[RESOLVED] Outbound NAT not working on BGP Internet connection



  • I am setting up a BGP Internet connection using openBGPD.  The WAN network is up and running, but any and all NAT is not being applied to outbound traffic.

    In the States table, it is showing my LAN PC attempting to ping 4.2.2.2 directly instead of through a NAT IP.  The State is 0:0 (instead of established).  Other states connecting across the Internet sho NO_TRAFFIC:SINGLE. 
    This was a functional network on the old WAN network with a normal routed gateway, etc.

    Is there a setting required to force NAT to be applied when leaving the network through a BGP connection?  Is it not seeing the BGP/WAN interface as an actual external interface?  It seems like it is treating the BGP WAN network as local.



  • Resolved.

    BGP connection: em0
    LAN connection: em1
    Announced WAN connection: em2 (Routed WAN block Class C)

    The VIP assigned is WAN IP 62.55.55.1 (CARP) on interface em2.
    The Outbound NAT interface should be the BGP interface em0.

    • NAT Translation address should select the VIP 62.55.55.1 (which is assigned on em2).

    The NAT translation problem was caused by the NAT interface being assigned em2 which is the routed class C network.  Changing the NAT interface to the BGP interface em0 resolved the problem.