Settings on this page control how Domain Time listens and sends traffic to the network.
CAUTION: The default settings on this page are usually correct for most applications.
Only make changes if you are sure you need them and you fully understand the effects of the change.
These settings are unique to each machine, and therefore cannot be saved or imported using the Import/Export utilities.
Use these settings to tell Domain Time which IP addresses to use when listening for incoming network traffic and whether to join multicast groups.
IMPORTANT: Keep in mind that there can only be one network service listening on any one network port on any one IP address.
Domain Time will attempt to control all the enabled time protocol ports on the selected IP address(es) when the service starts.
You may select which protocols are enabled on the Serve the Time property page.
IPv6 requires operating system support, which is present by default in Vista or above, but must be specifically
installed/enabled on XP. Domain Time will function in IPv4-only mode if IPv6 is not present. If both
are present, you may choose which to use, or let the system figure it out.
Domain Time assumes your TCP/IP and Windows networks are configured properly, i.e. name resolution is functioning,
rules are in place to permit traffic through switches, routers, and firewalls, any Active Directory/Domain structure is functioning correctly, etc.
Join DT2/NTP IPv4 multicast groups
Join DT2/NTP IPv6 multicast groups
These checkboxes control whether Domain Time will join multicast groups to listen for either NTP or DT2 protocol multicast traffic.
Multicasts may include not only time sync information, but client discovery packets from Manager and Audit Server. You should not disable
this function unless you have a compelling reason to do so. Note this setting only applies to joining groups.
You can control the multicast address and whether multicasts are sent on the Broadcasts and Multicasts property page.
Initiate rebind and resync if IP address changes
If this checkbox is checked, Domain Time will rebind interfaces if it notices that an IP address has been changed/added while the service is running.
Use this option if your machine is likely to have its list of IP addresses change during operation.
Enumerate multicast interfaces during IPv4/IPv6 bind
Instructs Domain Time to include all addresses capable of multicast when it binds to the network interfaces. Check this box if the machine is multihomed.
Reply to multicasts using incoming interface if possible
Use this option to reduce unnecessary multicast traffic. When checked, and if the machine is multihomed and listening using a specified list of IP addresses (see below), Domain Time will attempt to reply to multicasts (such as PTP messages)
over the same interface on which they were received. If unchecked, Domain Time will attempt to reply on all known interfaces. This feature has no effect if the Listen on all IP addresses available option is selected.
Check this box only if the machine is multihomed and you have addresses listed in the Listen only on these addresses: box.
Listen on all IP addresses available
Listen only on these addresses:
By default, Domain Time attempts to listen for network traffic on all available interfaces. However, you can restrict this to specific IP addresses and/or address ranges if necessary.
IMPORTANT: Be sure to include the hostname
localhost in your list of IP addresses to ensure
that foreground Domain Time processes (such as the Domain Time applet) can continue to talk to the Domain Time service correctly.
As of v5.2.b.20190701, you may enter comments in the specified listen-only list. Comments are defined as text following a hashtag or semicolon.
(If the hashtag or semicolon is the first character, the entire line is considered a comment.) For example, you may use this syntax:
; These are our subnets:
172.16.13.0/24 # main network
192.168.33.0/24 # internal network
Comments in the list (other than commenting out an entire line) are not backward-compatible with previous
versions of Domain Time, so don't use them in templates until all of your machines have been upgraded.
Use this section to specify a fixed source port for time protocol traffic.
These settings should be left blank unless you have a specific requirement to send traffic from a specific source port.
If you do need to set this port, you must not select the same port that is used for listening.
Note: Take care in assigning this port to avoid conflicts with any other port that may be used by any other service.
In particular, you should not assign a port number in the ranges Windows will use for ephemeral source port assignment.