Dual-WAN for simple round-robin load equalization
From DD-WRT Wiki
[edit] Introduction
(copied from forum-posting by user aldoir Dual-WAN forum posting
You'll need to create a new VLAN, called vlan2.
Enter in the web interface, Settings/VLANs. Set Port 4 to a new VLAN.
Enter in the console, and do the following commands
commands to set VLANs
nvram set vlan0ports="1 2 3 5*" nvram set vlan2ports="4 5" nvram set vlan2hwname=et0 nvram commit
Here are the scripts I used to startup the interface. You need to call them in rc_firewall
wan2.firewall
//edit - dont like this bit, it doesnt seem to be for DHCP connection and looks like its for a static IP connection
#!/bin/sh WAN2_IFNAME=vlan2 WAN2_IPADDR=10.0.0.2 WAN2_GATEWAY=10.0.0.1 WAN2_NETMASK=255.0.0.0 if [ "$(nvram get wan2_ipaddr)" != "$WAN2_IPADDR" ]; then nvram set wan2_ifname=$WAN2_IFNAME nvram set wan2_ipaddr=$WAN2_IPADDR nvram set wan2_gateway=$WAN2_GATEWAY nvram set wan2_netmask=$WAN2_NETMASK nvram commit fi ifconfig $(nvram get wan2_ifname) up $(nvram get wan2_ipaddr) netmask $(nvram get wan2_netmask)
routes.firewall
#!/bin/sh ip rule flush ip rule add lookup main prio 32766 ip rule add lookup default prio 32767 ip rule add from $(nvram get wan_ipaddr) table 100 prio 100 ip rule add fwmark 0x100 table 100 prio 101 ip rule add from $(nvram get wan2_ipaddr) table 200 prio 200 ip rule add fwmark 0x200 table 200 prio 201 ip route flush table 100 ip route flush table 200 for TABLE in 100 200 do ip route | grep link | while read ROUTE do ip route add table $TABLE to $ROUTE done done ip route add table 100 default via $(nvram get wan_gateway) ip route add table 200 default via $(nvram get wan2_gateway)
firewall.firewall
#!/bin/sh #DD-WRT firewall rules #BEGIN #apply simple forward rules for RULE in $(nvram get forward_spec) do FROM=`echo $RULE | cut -d '>' -f 1` TO=`echo $RULE | cut -d '>' -f 2` STATE=`echo $FROM | cut -d ':' -f 2` PROTO=`echo $FROM | cut -d ':' -f 3` SPORT=`echo $FROM | cut -d ':' -f 4` DEST=`echo $TO | cut -d ':' -f 1` DPORT=`echo $TO | cut -d ':' -f 2` if [ "$STATE" = "on" ]; then if [ "$PROTO" = "both" ]; then #udp #iptables -A FORWARD -d $(nvram get wan2_ipaddr) -p udp --dport $SPORT -j ACCEPT iptables -A PREROUTING -t nat -p udp -d $(nvram get wan2_ipaddr) --dport $SPORT -j DNAT --to $DEST:$DPORT #tcp #iptables -A FORWARD -d $(nvram get wan2_ipaddr) -p tcp --dport $SPORT -j ACCEPT iptables -A PREROUTING -t nat -p tcp -d $(nvram get wan2_ipaddr) --dport $SPORT -j DNAT --to $DEST:$DPORT else #iptables -A FORWARD -d $(nvram get wan2_ipaddr) -p $PROTO --dport $SPORT -j ACCEPT iptables -A PREROUTING -t nat -p $PROTO -d $(nvram get wan2_ipaddr) --dport $SPORT -j DNAT --to $DEST:$DPORT fi fi done #apply range forward rules for RULE in $(nvram get forward_port) do FROM=`echo $RULE | cut -d '>' -f 1` TO=`echo $RULE | cut -d '>' -f 2` STATE=`echo $FROM | cut -d ':' -f 2` PROTO=`echo $FROM | cut -d ':' -f 3` SPORT=`echo $FROM | cut -d ':' -f 4` EPORT=`echo $FROM | cut -d ':' -f 5` if [ "$STATE" = "on" ]; then if [ "$PROTO" = "both" ]; then #udp #iptables -A FORWARD -d $(nvram get wan2_ipaddr) -p udp --dport $SPORT:$EPORT -j ACCEPT iptables -A PREROUTING -t nat -p udp -d $(nvram get wan2_ipaddr) --dport $SPORT:$EPORT -j DNAT --to $TO #tcp #iptables -A FORWARD -d $(nvram get wan2_ipaddr) -p tcp --dport $SPORT:$EPORT -j ACCEPT iptables -A PREROUTING -t nat -p tcp -d $(nvram get wan2_ipaddr) --dport $SPORT:$EPORT -j DNAT --to $TO else #iptables -A FORWARD -d $(nvram get wan2_ipaddr) -p $PROTO --dport $SPORT:$EPORT -j ACCEPT iptables -A PREROUTING -t nat -p $PROTO -d $(nvram