiple telnet 
> sessions to the box with the extra serial ports, would I be able to 
> address all of the serial ports at once (one for each telnet session, up 
> to at least a max of one session per serial port)?
> Regards
> Fred James
> 

The Cyclades is a standalone subsystem.  It connects to your
network.  For outside access either you place the unit where
it can be reached via tcp/ip... or you can even hook up a
modem (e.g. a callback modem) for true out of band.

You connect to each port via ssh or telnet, but ssh is
preferred (for security).

So... you connect the serial consoles of your Linux
boxes to the Cyclades and then let's assume you want
to reach it via tcp/ip.  If the cyclades unit is called
braunsdorf, you would use:

ssh username:portname at braunsdorf

Optionally, username would have a password, once authenticated
you would be on the serial device connected to "portname".
I usually attached the actual console to the serial
device, so I would get a login prompt off of the main
console tty.  You assign different usernames to different
ports, etc.  So you can restrict which consoles can
be accessed by what individuals. You can configure
baud rates, etc.... I prefer 115200 if your servers
can handle it.  But sometimes older stuff might force
you to use 9600... all configurable.

Many server boxes (e.g. Dell/HP) will allow you to
route even the BIOS startup out through the serial
port... so you can even get to that.

Configured correctly, you can change your entire
network around with no problem even remotely using
the cyclades unit.