Description of problem: After the last update there are no issues with doing 'ssh -C ...' between machines with the same version of openssh. It actually works as well with a client running FC3. But if I will try the same from a client running RH7.3 with openssh-3.1p1-18.73 I see when using '-v' flag: ..... debug1: Remote protocol version 2.0, remote software version OpenSSH_4.2 debug1: match: OpenSSH_4.2 pat OpenSSH* Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_3.1p1 debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received no matching comp found: client zlib server none,zlib debug1: Calling cleanup 0x8063520(0x0) and a connection is dropped. There was no problem in connecting before the last update. There is no difference if a server is x86 or x86_64 machine. Doing the same in the other direction works fine. It is still possible to connect to openssh-4.2p1-1 server if '-C' flag is dropped although I cannot tell if something else will not jump out with other clients. My guess that machnines with RHEL 2.1 will have at least the same issue (but I do not have one to test). Version-Release number of selected component (if applicable): openssh-4.2p1-1 How reproducible: Always
This is known bug in the older ssh clients. You can: 1. Either drop the -C flag from the ssh command line of the older ssh clients (<3.5p1). 2. Or modify the /etc/ssh/sshd_config on the server so it contains "Compression yes" which will disable the delayed compression.