'ssh -f' option, interoperability with ssh v2.3.0

[Markus Friedl]

On Thu, Aug 31, 2000 at 08:50:00AM +0300, Marko Asplund wrote:
> i'm trying to use the ssh command's -f option with OpenSSH v2.1.1p4 on
> linux (RedHat v6.2). this option doesn't seem to be working properly on my
> system - the specified is run succesfully but it isn't put to the
> background. is this a known problem?
> 
> also, OpenSSH doesn't seem to interoperate with SSH Communications
> Security's ssh v2.3.0 (apparently because of different opinions about HMAC
> sizes). this can be fixed in the (ssh v2.3.0) configuration files by
> specifying:
> 
> 	MACs		hmac-md5
> 
> but is there any work being done for fixing this this problem in OpenSSH's
> part?

yes. OpenSSH and ssh.com-2.3.0 disagree on how hmac-sha1 should be
implemented. OpenSSH-2.2.0 detects ssh.com-2.3.0 and uses their
scheme. the next release implementes '-f' for protocol 2, too.