Last Modified: Mar 17, 2021
See more info
Known Affected Versions:
11.6.0, 11.6.0 HF1, 11.6.0 HF2, 11.6.0 HF3, 11.6.0 HF4, 11.6.0 HF5, 11.6.0 HF6, 11.6.0 HF7, 11.6.0 HF8, 11.6.1, 11.6.1 HF1, 11.6.1 HF2, 11.6.2, 11.6.2 HF1, 11.6.3, 188.8.131.52, 184.108.40.206, 220.127.116.11, 18.104.22.168, 11.6.4, 11.6.5, 22.214.171.124, 126.96.36.199, 188.8.131.52
Opened: Sep 11, 2014
Related AskF5 Article: K17194
When NAT-T is ON in the IKE-peer configuration on the BIG-IP system, but there is no NATing in the network, IKE negotiation succeeds and brings up SAs correctly. But IPsec (ESP) packets will not pass because of a mismatch in the expected port number (4500 rather than 500) while receiving ESP packets.
IPsec packets are dropped and traffic loss.
NAT_T is ON on the BIG-IP system and there is no NATing in the network.
Do not configure NAT on the BIG-IP system if there is no NATing in the network.
NAT-T is configured but there is no NAT in the network, IPsec now works as expected.