ssh-agent, protocol 2, openssh-2.3.0p1

[Roumen Petrov]

What protocol version use ssh-agent from OpenSSH.

local:'SSH Version OpenSSH_2.3.0p2, protocol versions 1.5/2.0.' ( SNAP-20010108 )
remote:'SSH Secure Shell 2.3.0 ....'

I remove in files:
- clientloop.c
- session.c
- ssh.c
'@openssh.com' in lines about agent authentication.

after this sshd2/1 ( from ssh.com ) on remote machine create unix domain socket, but work 
fine only if I connect to sshd1 ( protocol version 1.5 ).

If connection is to sshd2 ( protocol version 2 ) command 'ssh-add2 -l' ( list auth keys ) 
from ssh.com report this:
ssh_agent_received_packet: packet number 2 (version response from 1.x agent)
and 'forwarding of the authentication agent connection' don`t work !

What can I do ?
How to check packets response from OpenSSH agent to SSH server ?
File 'authfd.h' has 'private OpenSSH extensions for SSH2' . Is this wrong ?