When you reserve a range of ephemeral ports, only processes that specifically request a port in the reserved range can use it.
NOTE: Ephemeral (short-lived) port numbers start at 1024.
To reserve one or more ranges of ephemeral ports:
1. Use Regedt32.exe to navigate to:
2. On the Edit menu, Add Value name ReservedPorts as a REG_MULTI_SZ Data Type.
3. For each range that you wish to add, type a line in the Multi-String Editor dialog, using the FFFF-TTTT syntax, where FFFF is the starting port of the range and TTTT is the ending port of the range. If only one port exists in the range, FFFF and TTTT are identical.
4. Press OK when you have finished adding ranges.
5. Exit the Registry Editor.