Ребята, выставил loglevel=DEBUG3 и смотрю лог:
Oct 17 18:29:24 localhost sshd[14217]: debug3: fd 5 is not O_NONBLOCK
Oct 17 18:29:24 localhost sshd[14217]: debug1: Forked child 18244.
Oct 17 18:29:24 localhost sshd[14217]: debug3: send_rexec_state: entering fd = 8 config len 778
Oct 17 18:29:24 localhost sshd[14217]: debug3: ssh_msg_send: type 0
Oct 17 18:29:24 localhost sshd[14217]: debug3: send_rexec_state: done
Oct 17 18:29:24 localhost sshd[18244]: debug3: oom_adjust_restore
Oct 17 18:29:24 localhost sshd[18244]: Set /proc/self/oom_score_adj to 0
Oct 17 18:29:24 localhost sshd[18244]: debug1: rexec start in 5 out 5 newsock 5 pipe 7 sock 8
Oct 17 18:29:24 localhost sshd[18244]: debug1: inetd sockets after dupping: 3, 3
Oct 17 18:29:24 localhost sshd[18244]: Connection from 10.222.107.208 port 47590 on 172.21.14.29 port 24446
Oct 17 18:29:24 localhost sshd[18244]: debug1: Client protocol version 2.0; client software version OpenSSH_7.4
Oct 17 18:29:24 localhost sshd[18244]: debug1: match: OpenSSH_7.4 pat OpenSSH* compat 0x04000000
Oct 17 18:29:24 localhost sshd[18244]: debug1: Enabling compatibility mode for protocol 2.0
Oct 17 18:29:24 localhost sshd[18244]: debug1: Local version string SSH-2.0-OpenSSH_6.6.1
Oct 17 18:29:24 localhost sshd[18244]: debug2: fd 3 setting O_NONBLOCK
Oct 17 18:29:24 localhost sshd[18244]: debug3: ssh_sandbox_init: preparing rlimit sandbox
Oct 17 18:29:24 localhost sshd[18244]: debug2: Network child is on pid 18245
Oct 17 18:29:24 localhost sshd[18244]: debug3: preauth child monitor started
Oct 17 18:29:24 localhost sshd[18244]: debug1: SELinux support disabled [preauth]
Oct 17 18:29:24 localhost sshd[18244]: debug3: privsep user:group 74:74 [preauth]
Oct 17 18:29:24 localhost sshd[18244]: debug1: permanently_set_uid: 74/74 [preauth]
Oct 17 18:29:24 localhost sshd[18244]: debug1: list_hostkey_types: ssh-rsa,ecdsa-sha2-nistp256,ssh-ed25519 [preauth]
Oct 17 18:29:24 localhost sshd[18244]: debug1: SSH2_MSG_KEXINIT sent [preauth]
сетевики клянутся, что дали доступ. (по факту телнет проходит)
Проблема с cipher-ами ? как понять в чем дело ?