Debian VPNC split tunneling (add it to the `vpnc.conf` with the `Script` option)

vpnc-split.sh

#!/bin/sh

# Add one IP to the list of split tunnel
add_ip ()
{
	export CISCO_SPLIT_INC_${CISCO_SPLIT_INC}_ADDR=$1
	export CISCO_SPLIT_INC_${CISCO_SPLIT_INC}_MASK=255.255.255.255
	export CISCO_SPLIT_INC_${CISCO_SPLIT_INC}_MASKLEN=32
	export CISCO_SPLIT_INC=$(($CISCO_SPLIT_INC + 1))
}

# Initialize empty split tunnel list
export CISCO_SPLIT_INC=0

# Delete DNS info provided by VPN server to use internet DNS
# Comment following line to use DNS beyond VPN tunnel
unset INTERNAL_IP4_DNS

# List of IPs beyond VPN tunnel
# see /etc/hosts for hostnames
add_ip 127.0.0.1
# Add more IPs here like above

# Execute default script
. /usr/share/vpnc-scripts/vpnc-script

# End of script