get wan2_ipaddr) --dport $SPORT:$EPORT -j DNAT --to $TO fi fi done iptables -A PREROUTING -t nat -p icmp -d $(nvram get wan2_ipaddr) -j DNAT --to $(nvram get lan_ipaddr) if [ $(nvram get remote_management) -eq 1 ]; then iptables -A PREROUTING -t nat -p tcp -d $(nvram get wan2_ipaddr) \ --dport $(nvram get http_wanport) -j DNAT --to $(nvram get lan_ipaddr):$(nvram get http_lanport) fi if [ $(nvram get dmz_enable) -eq 1 ]; then DMZ_IP=$(nvram get lan_ipaddr | sed -r 's/[0-9]+$//')$(nvram get dmz_ipaddr) iptables -A PREROUTING -t nat -d $(nvram get wan2_ipaddr) -j DNAT --to $DMZ_IP fi iptables -A PREROUTING -t nat --dest $(nvram get wan2_ipaddr) -j TRIGGER --trigger-type dnat iptables -A FORWARD -i $(nvram get wan2_ifname) -o $(nvram get lan_ifname) -j TRIGGER --trigger-type in iptables -A PREROUTING -t mangle -i $(nvram get wan2_ifname) -j IMQ --todev 0 iptables -A PREROUTING -t mangle -i $(nvram get wan2_ifname) -j SVQOS_IN iptables -A POSTROUTING -t mangle -o $(nvram get wan2_ifname) -j SVQOS_OUT #DD-WRT END #Save the gateway in the connection mark for new incoming connections iptables -t mangle -A PREROUTING -i $(nvram get wan_ifname) -m conntrack --ctstate NEW -j CONNMARK --set-mark 0x100 iptables -t mangle -A PREROUTING -i $(nvram get wan2_ifname) -m conntrack --ctstate NEW -j CONNMARK --set-mark 0x200 # Save the gateway in the connection mark for new outgoing connections iptables -t mangle -A POSTROUTING -o $(nvram get wan_ifname) -m conntrack --ctstate NEW -j CONNMARK --set-mark 0x100 iptables -t mangle -A POSTROUTING -o $(nvram get wan2_ifname) -m conntrack --ctstate NEW -j CONNMARK --set-mark 0x200 # Use the correct gateway for reply packets from the LAN iptables -t mangle -A PREROUTING -i $(nvram get lan_ifname) -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark # Use the correct gateway for reply packets from local connections iptables -t mangle -A OUTPUT -m conntrack --ctstate ESTABLISHED,RELATED -j CONNMARK --restore-mark #mask known packets to its source address iptables -A POSTROUTING -t nat -m mark --mark 0x100 -j SNAT --to-source $(nvram get wan_ipaddr) iptables -A POSTROUTING -t nat -m mark --mark 0x200 -j SNAT --to-source $(nvram get wan2_ipaddr) #permit access to wan2 iptables -A POSTROUTING -t nat -j MASQUERADE -o $(nvram get wan2_ifname) #restore-mark is done in PREROUTING. If restored again, will loose the outgoing marks iptables -t mangle -D SVQOS_OUT -j CONNMARK --restore-mark 2> /dev/null #iptables -t mangle -A PREROUTING -i $(nvram get lan_ifname) -m multiport -p tcp --dport 22,25,80,110,119,143,443,993,3389 -j MARK --set-mark 0x100 #use WAN1 for common navigation, WAN2 for P2P traffic and others #iptables -t mangle -I PREROUTING -i $(nvram get lan_ifname) -s 192.168.1.100 -j MARK --set-mark 0x200 #iptables -t mangle -I PREROUTING -i $(nvram get lan_ifname) -s 192.168.1.100 -j LOG --log-prefix 'P2P: ' RP_PATH=/proc/sys/net/ipv4/conf for IFACE in `ls $RP_PATH`; do echo 0 > $RP_PATH/$IFACE/rp_filter done
Once everything works, you should use the command ' ip route equalize' (search with Google for the syntax) to balance the load, or do a -j MARK --set-mark 0xN00 via iptables to redirect your traffig to WAN1 (0x100) or WAN2 (0x200)
If you need further assistance, post in forums or PM-me
The firewall scripts does not yet implement the full DD-WRT firewall, only the basic port/range forwarding.
This is script works for both outgoing AND incoming connections (most scripts only treats outgoing), so you should be able to accept connections in both links simultaneous (eg. web in one and FTP in another).