JP3676714B2 - Priority selection name server system and client terminal - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides a mechanism capable of seamless name resolution while simultaneously connecting to a plurality of networks configured by different address systems to which a client terminal can be connected. For example, a client terminal connected to the Internet On the other hand, the present invention relates to a preferential selection name server system and a client terminal that provide a mechanism capable of providing content even in a network independent of the Internet.
[0002]
[Prior art]
The client terminal can set a resolver for each driver connected to the network, and can uniquely specify a plurality of name servers to be accessed with priority. Priorities among drivers cannot be specified.
[0003]
In the conventional form of communicating with only one network, the resolver on the client side of the domain name system automatically accesses the name server designated by the driver connected to the network. Further, the resolver gives up the inquiry when name resolution cannot be performed as a result of inquiring multiple times to all the name servers specified in the driver.
[0004]
[Problems to be solved by the invention]
However, in order to avoid the speed bottleneck of the Internet, try to provide certain contents to some client terminals on a network that is independent of the Internet from a driver different from the Internet connection and has sufficient bandwidth. In this case, the client terminal is simultaneously connected to the two networks via different drivers.
[0005]
At that time, the resolver must always go to the name server that exists in the preferred network first, and if the name server of the preferred network cannot resolve the name, the next priority network It is necessary to automatically go to the name server that exists in.
[0006]
The present invention has been made in view of the above points, and when a client terminal equipped with a plurality of drivers for communicating with a specific network is connected simultaneously with a network configured with different connectable address systems, It is an object of the present invention to provide a preferentially selected name server system and a client terminal that select and prioritize name servers that the client terminal accesses for name resolution.
[0007]
[Means for solving problems]
In order to achieve the above object, a priority selection name server system according to the present invention includes a client terminal having a plurality of drivers for communicating with a predetermined network, and a network configured by different address systems to which the client terminal can be connected. And a means for prioritizing and selecting a name server that the client terminal accesses for name resolution when connected simultaneously.
[0008]
The priority selection name server system of the present invention is provided in a client terminal connected to the Internet via an Internet service provider and connected to a content network independent of the Internet configured by a private address. A driver for designating a name server provided in the Internet service provider, a driver for designating a name server provided in the content network, and an inquiry provided for name resolution via the drivers provided in the client terminal Means for designating the priority order of name servers.
[0009]
The present invention also provides a client terminal having a plurality of drivers for communicating with a predetermined network, a plurality of networks configured with different address systems to which the client terminal can be connected, and each network set in the client terminal. In the system for selecting a name server to be accessed by the client terminal for name resolution, a means for specifying the priority order of the name server to which the client terminal goes for name resolution query, The relationship between the name server to be inquired and the priority order is set for each client terminal individually, the means for accessing a new name resolution request in order from the first priority specified in advance, and the name to be appealed If the name server does not resolve, And a means for not changing the priority specified in advance by an external factor, and a means for ending name resolution when all the specified name servers cannot resolve the name. Is.
[0010]
According to the present invention, in the preferential name server system, a client terminal having means for setting a different IP (Internet Protocol) address for each driver and means for uniquely corresponding to a name server accessed for each driver, The client terminal is configured to set an IP (Internet Protocol) routing table to uniquely associate a network address with a driver, and when the client terminal sends out an IP (Internet Protocol) packet, the IP routing of the client terminal A driver corresponding to the network to be accessed is selected with reference to the table, and means for accessing the target network via the driver is provided.
[0011]
Further, the client terminal of the present invention includes an IP having a means for setting a different IP address for each driver, a plurality of drivers having a means for associating a name server accessed for each driver, and a means for associating a network address with the driver. A routing table, a means for specifying the priority order of the name servers to be accessed, a means for preferentially selecting the name server designated for priority, and a name server with the next priority order automatically when the name server does not resolve the name. And a resolver having means for terminating the name resolution if all the designated name servers cannot resolve the name.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings.
[0013]
(1) Overall System Configuration FIG. 1 is a network configuration diagram showing an embodiment of the present invention. In the figure, an ISP (Internet Service Provider) -A30 and an ISP (Internet Service Provider), each of which includes a client terminal 10 and a client terminal 20 each equipped with two drivers, each having a global IP address (G-IP). : Internet Service Provider) -B 40 and connected to the Internet 100, and at the same time, connected to a network 50 (hereinafter referred to as a content network) independent of the Internet, which is composed of a private IP address (P-IP). The client terminal 10 and the client terminal 20 simultaneously communicate with the Internet 100 and the content network 50 via different drivers.
