Subnet prioritization for IP address allocation from a DHCP server

1. A method for handling Dynamic Host Configuration Protocol (DHCP) at a first DHCP server, said method comprising steps of:

receiving, via a user interface at the first DHCP server, a priority for each of a plurality of subnets;

assigning the priority to each of the plurality of subnets;

receiving a DHCP Discover message from a client;

in response to receipt of a DHCP Discover message from a client, selecting a subnet having a highest priority from said plurality of subnets;

selecting an Internet Protocol (IP) address from said selected subnet having a highest priority; and

transmitting a DHCP Offer message to said client, offering said selected IP address.

2. The method of claim 1 , wherein said assigning a priority comprises receiving input from an operator.

3. The method of claim 1 , wherein said assigning a priority comprises receiving input from a configuration file.

4. The method of claim 1 , further comprising steps of identifying at said first DHCP server, fully used subnets; partially used subnets; and unused subnets;

first migrating unused subnets from said first DHCP server to a second DHCP server;

migrating fully used subnets from said first DHCP server to said second DHCP server; and

then migrating partially used subnets from said first DHCP server to said second DHCP server.

5. The method of claim 1 , further comprising the steps of:

in response to receipt of a DHCP Discover message from a client, determining a previously used IP address for said client; and

determining that IP address is no longer available prior to selecting a subnet.

6. The method of claim 1 , further comprising the steps of: determining an IP pool based on an address of the DHCP Discovery message; and determining subnets associated with the IP pool.

7. The method of claim 1 , wherein the step of receiving, at the first DHCP server, a priority for each of a plurality of subnets, further comprises: receiving a configuration file.

8. A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform the steps of:

receiving, via a user interface at the first DHCP server, a priority for each of a plurality of subnets;

assigning the priority to each of the plurality of subnets;

receiving a DHCP Discover message from a client;

selecting a subnet having a highest priority from said plurality of subnets;

selecting an Internet Protocol (IP) address from said selected subnet having a highest priority; and

transmitting a DHCP Offer message to said client, offering said selected IP address.

9. The program storage device of claim 8 , further comprising steps of identifying at said first DHCP server, fully used subnets; partially used subnets; and unused subnets;

first migrating unused subnets from said first DHCP server to a second DHCP server;

migrating fully used subnets from said first DHCP server to said second DHCP server; and

then migrating partially used subnets from said first DHCP server to said second DHCP server.

10. The program storage device of claim 8 , wherein said assigning a priority comprises receiving input from an operator.

11. The program storage device of claim 8 , wherein said assigning a priority comprises receiving input from a configuration file.

12. A DHCP server, comprising:

a processor; and

a memory communicatively connected to the processor, the memory having stored thereon instructions which, when executed by the processor, cause the processor to:

receive, via a user interface at the first DHCP server, a priority for each of a plurality of subnets;

assign the priority to each of the plurality of subnets;

receive a DHCP Discover message from a client;

select a subnet having a highest priority from said plurality of subnets;

select an Internet Protocol (IP) address from said selected subnet having a highest priority; and

transmit a DHCP Offer message to said client, offering said selected IP address.

13. The DHCP server of claim 12 , wherein said assigning a priority comprises receiving input from an operator.

14. The DHCP server of claim 12 , wherein said assigning a priority comprises receiving input from a configuration file.

15. The DHCP server of claim 12 , wherein the instructions further cause the processor to identify at said first DHCP server, fully used subnets; partially used subnets; and unused subnets;

first migrate unused subnets from said first DHCP server to a second DHCP server;

migrate fully used subnets from said first DHCP server to said second DHCP server; and

then migrate partially used subnets from said first DHCP server to said second DHCP server.