MWAN with netifd

• This instruction configures multi-WAN with netifd on OpenWrt.
• Enable IPv6 NAT or NPT and disable IPv6 source filter if necessary.
• Follow PBR with netifd for setting up PBR.

• Implement multi-WAN based on PBR with netifd.
• Perform connectivity check with ICMP and ICMPv6.
• Provide a simple failover method.
• Support dual-stack setups.

Assuming pre-configured upstream interfaces wana and wanb. Set up PBR with netifd. Save the failover script. Configure cron to run the failover script.

# Configure network
cat << EOF >> /etc/iproute2/rt_tables
1 wana
2 wanb
EOF
for IPV in 4 6
do
uci set network.wana${IPV%4}.ip${IPV}table="wana"
uci set network.wanb${IPV%4}.ip${IPV}table="wanb"
uci -q delete network.default${IPV%4}
uci set network.default${IPV%4}="rule${IPV%4}"
uci set network.default${IPV%4}.lookup="wana"
uci set network.default${IPV%4}.priority="80000"
done
uci commit network
/etc/init.d/network restart
 
# Failover script
cat << "EOF" > /root/mwan.sh
NET_IF="wana"
NET_FIF="wanb"
NET_IF6="${NET_IF}6"
. /lib/functions/network.sh
network_flush_cache
network_get_device NET_DEV "${NET_IF}"
network_get_device NET_DEV6 "${NET_IF6}"
network_get_gateway NET_GW "${NET_IF}"
network_get_gateway6 NET_GW6 "${NET_IF6}"
for IPV in 4 6
do if ping -q -c 3 -w 5 -I \
"$(eval echo \${NET_DEV${IPV%4}})" \
"$(eval echo \${NET_GW${IPV%4}})" &> /dev/null
then NET_RT="${NET_IF}"
else NET_RT="${NET_FIF}"
fi
NET_CRT="$(uci -q get network.default${IPV%4}.lookup)"
if [ "${NET_RT}" != "${NET_CRT}" ]
then logger -t mwan "Switching to ${NET_RT}"
uci set network.default${IPV%4}.lookup="${NET_RT}"
/etc/init.d/network reload
fi
done
EOF
 
# Configure cron
cat << "EOF" >> /etc/crontabs/root
* * * * * . /root/mwan.sh
EOF
uci set system.@system[0].cronloglevel="9"
uci commit system
/etc/init.d/cron restart