openvpn.conf

config openvpn 'myvpn'
	option dev 'tun'
	option topology 'subnet' # This is important
	option comp_lzo 'adaptive'
	option ca '/etc/openvpn/ca.crt'
	option dh '/etc/openvpn/dh.pem'
	option cert '/etc/openvpn/server.crt'
	option key '/etc/openvpn/server.key'
	option persist_key '1'
	option persist_tun '1'
	option user 'nobody'
	option group 'nogroup'
	option max_clients '10'
	option keepalive '10 120'
	option verb '3'
	option status '/var/log/openvpn_status.log'
	option push 'dhcp-option DNS 192.168.1.2' # Push your gateway (旁路由) IP address
	option client_connect '/etc/openvpn/push_routing_rule' # Must push this rule
	option script_security '2'
	option log '/var/log/openvpn_multiple_client.log'
	option proto 'udp4'
	option port '12345' # your openvpn port. Remember to add a port forwarding rule on your main router
	option ddns '[your_ddns_domain]' # If not set, you could also use your public IP
	option server '10.0.2.0 255.255.255.0'
	option mssfix '1420'
	option client_to_client '1'
	option enabled '1'
	option duplicate_cn # allow multiple-clients (can be turned off)

push_routing_rule

#!/bin/sh

echo push \"route-delay 10\" > $1
echo push \"route 192.168.1.0 255.255.255.0 $ifconfig_pool_local_ip\" >> $1
echo push \"route 10.0.2.0 255.255.255.0 $ifconfig_pool_local_ip\" >> $1
echo push \"redirect-gateway def1\" >> $1


# Note:
# `192.168.1.0` is the IP range of the DHCP service on your main router
# `10.0.2.0` is the IP range of your OpenVPN service
# Please adjust the above two IP addresses