L2TP passthrough

Discussion in 'Tomato Firmware' started by Lacertadeus, Dec 22, 2017.

  1. Lacertadeus

    Lacertadeus New Member Member

    I have been searching for better part of 3 hours and tried a dozen scripts and router configurations. I have a RRAS server inside an advanced tomato firewall. I am trying to get a L2TP vpn to pass through the firewall but it will not.
    I have tried DMZ, I am forwarding ports UDP 500 and 4500

    I think the problem is with ESP and AH not passing along, but I can't get them to work. This is the latest version of the script I'm using, not sure what else to try. Suggestions? Thanks in advance

    iptables -t nat -I PREROUTING -p udp --dport 500 -j DNAT --to 192.168.0.3:500
    iptables -I FORWARD -p udp -d 192.168.0.3 --dport 500 -j ACCEPT
    iptables -t nat -I PREROUTING -p udp --dport 4500 -j DNAT --to 192.168.0.3:4500
    iptables -I FORWARD -p udp -d 192.168.0.3 --dport 4500 -j ACCEPT
    iptables -t nat -I PREROUTING -p 50 -j DNAT --to 192.168.0.3
    iptables -I FORWARD -p 50 -d 192.168.0.3 -j ACCEPT
    iptables -t nat -I PREROUTING -p 51 -j DNAT --to 192.168.0.3
    iptables -I FORWARD -p 51 -d 192.168.0.3 -j ACCEPT
    iptables -A FORWARD -p esp -d 192.168.0.3 -j ACCEPT
    iptables -A FORWARD -p ah -d 192.168.0.3 -j ACCEPT
     
  2. Sean B.

    Sean B. LI Guru Member

    I would suggest using tcpdump on the router ( or rpcapd with remote capture Wireshark ) and track your packet flows. It should be rather easy to spot where things go wrong.
     
  3. eibgrad

    eibgrad Network Guru Member

    Does the syslog provide any useful information?
     
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