ssh can not connect to AIX 5

[Volker Borowski]

Hi,

I try to connect from RedHat 8.0 to AIX5.1 with ssh 3.41.
The session just hangs at the point, where it initiates the connect.

ssh -V
OpenSSH_3.4p1, SSH protocols 1.5/2.0, OpenSSL 0x0090602f

ssh -vvv user@host

OpenSSH_3.4p1, SSH protocols 1.5/2.0, OpenSSL 0x0090602f
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Rhosts Authentication disabled, originating port will not be trusted.
debug1: ssh_connect: needpriv 0
debug1: Connecting to host [] port 22.

While in this state, the client show the connection in "netstat -an" in state SYN_SENT.
The server (sshd) does not show a connection at all.

Ping ist workinging in both directions.
ssh from AIX to Linux works ok.
When starting a telnetd on AIX, a telnet connection from the same client is no problem.

-> This suggests that from the TCP/IP-side all is ok.

Am I missing something on the configuration side ?

Thanks
Volker

[Steven E. Protter · Accepted solution]

Make sure any firewalls are shut down or not blocking port 22 on the AIX box.

On linux, experiment with.

service iptables stop

or

service ipchains stop

depending on your firewall.

Report back.

SEP

[U.SivaKumar_2]

Hi,

please do ssh again from linux to AIX and paste the tail output of /var/log/messages.

Have you checked what protocol verison is supported by sshd in AIX ?

you RH 8.0 ssh client may be trying to use protocol version 2 by default which may not be supported by MIX sshd.


Then try these combinations from linux

#ssh -1 user@AIX

if you are able to connect then the MIX sshd supports only protocol version 1.

also

#ssh -2 user@AIX

regards,

U.SivaKumar

[U.SivaKumar_2]

Hi,

please do ssh again from linux to AIX and paste the tail output of /var/log/messages.

Have you checked what protocol verison is supported by sshd in AIX ?

you RH 8.0 ssh client may be trying to use protocol version 2 by default which may not be supported by MIX sshd.


Then try these combinations from linux

#ssh -1 user@AIX

if you are able to connect then the MIX sshd supports only protocol version 1.

also

#ssh -2 user@AIX

regards,

U.SivaKumar

[U.SivaKumar_2]

Hi,

please do ssh again from linux to AIX and paste the tail output of /var/log/messages.

Have you checked what protocol verison is supported by sshd in AIX ?

you RH 8.0 ssh client may be trying to use protocol version 2 by default which may not be supported by MIX sshd.


Then try these combinations from linux

#ssh -1 user@AIX

if you are able to connect then the MIX sshd supports only protocol version 1.

also

#ssh -2 user@AIX

regards,

U.SivaKumar

[Volker Borowski]

Good Morning,

additional input.
Unfortunatly, I only have acces to the linux box. The AIX box does not belong to me, so collectiong data is a bit more complicate.

Steven: As far as it looks now, I also suspect there is some filtering in place (which does not belong to me :-), but as far as the other side is concerned I am told there is none ...

Siva: Either connects with -1 or -2 result in the same output, I already posted. /var/log/messages (on linux) does not get any additional entries for any of the above commands.

For more information I have to wait for a date with the admin on the remote side.

telnet remotehost 22

does not return a message while

telnet localhost 22
returns

[root@myhost root]# telnet localhost 22
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
SSH-1.99-OpenSSH_3.4p1
Protocol mismatch.
Connection closed by foreign host.

So since the other try does not get any response in any way, I'd tend to go with Stevens suggestion. I'll keep you informed.

Thanks so far
Volker