[0014]
The ISP-A 30 includes a name server 31 and a name server 32 that is a secondary of the name server 31, the ISP-B 40 includes a name server 41 and a name server 42 that is a secondary of the name server 41, and the content network 50 includes a name. A server 51 is installed.
[0015]
That is, client terminals 10 and 20 having a plurality of drivers for communicating with a predetermined network;
A plurality of networks NW (i) (i is a natural number) configured with different address systems to which the client terminals 10 and 20 can be connected, and the content network 50;
Name servers 31, 32, 41, 42, 51 which are name servers NS (i, j) (j is a natural number) existing in each network NW (i) set in the client terminals 10, 20;
In the system for selecting a name server to be accessed by the client terminals 10 and 20 for name resolution,
Means for designating the priority order of the name servers NS (i, j) that the client terminals 10 and 20 go to inquire about name resolution;
A means for setting the relationship between the name server and the priority order for the name resolution inquiry individually for each of the client terminals 10 and 20;
Means for accessing a new name resolution request in order from the first priority specified in advance;
A means for transitioning to a name server whose priority is one lower when the name to be appealed is not resolved by the specified name server;
Means to prevent the priorities specified in advance from being changed by external factors;
A means to terminate name resolution when name resolution fails for all specified name servers;
It is a preferential selection name server system characterized by comprising.
[0016]
In the priority selection name server system, means for setting a different IP address for each driver;
Client terminals 10 and 20 having means for uniquely corresponding name servers to be accessed for each driver,
Means for setting the IP routing table of the client terminals 10 and 20 to uniquely associate the network address with the driver;
When the client terminals 10 and 20 send IP packets, the driver corresponding to the network to be accessed is selected by referring to the IP routing table of the client terminals 10 and 20, and the target network is accessed via the driver. It has the means to do.
[0017]
(2) Name server designation For the client terminal 10, the name server 31 and the name server 32 are designated on one driver side, and the name server 51 is designated on the other driver side. The priority order of the name servers that go to the name resolution inquiry via each driver is the name server 51, the name server 31, and the name server 32.
[0018]
In the client terminal 20, the name server 41 and the name server 42 are designated on one driver side, and the name server 51 is designated on the other driver side. The priority order of the name servers that go to the name resolution inquiry via each driver is the name server 51, the name server 41, and the name server 42.
[0019]
In the middle of the priority order between a plurality of name servers existing in one network, name servers existing in other networks cannot be sandwiched.
[0020]
(3) Function of Client Terminal Next, the function of the client terminal that preferentially selects the name server will be described. FIG. 2 is a block diagram illustrating functions of the client terminal 10.
[0021]
The client terminal 10 has an Ethernet driver 11 and a PPPoE driver 12. Each driver 11, 12 has a function (1) for setting a different IP address for each driver 11, 12. Further, it has a function {circle around (2)} corresponding to the name server accessed for each driver 11, 12. In the client terminal 10, the private IP address assigned from the content network 50 is set in the Ethernet driver 11, and the global IP address assigned from the ISP-A 30 is set in the PPPoE driver 12. Further, the accessing name server 51 is associated with the Ethernet driver 11, and the accessing name servers 31 and 32 are associated with the PPPoE driver 12.
[0022]
The client terminal 10 has a function {circle around (3)} that sets the IP routing table 13 to uniquely associate the network address with the driver.
[0023]
Further, the client terminal 10 has a function {circle over (4)} for setting the DNS (Domain Name System) resolver 14 and designating the priority order of the name servers to be accessed, and designates the priority order in the order of the name servers 51, 31, and 32. I can do it. This priority does not change due to external factors. This function can be set individually for each client terminal.
[0024]
The name server 51 has a function {circle over (5)} for preferentially selecting a name server designated with priority, which is preferentially accessed from the name server 51 whose priority is set to first in response to a new name resolution request. If the name server 31 does not resolve the problem, the function shifts to the name server 31 whose priority is lower by one. Have.
[0025]
A function {circle over (7)} that terminates name resolution when name resolution cannot be performed by accessing all designated name servers.
[0026]
(4) Operation when performing name resolution Next, the operation when the resolver of the client terminal 10 performs name resolution will be described with reference to FIGS. 1, 2, and 3. FIG. FIG. 3 shows an operation when name resolution is performed in a state in which two networks are connected. The priority order of the name servers for name resolution is the order of the name server 51, the name server 31, and the name server 32. Further, it is assumed that the content network 50 is connected via the Ethernet driver 11 and the ISP-A 30 via the PPPoE driver 12.
[0027]
First, when name resolution is necessary, the resolver of the client terminal 10 makes an inquiry to the name server 51 having the priority order 1 designated on the Ethernet driver 11 side. If the domain name or data to be searched exists and the name is resolved, the inquiry is terminated.
