my MT box has 2 isp connections, say wan_1 and wan_2, and i have setup LT2P server in MT box already.
wan_1 has 8 public ip 1.1.1.1 - 1.1.1.8
wan_2 has 8 public ip 2.2.2.1 - 2.2.2.8
my problem is:
L2TP sever can only listen on wan_1 ip 1.1.1.1, if listen on others public ip ( 1.1.1.2 - 1.1.1.8 ) client cannot connect
L2TP server cannot listen on wan_2 any public IP ( 2.2.2.1 - 2.2.2.8 )
i think that MT always suppose to use first wan interface (wan_1), and first public ip ( 1.1.1.1 ) to serve for L2TP even PPTP clients, could anyone confirm this problem?
Very well maybe that it only listens on the first IP address listed. just like NAT masqurading only works on the first IP of the interface ,even if you have multiple connections.
Maybe try to have the server be a client out the second connection, then run OSPF between the two, each box has a client and server to keep the ocnnection, OSPF should give you failover.
Actually, it is based on the source IP of the return packets.
If you attempt to establish a tunnel to an IP on your router, which is not the IP it will source the response from, many clients (including windows) will get confused, and it will fail.
You can solve this by making sure that l2tp/pptp responses will always come from a specific IP, and then only establish tunnels to that IP. Routing-test helps a lot this way, with set-prefsrc=. Same technique is also useful for normalising Radius requests.