Thanks for replying, Russ. Honestly, I do not know if this will give me the level of VPN availability I currently enjoy when using both MX WAN interfaces connected to separate ISPs. Unless I could perhaps try to do some Policy Based Routing on the "other" firewall" to allow each WAN interface of the MX to route out through a different ISP interface of the other firewall thus maintaining multiple VPN connections between the MX and the remote sites. Possible you think?