[0028]
When the domain name or data to be searched does not exist, or when the resolver times out or receives a network error, the resolver automatically sets the priority specified on the PPPoE driver 12 side to the name server 31 with 2 assigned. Inquire about name resolution. If the domain name or data to be searched exists and the name is resolved, the inquiry is terminated. The inquiry is also terminated when a response is received that there is no domain name or data to be searched. This is because the name server 31 and the name server 32 are name servers of the same network and have a “common view” with respect to the name space, so the same query is not repeated.
[0029]
When the resolver times out or receives a network error, the resolver automatically makes a name resolution inquiry to the name server 32 set to the next priority by the PPPoE driver 12. If the domain name or data to be searched exists and the name is resolved, the inquiry is terminated. The inquiry is also terminated when a response is received that there is no domain name or data to be searched.
[0030]
If the resolver sends a query to all configured name servers, but the resolver times out or receives a network error and no response is received, the timeout value is updated and the same cycle [S] Repeat three times.
[0031]
(5) Realization of seamless content provision with the Internet In the IP routing table of the client terminal 10, the private IP address is transferred to the Ethernet driver 11 and the global IP address is transferred to the PPPoE driver 12. By combining the configuration, the function of the client terminal in (3), and the operation for name resolution in (4), it is possible to provide content seamlessly with the Internet.
[0032]
First, the client terminal goes to name resolution queries in order from the name server with the highest priority for name resolution. The client terminal makes a content request to the IP address for which an answer has been obtained. At the time of name resolution and content request, packets are transferred according to the IP routing table set in the client terminal.
[0033]
【The invention's effect】
As described above, according to the present invention, by using the preferential selection name server system, the content provided on the content network can be provided either as a copy of the content existing on the Internet or a content provided only on the content network. It becomes.
[Brief description of the drawings]
FIG. 1 is a network configuration diagram showing an embodiment of the present invention.
FIG. 2 is a block diagram for explaining functions of a client terminal according to an exemplary embodiment of the present invention.
FIG. 3 is a flowchart showing an operation when resolving a resolver name of a client terminal according to an exemplary embodiment of the present invention;
[Explanation of symbols]
10 Client terminal 20 Client terminal 30 ISP (Internet Service Provider) -A
31 Name server 32 Name server 40 ISP-B
41 Name Server 42 Name Server 50 Content Network 51 Name Server 100 Internet

Claims (5)

A client terminal equipped with a plurality of drivers for communicating with a predetermined network;
Means for prioritizing and selecting a name server to be accessed by the client terminal for name resolution when the client terminal is connected simultaneously with a network configured with different connectable address systems. Preferred name server system characterized by that. A client terminal connected to the Internet via an Internet service provider and connected to a content network independent of the Internet configured by a private address;
A driver that is provided in the client terminal, designates a name server provided in the Internet service provider, and a driver that designates a name server provided in the content network;
A priority selection name server system, comprising: means for specifying a priority order of name servers which are provided in the client terminal and go to name resolution queries via the drivers. A client terminal equipped with a plurality of drivers for communicating with a predetermined network;
A plurality of networks configured by different address systems to which the client terminal can be connected;
A name server existing in each network set in the client terminal,
In the system for selecting a name server that the client terminal accesses for name resolution,
Means for specifying the priority of the name server that the client terminal goes to inquire about name resolution;
A method for setting the relationship between the name server and the priority order for the name resolution inquiry individually for each client terminal,
Means for accessing a new name resolution request in order from the first priority specified in advance;
A means for transitioning to a name server whose priority is one lower when the name to be appealed is not resolved by the specified name server;
Means to prevent the priorities specified in advance from being changed by external factors;
A priority selection name server system comprising: means for ending name resolution when name resolution cannot be performed by all designated name servers. Means for setting a different IP address for each driver;
A client terminal having a means for uniquely corresponding to a name server accessed for each driver,
A means for uniquely setting a network address and a driver by setting an IP routing table of the client terminal;
A means for selecting a driver corresponding to a network to be accessed by referring to the IP routing table of the client terminal when the client terminal transmits an IP packet and accessing the target network via the driver; The preferential selection name server system according to claim 3, wherein: A plurality of drivers having means for setting different IP addresses for each driver, and means for corresponding name servers to be accessed for each driver;
An IP routing table having means for associating a network address with a driver;
A means for specifying the priority order of the name servers to be accessed, a means for preferentially selecting the designated name servers, and a name server of the next priority order is automatically inquired if the name server does not resolve the name. A client terminal comprising: a resolver having means and means for finishing name resolution if name resolution cannot be performed by all designated name servers.

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