By default, Domain Time II will use any available port as the source port when sending requests. The
first free ephemeral port is assigned by the operating system at the time of the request. You may, however,
force Domain Time II to use a specific port instead.
On version 5.x and later, you may change the setting on the Network property page of the Domain Time applet.
On earlier versions, you must use the registry to make the change.
The following registry entries control the
source port used for Domain Time II, NTP/SNTP, and TIME/ITP on
Server,
Full Client,
and Thin Client.
- Send Port DT2
REG_DWORD
Default: 0 (or not present)
- Send Port NTP
REG_DWORD
Default: 0 (or not present)
- Send Port TIME
REG_DWORD
Default: 0 (or not present)
By default, these entries are not present or set to zero. When the value is not present or zero,
the system will use any available port. When the value is any other number (1 to 65535) the
system will try to use the port you specify. Changes take effect immediately.
Note that you cannot specify a port that is already in use by Domain Time or another process. For
example, Domain Time II is always listening on port 9909, so you cannot also send requests on port
9909. Likewise, any machine running a web server is listening on port 80, so you cannot send requests
from port 80.
If Domain Time cannot obtain ownership of the port you specify, it will try to continue operating using the
first free port provided by the operating system. If Domain Time can obtain ownership, it will use
the port you specify for the duration of the request, and then release it for use by other programs
or the next Domain Time request. However, you may have unexpected results. Always verify the port you are specifying is free.