Limitations Creating DHCP Reservations

• Microsoft Windows NT Server version 4.0
• Microsoft Windows NT Server, Enterprise Edition version 4.0

SUMMARY

DHCP manager will allow certain DHCP reservations outside the DHCP scope range but will deny if they are outside the subnet range. Several rules must apply when creating reservations.

MORE INFORMATION

The DHCP server must service the subnet where the reservation is being created.

These three rules will guide you in creating reservations:

1. You may create a reservation within any scope range.



2. You may create a reservation within a subnet range even if the reservation falls outside the actual scope Start and End addresses for that subnet.



3. You cannot create reservations outside the subnet range of any of your existing scopes.

• Let's say you have a standard Class C subnet for 192.168.1.0 with mask 255.255.255.0.



• You can create a scope for the first half of the subnet so the scope has a starting address of 192.168.1.1 and an ending address of 192.168.1.150.



• You can now create a reservation for the address 192.168.1.25. (Rule 1)



• You can also create a reservation that lies outside the scope but still within the subnet range; for example, reserve 192.168.1.200. (Rule 2)



• You cannot create a reservation for the address 192.168.2.4, which lies outside the subnet of any existing scope. (Rule 3)

Additional query words: kbDSupport

Keywords          : kbnetwork 
Version           : WinNT:4.0
Platform          : winnt 
Issue type        : kbinfo 

Last Reviewed: February 24, 1999