On Wed, Feb 24, 2021 at 06:01:19PM +0000, tincanteksup wrote: > today I discovered that a server using TCP responds to an initial Syn packet > with an ack packet,
This is standard TCP protocol (SYN, SYN ACK, ACK). It is executed in the kernel. Only after the client ACK is received by the server will OpenVPN handle that TCP connection (accept(2) returns a new connection socked in the ESTABLISHED state). Before that, OpenVPN does not even know a connection is being opened. > even with --tls-auth key configured. This, TCP does not know. For TCP, it's just data bytes. The TLS negociation is done afterwards, when the TCP connection was established. _______________________________________________ Openvpn-users mailing list Openvpn-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openvpn-users
