How to setup IPSEC tunnel with Watchguard Firebox with NAT-T enabled



  • Hello,

    I currently have an IPSec tunnel setup between by pfSense 2.0 RC3 and a Watchguard Firebox.  The tunnel seems to be unstable, and the last time it went down I noticed the pfSense firewall was blocking UDP traffic on port 4500 - I believe UDP port 4500 is Nat-Traversal.

    I currently have a firewall rule on the WAN interface allowing UDP 500 traffic, do I also need to add a rule allowing UDP port 4500 traffic?

    Thanks,

    Todd



  • @ttblum:

    do I also need to add a rule allowing UDP port 4500 traffic?

    That depends on if you are using NAT-T.

    Look in your tunnel configuration to see if you have NAT Traversal enabled in pfSense.  It is in the advanced options at the bottom of the phase 1 policy.

    If both firewalls have NAT-T on, then you will need to allow access over UDP 4500, or disable it on both.


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