Slow login times in Ubuntu 13.10 (not just SSH)

I recently setup a new install of Ubuntu 13.10 for a server and found that a lot of my login times were slow when remotely logging in (and not just via SSH). The culprit turned out to the the /etc/nsswitch.conf file:

This line:
hosts: files mdns4_minimal [NOTFOUND=return] dns mdns 4 mdns

Should be changed to this line:
hosts: files dns

... to resolve the issue

Resolving slow SSH login times

At work, like most other organizations, we have a Linux server that we access via SSH. However, lately, I've found my use of it skyrocketing in order to test software, and log-ins and file copying have been very slow. In my efforts to find out why, I found out that sshd has in its configuration file a setting called 'UseDNS'. The default is 'yes', so even if this setting is commented out, it will try to perform reverse DNS lookups on the IP addresses of users logging in. This would be a bad thing for us, especially since we have this box locked down and unable to contact any DNS servers. After disabling DNS lookups, my login and file copy time dropped to near 0. I hope this helps somebody.

*EDIT:* I've also encountered this problem on the BeagleBone Black boards which I've recently acquired for use in a project.