Serial Line Internet Protocol or SLIP is a protocol that enables internet like calls over a serial connection (ex: UART, RS232, RS422). This tutorial assumes you have two Raspberry Pi's (RPI-1, RPI-2). The csmos_slip library lets you use SLIP protocol with IP packets. It is used be Cosmos_Serial library to support SLIP protocol over serial.
Setting up slip on RPI-1
# enter this on /etc/network/interfaces
# SLIP configuration for RPI-1
auto sl0
iface sl0 inet static
address 192.168.1.1
netmask 255.255.255.0
pointopoint 192.168.1.2
pre-up slattach -s 115200 -p cslip -L /dev/ttyS2 &
post-up route add 192.168.1.1 dev lo
Setting up slip on RPI-2
# enter this on /etc/network/interfaces
# SLIP configuration for RPI-2
auto sl0
iface sl0 inet static
address 192.168.1.2
netmask 255.255.255.0
pointopoint 192.168.1.1
pre-up slattach -s 115200 -p cslip -FL /dev/ttyS3 &
post-up route add 192.168.1.2 dev lo
Other resources: