Forum Discussion

diego2's avatar
diego2
Icon for Altostratus rankAltostratus
Feb 10, 2026
Solved

TCP Profile with Verified Accept enabled and three-way TCP handshake

Hi, I'm trying to understand exactly how the Standard virtual server processes connections using the full proxy architecture works when Verified Accept is enable on the TCP profile. With Verified A...
big-ip
LTM
tcp profile
diego2's avatar
diego2
Icon for Altostratus rankAltostratus
Feb 11, 2026

Hi Jose, thank you for your reply.

The client does not receive a SYN-ACK until the selected pool member has successfully responded to the SYN, ok. But the ACK to the pool member that complete the three-way server-side handshake is sent before or after the SYN-ACK to the client ? 

Is the SYN-ACK that the server sent to reply to the SYN of the Big IP the guarantee that the connection is accepted ? 

If the server-side three-way handshake occurs before the client-side three-way handshake, what it means that :

Verified Accept enabled: CLIENT_ACCEPTED -> LB_SELECTED -> SERVER_CONNECTED -> HTTP_REQUEST -> HTTP_REQUEST_SEND

 

Thanks

 

zamroni777's avatar
zamroni777
Icon for MVP rankMVP
Feb 13, 2026

with verified accept: server side 3 way handshake completes before f5 replies SYN-ACK to client's SYN

  • diego2's avatar
    diego2
    Icon for Altostratus rankAltostratus
    Feb 13, 2026

    Ok, thank you for you reply.

    So, could you help me understand exactly what that means

    CLIENT_ACCEPTED -> LB_SELECTED -> SERVER_CONNECTED -> HTTP_REQUEST -> HTTP_REQUEST_SEND

     

    Thanks