After having configured the server, the client is easy. The "/etc/ppp/options" file has a single entry:
The serial port on my client is "/dev/ttyS0" (COM1), so I also have to create a "/etc/ppp/options.ttyS0" file:
#/etc/ppp/options.ttyS0 115200 crtscts local user zaphod noauth
Only a few new options in this file. Note that the speed on server and client has to be the same (here it is 115200). With "user zaphod" the client user name is specified. This user name has to correspond to an entry in the "/etc/ppp/pap-secrets" file of the client and has to be a valid user name on the server. The "noauth" option specifies that the peer (server) does not have to authenticate itself to the client.
The last bit: setting the client name (user name) and its secret (password) in the "/etc/ppp/pap-secrets" file:
#/etc/ppp/pap-secrets # Secrets for authentication using PAP # client server secret IP addresses zaphod * gargleBlaster
So user "zaphod" uses a password "gargleBlaster", which should get him into the system. Note that these files contain sensitive information, make sure you set the permissions on them correctly.
On the command line, type:
/usr/sbin/pppd /dev/ttyS0 nodetach
What if you want to make a connection to a Windows server? Again we'll need the "connect" option and a chat script. Add the following line to your "/etc/ppp/options.ttyS0" file:
connect chat -v -f /etc/ppp/scripts/winserver.chat
Also create the chat script "/etc/ppp/script/winserver.chat":
TIMEOUT 10 '' CLIENT\c
This makes the client send the "CLIENT" string before trying to start the PPP connection.
To connect to the server using windows, you use the Direct Cable Connection program, and set it up as "guest". In order for the windows client to connect at full speed (or at all), you will have to change the communication speed of direct cable connection. To do this, go to Control Panel->System->Device Manager->Modems and select the serial cable. Proceed to the 'modem' option and select a maximum speed of 115200 or whatever your linux computer is set to. Now, it is important that you reboot at this stage, or it WILL NOT WORK (at least with Microsoft windows 95 version A), I am not sure about others.
Oddly enough I created a Linux server that has to connect to both Linux and Windows computers, so I found myself with the odd situation of having to setup both Linux systems such that they would connect to Windows servers and clients!