Hello,

I was not able to connect to ExtremeNetworks switches using Zabbix SSH agent item. It was working with the classic openssh client. We got this on the zabbix_server log :

error: Cannot establish SSH session:

We've narrow it down to a problem with the libssh2 banner. We adapted the "ssh2.c" example program from the libssh2 project to take a banner as an argument (using libssh2_session_banner_set function) Here is the result :

This is not working :

$ ./ssh2 192.168.0.10 admin xxxx SSH-2.0-libssh2_1.7.0_DEV
Failure establishing SSH session

$ ./ssh2 192.168.0.10 admin xxxx SSH-2.0-libssh2_
Failure establishing SSH session

But this is working :

$ ./ssh2 192.168.0.10 admin xxxx SSH-2.0-libssh2
Fingerprint: F9 72 8F 75 1E 2B F8 63 E9 19 77 B6 6C 50 C1 13 B4 80 77 5D

$ ./ssh2 192.168.0.10 admin xxxx SSH-2.0-libssh42
Fingerprint: F9 72 8F 75 1E 2B F8 63 E9 19 77 B6 6C 50 C1 13 B4 80 77 5D

$ ./ssh2 192.168.0.10 admin xxxx SSH-2.0-libssh
Fingerprint: F9 72 8F 75 1E 2B F8 63 E9 19 77 B6 6C 50 C1 13 B4 80 77 5D

$ ./ssh2 192.168.0.10 admin xxxx SSH-2.0-zabbix
Fingerprint: F9 72 8F 75 1E 2B F8 63 E9 19 77 B6 6C 50 C1 13 B4 80 77 5D

I've created https://support.zabbix.com/browse/ZBX-11130 before being able to a very recent version of ExtremeXOS. The update made libssh2 working.

I think that being able to configure the ssh banner could be a nice thing to have to workaround those kind of problem.