JP2000278322A - Dynamic ip address allocating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the retrieval time of various protocol tables in the form of hash table. SOLUTION: This device is provided with an IP address table 20 obtained by adding hash function values to IP addresses within an allocation enable range and an equal has function value table 23 storing the number of allocated IP addresses for each hash function value and when the request of an IP address is received from a node 1, an allocation control part 12 responds to that request by retrieving the equal has function value table 23, selecting one hash function value having the minimum number of allocated IP addresses, next selecting one empty IP address having this selected hash function value, determining it as an allocation IP address and sending it to the request source node 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IP received from a DHCP (Dynamic Host Configuration Protocol) client via a network.
(Internet Protocol) IP address dynamic allocation apparatus for dynamically allocating one free IP address in response to an address request, and more particularly to an IP address dynamic allocation apparatus capable of shortening the search time of various protocol tables based on a hash table About.

[0002]

2. Description of the Related Art Conventionally, in this type of IP address dynamic allocating apparatus, an allocation control section has a DHCP function as a node.
When a request for assigning an IP address is received from a client, at this point in time, the IP addresses having the smallest numerical value among the free IP addresses are sequentially assigned.

[0003] That is, when receiving an IP address assignment request, the IP address assignment control unit, for example, starts from the IP address listed in ascending order as shown in the IP address table 20 of FIG. Irrespective of the IP address, the IP address with the lowest available number is selected and assigned.

[0004]

The above-described conventional IP address dynamic allocation apparatus has a problem that a search time of a protocol table of each node increases.

[0005] The reason is that various protocol tables used when each node communicates with other nodes, for example, IP
In a routing table, an ARP (address resolution protocol) table, an ATM (asynchronous transfer mode) ARP table, etc., an IP address is stored in a hash table format for the purpose of high-speed search. This is because, as a result of repeating the empty state due to the cancellation, the distribution of the formed hash table is biased.

An object of the present invention is to solve the above problems,
An object of the present invention is to provide an IP address dynamic assignment device capable of shortening a search time in various protocol tables in a hash table format.

[0007]

According to the present invention, an apparatus for dynamically allocating an IP address according to the present invention comprises:
When an address assignment request is received, the assigned I
An IP address assignment control means is provided for selecting and assigning, from the free IP addresses, one IP address that makes the hash table distribution substantially the same as the P address. Further, as a specific means, there is provided an identical hash function value table for storing the number of IP addresses assigned for each predetermined hash function value. The IP address assignment control unit, upon receiving the IP address assignment request,
A hash function value with the smallest number of assigned IP addresses is read from the same hash function value table, and one free IP address having the read hash function value is selected.

[0008] With this configuration, the assigned IP address is almost equally assigned to each hash function value.
The distribution of the P addresses is maintained almost uniformly.

[0009] One of the specific configurations is an IP address management table that stores predetermined hash function value information and information of either assigned or empty for each IP address within an assignable range,
A DHCP protocol communication unit that communicates with a DHCP client via a network, and when an IP address assignment request is received via the DHCP protocol communication unit, the IP address is added to the assigned IP address from the IP address management table. And IP address assignment control means for selecting and assigning one IP address that makes the hash table distribution almost the same from available IP addresses.

[0010] The IP address management table includes an assigned IP address table listing the assigned IP addresses to which the respective hash function values are assigned, and a free IP address listing the available IP addresses to which the respective hash function values are assigned. And an identical hash function value table that stores the number of assigned IP addresses for each predetermined hash function value.

[0011]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a functional block diagram showing an embodiment of the present invention.

The IP address dynamic assignment device 3 shown in FIG. 1 receives an IP address assignment request via the network 2 from the node 1 which is a DHCP client.

The IP address dynamic assignment device 3
It is assumed that the configuration is made up of an address management table 10, a DHCP protocol communication unit 11, and an IP address assignment control unit (hereinafter abbreviated as an assignment control unit) 12.

An IP address management table 10 stores an IP address table 20 for storing information on whether the address is a free address or an assigned address according to each of the IP addresses in an assignable range, and a number of assigned IP addresses according to a value of a hash function. The same hash function value table 23 to be stored is provided. The number of assigned IP addresses for which the hash function has the same value,
Here, it is called “the number of hash equivalent IP addresses”.

The DHCP protocol communication unit 11 has a DHCP protocol.
Protocol communication based on the protocol is performed with the node 1 via the network 2. Assignment control unit 12
When a new IP address allocation request is made, the IP address management table 10 is searched, and based on the number of hash equivalent IP addresses, one empty IP address is set so that the distribution of the hash table is optimally uniform. Select and assign an address.

[0017]

Next, referring to FIG. 2 and FIG. 1, the IP of FIG.
One embodiment for the address management table 10 will be described. It is assumed that the IP address table 20 of the IP address management table 10 is divided into an assigned IP address table 21 and a free IP address table 22.

The IP address 192.0.0.1-
192.0.0.16 is an assignable range, and as shown, the assigned IP address table 2
1 has an IP address 192.0.0.1-3, 7-9,
12, 15 and the free IP address table 22 has IP addresses 192.0.0.4 to 6, 10, 11, 1
3, 14, and 16 are stored.

It is assumed that the hash function is “the remaining number obtained by dividing the least significant byte (1 to 16) of the IP address by the numerical value 4”, and the IP address table 10 or the two assigned and free IP addresses Table 2
It is assumed that the IP address is attached to the IP address stored in each of the IP addresses 1 and 22.

The same hash function value table 23 is created from the assigned IP address table 21. That is, the same hash function value table 23 stores, for each hash function value, the number of assigned IP addresses having the same hash function value, that is, the above-mentioned number of hash equivalent IP addresses. Therefore, in the illustrated example, the assigned IP address numbers 2, 2, 1, and 3 are stored in the hash function values 0, 1, 2, and 3, respectively.

