After changing the ip address(temperorily) ssh to that server is very slow(exactly 25 sec).But from this new ip i can ssh to other servers without any delay problem.
debug1: match: Sun_SSH_1.1.1 pat Sun_SSH_1.1.1*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-Sun_SSH_1.1.1
debug1: Failed to acquire GSS-API credentials for any mechanisms (No credentials were supplied, or the credentials were unavailable or inacces
mech_dh: Invalid or unknown error
)
debug1: SSH2_MSG_KEXINIT sent
takes 25 secs
debug1: SSH2_MSG_KEXINIT received
SSH2_MSG_KEXINIT (key exchange initialization) is the first part of the SSH key exchange, as described here (space added because I am not allowed to post links):
http ://tools.ietf.org/html/rfc4253#section-7.1
Having said that, are you sure this isn't a DNS problem? Delays like this can be caused by the server trying to do a DNS lookup, but getting a timeout. Often this is for logging purposes, so you may be able to prevent it by telling the server to log IP addresses instead of DNS names.
Think so, I suppose that it can be suppressed by disabling reverse DNS lookup for sshd daemon.
You can try add line "UseDNS no" into /etc/ssh/sshd_config file.
If you would like to switch off using DNS lookup for sshd at all you should probably add appropriate option to ssh SMF manifest and then refresh service configuration.