Note: Settings on this page do not change the roles of other machines; they only affect how this master treats them.

Two different classes of Domain Time II slaves are displayed here - slaves that are part of the same Windows domain as the master server (known as Domain Slaves), and slaves that are not part of the master's domain (known as Foreign Slaves).

The Domain Time II Control Panel Applet - Slave Lists Tab

Domain Slaves

Domain Slaves (by default, all DCs running Domain Time II Server) receive and act upon these control messages sent from the master server:

1. Level-1 cascade signals - triggers the slave to update its own time from the master, and then send a Level-2 cascade signal to its own clients to trigger them to update their time from the slave.
2. Timing Settings - the clock timing parameters set for it on the master's Slave Timings page.
3. Promotion Information - A copy of the master's server, source and timing parameters, to be used automatically if the slave is ever promoted to replace the existing master (in the event of a PDC crash, for example).

See Cascading Time Hierarchy for more information on these items.

Use Automatic Settings (Recommended)
Instructs Domain Time II Server to automatically maintain its own list of domain slaves.

When this box is checked, the master server will automatically identify slaves in its domain. We recommended that you allow the master to run with the Use Automatic Settings box checked; this assures that the master/slave relationships operate correctly, and that the master will identify new slaves as they appear.

The Domain Slaves list box show the machines that are currently slaves. The Available Servers list box shows any other Domain Time II servers in the domain. You can move servers from one list to the other using the arrow keys or by double-clicking the server name.

Although Use Automatic Settings is the correct choice for most situations, there may occasionally be times when you will want to adjust the server's list of domain slaves manually. For example, if you have a slave machine that no longer exists or is offline for a long period of time, the master server logs will include connection error messages each time the master sends a Level-1 cascade signal to the slaves. Moving that server to the Available Servers list will stop the warning messages.

Note that moving an independent server from the list of Available Servers into the Domain Slaves list will not turn an independent server into a slave. Independent servers always ignore Level-1 cascade signals; this configuration will not produce warning messages on either the independent server or its master.

When the Pick from List box is checked, any new slave servers created will not be added to the Domain Slaves list automatically; they will show up in the Available Servers column instead and won't receive Level-1 cascade signals until you manually move them to the other column.

Foreign Slaves

Foreign Slaves receive and act upon Level-1 cascade signals, but otherwise behave according to their server role. This allows you to combine multiple domains into a single time hierarchy, letting one master synchronize all the others.

The Foreign Slaves section of the Slave Settings tab on the overall master shows those domains that have registered themselves with the master as being foreign slaves.

Important Concepts:

---

If a domain name is listed in the Foreign Slaves listbox, the entry actually refers to the Domain Time II Server running on the current PDC (as master) of that domain.

The advantage of referring to the domain name instead of the actual machine name is that the overall Domain Time II Server master is always able to connect to the current PDC (even if some other machine is eventually promoted to the PDC role in that domain).

If a machine name or IP address is listed, the entry refers to an independent server that has registered itself with this server as a foreign slave.

---

Any master or independent server in another domain can become a foreign slave of this domain if you check its Set this machine to be a slave of a foreign master checkbox (see Time Sources). That machine will then register itself as a foreign slave of this domain, and begin to receive Level-1 cascade signals as if it were a normal Domain Slave.

For example, say your company has two domains: HEAD_OFFICE and REMOTE_OFFICE. Installing Domain Time II on the PDC of each domain results in two master Servers, operating independently of each other. This can be inconvenient, particularly if you need to open firewall access for each server and configure each server individually.

By setting the REMOTE_OFFICE domain to be a foreign slave of HEAD_OFFICE, you avoid these problems. The REMOTE_OFFICE master will now automatically get its time from the HEAD_OFFICE master just as if it were a slave in the HEAD_OFFICE domain. The REMOTE_OFFICE master will continue to act as the master server in its own REMOTE_OFFICE domain, serving time exactly as before to its own slaves and clients (or even its own foreign slaves).

Adding and Removing Foreign Slaves
Although the process of adding Foreign Slaves is usually handled automatically, there may be occasions when you will need to add or remove a foreign slave from the list manually. For example, if you have a foreign slave that no longer exists, the master server logs will include warning messages each time the Master sends a Level-1 cascade signal to the slave. You can remove the obsolete domain by highlighting its name and clicking Remove.

The Domain Time II Control Panel Applet - Adding/Removing Foreign Slaves

Also, you may find that your particular domain browsing or network configuration prevents foreign slaves from registering themselves with the overall master correctly. In that event, you can add the slave manually by specifying the foreign domain name, DNS Name, IP address, or even the NETBIOS name.

Note that adding a Foreign Slave to the list manually will not turn a remote machine into a slave. You must also check the Set this machine to be a slave of a foreign master checkbox on the other machine.

• Cascading Time Hierarchy
• Selecting a Server Role
• Implementation Guidelines
• Using Domain Time II across routers and firewalls

 Proceed to the Registry Settings page

 Back to the Client Settings page