Dual Stack Failover force IPv4 only?



  • Hi!

    I have two ISP running Dual WAN as failover with Dual Stack. Is there a way to disable IPv6 if WAN1 fails and running IPv4 only over WAN2?
    Problem is that I have set my LAN to Track Interface WAN1 and if WAN1 fails (Packet Loss) the clients still want to use IPv6 over WAN1 but fail.


  • Rebel Alliance Developer Netgate

    No, that is not currently possible. The clients would have to somehow know not to send IPv6 anymore. Even if pfSense stopped advertising itself as a router that wouldn't solve the whole problem.



  • But I got it running :) The workaround is to unmonitor (always up) the IPv6 Gateway from WAN2 and then disable IPv6 on WAN2. If WAN1 fails, it switches to WAN2 but the clients doesn't receive anything over IPv6 so they change instant to IPv4.



  • ^^^^
    And in the process you've lost IPv6 entirely, which is dumb as that's where the world is moving to.  Perhaps it would have been better to set up a 6in4 tunnel as backup for IPv6.  Many people use he.net for that.