Hi caulfiedd@live.cn ,
By default , NAT-traversal is enabled on SRX.
so during messages 3 and 4 , NATT payload are exchanged between 2 peers.
Nat Traversal (NATT) has to be enabled on both Peers so that ESP packets can be encapsulated within UDP header to pass through NAT device.
Regards,
rparthi
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