Time synchronisation circuit

Time synchronization involves the following subsystems:

1. The NTP master time server: Our master NTP server gathers time from external NTP servers, and then serves it out to the other internal machines. It runs on ltnb0
2. The Samba server runs on the same machine as the master NTP server, and sends time to the Windows clients as soon as the user logs in. This is done in response to an explicit request by those clients, caused by the following line in /home/samab/netlogon/Win95:
   NET TIME \\POLLUX /SET /Y 2>NUL >NUL
   and a similar line for NT.
3. The other unix machines (NTP slaves) synchronize themselves from our master server, using the NTP protocol, rather than contacting the external servers directly.

Needed cisco ports

TCP and UDP ports 123 from & to ltnb0, in order to allow the master NTP time server to connect to its time sources outside.