Thanks for the link. Sounds like we should be good with the MX then since we would be using NAT xlates for that secondary subnet. As long as the MX will answer the ARP requests from the provider we should be fine.   I just didnt want to rely on  the ISP to change their configuration to accommodate us. Since worst case i could look at having the remove the secondary configuration on their interface so its not seen as "connected" and instead have them actually put in a route statement to our MX for the secondary range. ... View more