Hi Muhammad,
I think this is an issue specific to SSHD--not much of anything to do with BIG-IP. You could try searching the web for this error message. There are quite a few forum posts with troubleshooting suggestions. You could try running a new instance of sshd with debug enabled:
http://mrraph.net/WordPress/?p=16
/usr/sbin/sshd -d -p 2200
and then connect on port 2200. Or you could change the LogLevel in /config/ssh/sshd_config to debug, reload the config using kill -HUP `pidof sshd`and then retest.
Here are some related links:
http://archive.netbsd.se/?ml=openssh-unix-dev&a=2007-10&t=5430083
I suspect you're hitting the MaxStartups unauthenticated connection
limit. It default is 10, try bumping it on the servers to, say, 30 or 40.
http://lists.mindrot.org/pipermail/openssh-unix-dev/2008-February/026176.html
> Hi,
>
> I'm getting this error when I ssh to the servers.
> ssh_exchange_identification: Connection closed by remote host
>
> I added /etc/hosts.allow and it actually worked once and if I tried again I get the same error.
You did not mention whether you added by name or by IP.
Every time I've seen this error it has been a DNS problem. And I only
see this on systems that are in hosts.allow by name.
Aaron