Next, the main operation procedure of the IP address assignment control section (assignment control section) 12 in FIG. 1 will be described with reference to FIG. 3 and FIG. 1 and FIG.

When the assignment control unit 12 receives an IP address request from the DHCP client node 1 via the network 2 and the DHCP protocol communication unit 11 (step S1), the same hash function value table 23 of the IP address management table 10 And investigates the number of assigned IP addresses (step S2).

As a result of the investigation, in the table 23, the number of assigned IP addresses, which is “the number of hash equivalent IP addresses”, is different from the numerical values 2, 2, 1, and 3 (N in step S3).
O), the assignment control unit 12 selects the hash function value of the assigned number of IP addresses “1” which is the minimum value (step S4), and that one hash function value “2” is selected (step S5). NO) is confirmed.

Next, the allocation control unit 12 searches the free IP address table 22 for a free IP address having the selected hash function value “2”, and
For example, the minimum IP address 192.0.0.6 is selected (procedure S6). Next, the assignment control unit 12 assigns the selected IP address 192.0.0.6 to the assigned IP address.
By sending the address to the requesting node 1 via the DHCP protocol communication unit 11 and the network 2 as an address, a response is returned (procedure S7), and the procedure ends.

As a result, the same hash function value table 2
In 3, the "number of hash equivalent IP addresses" becomes the number of assigned IP addresses 2, 2, 2, and 3, and a more uniform state is obtained.

If the above procedure S3 is "YES" and the number of assigned IP addresses in the same hash function value table 23 is all the same, for example, the numerical value "2", the allocation control unit 12 sets the predetermined, for example, the minimum value " 0 is searched for in the free IP address table 22, and a predetermined value, for example, the minimum IP address 192.0.
Select 0.4 (procedure S11) and proceed to the above procedure S7.
Assign selected IP address 192.0.0.4 I
The request is sent to the requesting node 1 via the DHCP protocol communication unit 11 and the network 2 as the P address, and the procedure ends.

If the above step S5 is "YES" and there are a plurality of minimum value assigned IP address numbers, the allocation control unit 12 proceeds to the above step S11, where the hash value having the minimum assigned IP address number is determined. From the function values, a predetermined hash function value, for example, a minimum value “0” is selected to search the free IP address table 22, and a predetermined value, for example, a minimum IP address 192.0.0.4 is selected. To step S7.

Although the predetermined value is set to the minimum value in the above description, the maximum value or the value may be sequentially shifted. As described above, in the above description, the functional blocks and the procedures are illustrated and referred to, but changes by separating and merging the functions or exchanging the procedures are free as long as the above functions are satisfied, and the above description limits the present invention. Not something.

[0029]

As described above, according to the present invention, a search time can be reduced in various protocol tables which are used when a node operating on a network communicates with another node and are implemented in the form of a hash table. There is an effect that can be.

The reason is that the IP address assignment control unit assigns the IP address of the node operating on the network to
This is because the distribution of the hash table is allocated so as to be uniform. Specifically, this is because the assignment control unit selects one free IP address as the newly assigned IP address so as to equalize the “number of hash equivalent IP addresses”.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram illustrating a hash function value object showing a specific example of the table of FIG. 1;

FIG. 3 is a flowchart showing one embodiment of a control unit of the present invention.

[Explanation of symbols]

Reference Signs List 1 node 2 network 3 IP address dynamic assignment device 10 IP address management table 11 DHPC protocol communication unit 12 IP address assignment control unit (assignment control unit) 20 IP address table 21 assigned IP address table 22 free IP address table 23 identical hash Function value table

Claims (6)

[Claims] When receiving a request for assigning an IP address from a DHCP client, an IP address that selects and assigns one IP address that makes the hash table distribution substantially the same as an assigned IP address from free IP addresses in addition to the assigned IP address. An IP address dynamic allocation device, comprising: an allocation control unit. 2. An apparatus according to claim 1, further comprising an identical hash function value table for storing the number of assigned IP addresses for each predetermined hash function value, wherein said IP address assignment control unit receives an IP address assignment request. When
I assigned from the same hash function value table
An IP characterized by reading a hash function value with the smallest number of P addresses and selecting one free IP address having the read hash function value based on a predetermined procedure.
Address dynamic allocation device. 3. An IP address dynamic allocating apparatus which dynamically selects and allocates one of free IP addresses when receiving an IP address allocation request from a DHCP client. An IP address management table that stores hash function value information and information of either assigned or empty, and a DHCP protocol communication unit that communicates with the DHCP client via a network;
When an IP address assignment request is received via the DHCP protocol communication unit, one IP address that makes the hash table distribution almost the same when added to the assigned IP address is used from the IP address management table. IP address assignment control means for selecting and assigning from an IP address.
P address dynamic allocation device. 4. The IP address management table according to claim 3, wherein the IP address management table includes an assigned IP address table listing the assigned IP addresses to which the respective hash function values are assigned, and an empty IP address to which the respective hash function values are assigned.
An IP address dynamic allocation device, comprising: a free IP address table listing addresses. 5. The IP address management table according to claim 3, wherein the IP address management table includes an IP address assigned for each predetermined hash function value.
An IP address dynamic allocating device comprising an identical hash function value table for storing the number of P addresses. 6. The IP address assignment control unit according to claim 5, wherein the IP address assignment control unit reads a hash function value with the smallest number of assigned IP addresses from the same hash function value table when receiving an IP address assignment request,
An IP address dynamic allocation apparatus, wherein one free IP address having a read hash function value is selected based on a predetermined procedure.