OpenSSH <--> SSH2 interoperability

[Kirk Hilliard <kirk@debian.org>]

sshd(8) tells of a -V switch

  -V client_protocol_id
          SSH2 compatibility mode.  When this options is specified
          sshd assumes the client has sent the given version string
          and skips the Protocol Version Identification Exchange.

but I can't find this further documented either in the man page or in
/usr/doc/ssh/.  Does anyone here know about this, and what format
"client_protocol_id" is supposed to be?  All formats I try earn me a
"Protocol mismatch." error.


My specific situation is that I have someone who tried to connect to
my sshd (OpenSSH-1.2.3, from ssh_1.2.3-2) with an ssh version 2.0.9
and was told:
  Disconnected; protocol version not supported.
Has anyone here run experienced this?


I thought that various versions of ssh played well together even with
OpenSSH's default configuration, but the name "SSH2 compatibility mode"
suggests otherwise.

Kirk Hilliard