RFC 8229, "TCP Encapsulation of IKE and IPsec Packets", August 2017Source of RFC: ipsecme (sec)
Errata ID: 5320
Publication Format(s) : TEXT
Reported By: Valery Smyslov
Date Reported: 2018-04-09
Throughout the document, when it says:
It should say:
TCP provides reliable transport, so there is no need for applications to deal with retransmissions. Moreover, sending retransmissions by IKE in case of TCP on congested networks could further increase congestion and degrade performance. For this reason IKE initiators SHOULD NOT retransmit requests if they are sent over TCP. However, both IKE initiators and responders MUST correctly handle retransmitted messages received over TCP, but responders SHOULD NOT resend response messages in this case. If IKE initiators still choose to retransmit requests over TCP, then the retransmission policy SHOULD be less aggressive than it would have been in case of UDP.
While Section 12.2 discusses some implications that TCP transport could have on ESP protocol, the IKE retransmission behavior, described in Section 2.1 of RFC7296, is not redefined by this RFC. This is an oversight and some recommendations for implementers should have been given. The suggested text should be placed in a new section, presumably between sections 8 and 9.