If you want any system to connect to you, you need to open a port. You don’t need to do that for outgoing connections (the OS and your router will automatically open ports for the return connection). So if everybody connects to one central system, nobody needs to (explicitly) open any ports (except for the central connection point)
Can’t remember exactly what happened but it involved changing permissions on
/bin
/sbin
and similar. You know for security …In the end I didn’t have permissions to run
chmod
,su
orsudo
Fortunately there is little that can’t be fixed by booting from a live image.