With OPT_PPP='yes' a computer can be connected via its serial interface. This may be useful i.e. for connecting computers to a network that does not have a network interface card. The computer connected to the serial interface is called client PC below.
Specify fli4l's serial interface the client PC is connected to. Possible values are:
'com1' | COM1 port (lower cases only!) | |
'com2' | COM2 port (lower cases only!) |
Set transfer rate here (bit/sec). 38400 is supported by older interfaces too. Problems may occur when using rates above this.
Example: PPP_SPEED='38400'
PPP_IPADDR holds fli4l's IP address on the COM port, i.e. '192.168.4.1'. In variable PPP_PEER the IP address of the client PC is set, i.e. '192.168.4.2'.
PPP_NETWORK holds the network used and variable PPP_NETMASK the netmask. These two variables are used by the extra package 'samba_lpd'.
Important: Consider the following:
Causes:
If telnet or ftp should be used from the client PC to the fli4l router the daemons concerned on fli4l do a reverse DNS lookup to resolve the client PC. If it is not found in the host table a connection to the Internet will be established to do this - which is of course useless. To avoid this enter the client PC in the host table.
Example for PPP Configuration over the serial interface:
PPP_DEV='com1' PPP_SPEED='38400' PPP_IPADDR='192.168.4.1' PPP_PEER='192.168.4.2' PPP_NETWORK='192.168.4.0' PPP_NETMASK='255.255.255.0'
and further on in config/base.txt:
MASQ_NETWORK='192.168.6.0/24 192.168.4.0/24'
The first network number is the one of the ethernet LAN and the second the one of the PPP network.
As long as there is no other net in the 192.168. range in use both nets can be joined in MASQ_NETWORK. This simplifies configuring firewall rules.
In this case use:
MASQ_NETWORK='192.168.0.0/16'
this masks every net starting with 192.168.
Last thing is to adapt DNS Configuration. Example:
HOST_5='192.168.4.2 serial-pc'
Do not forget to increment HOST_N!
If the client PC is running Windows you have to configure the dial-up adapter for a PPP connection to the fli4l router.
If a linux client is used create a shell script on the client (i.e. /usr/local/bin/ppp-on):
#! /bin/sh dev='/dev/ttyS0' # COM1, for COM2: ttyS1 speed='38400' # speed options='defaultroute crtscts' # options myip='192.168.4.2' # IP address client fli4lip='192.168.4.1' # IP address fli4l router pppd $dev $speed $options $myip:$fli4lip &
In case of problems: man pppd
The fli4l router has to be used as the DNS server on the client if a connection to the Internet is desired. Add two lines to /etc/resolv.conf on the client: the domain used and the ethernet IP address of the fli4l router as name server.
Example:
search domain.de nameserver 192.168.1.4
“domain.de” res. “192.168.1.4” have to be changed to your needs. Important: The IP address has to be the one of fli4l's ethernet card!
A so called null modem cable is used as the physical connection. See appendix for package base for pin wirings.
A (german) Howto for connecting a Windows client with serial PPP can be found at:
http://www.fli4l.de/hilfe/howtos/basteleien/opt-ppp-howto/