SSH connection stuck in 'Local version string'

I remember facing the same issue when using UseDNS yes in my sshd config, try setting it to no and hopefully it'll resolve your problem

if your ISP gives IPs without rDNS this usually happens

how to know if your IP has a reverse DNS record? visit www.whatismyip.com or similar and take the IP then run host 1.1.1.1 where 1.1.1.1 is your IP and see if it gives a reply back, if it doesn't like when you host 11.11.11.11 then your ISP doesn't set rDNS records

bashar@bashar-ThinkPad-W520:~$ host 1.1.1.1
1.1.1.1.in-addr.arpa domain name pointer one.one.one.one.

bashar@bashar-ThinkPad-W520:~$ host 11.11.11.11
Host 11.11.11.11.in-addr.arpa. not found: 3(NXDOMAIN)

Additionally, you may want to look at GSSAPIAuthentication no or test it by adding -u0 to your ssh command

I've stuck with the same problem and I've worked around with this configuration:

The key was setting Guest IP as 0.0.0.0

HTH