JPH1155307A - Router - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transmit and receive communication data by routing with secrecy with respect to a router as an inter-network connecting device for deciding the path of a datagram by an internet protocol. SOLUTION: A routing module designates a routing destination IP(internet protocol) address from a transmission destination network address and an arbitrarily set routing identifier based on a routing table, and transmits an IP datagram received from the IP module and this routing destination IP address to a prescribed IP module. It is constituted so that this routing table uses a value which masks this identifier.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a router, and more particularly, to an Internet Protocol (hereinafter, Internet Protocol).
The present invention relates to a router as an inter-network connecting device that determines a route of a datagram (packet) by IP.

The Internet is a large number of local area networks (LANs) and wide area networks (WANs).
This is a composite network in which networks such as twork) are interconnected in a mesh form by a router (or gateway) which is an inter-network connecting device.

[0002] IP is based on OSI (Open Systems Interconne).
ction: Open system-to-system connection) and a network layer that is located above the data link layer, and is a protocol that regulates communication between Internet routers and between nodes and routers.

[0003] A router determines a route of an Internet datagram (hereinafter, referred to as an IP datagram) received from a connected network based on an IP route control function including route information, and separates the IP datagram. To the network.

In the Internet, Ethernet
(Ethernet), Fiber Distributed Data Interface (FD)
Since actual communication is performed using an existing network such as a DI (Fiber Distributed Data Interface) and a dedicated line, the value of use is increasing and becoming more important.

[0005]

2. Description of the Related Art FIG. 21 shows the Internet constructed on a plurality of existing networks.
Is connected to networks 2, 3, and 4 by a router R1. These networks 2, 3, 4 are connected to networks 5, 6, 7 by a router R2, and the networks 5, 6, 7 are further connected to a network 8 including a node N2 by a router R3.

In the Internet, since a 32-bit Internet address (hereinafter, referred to as an IP address) is defined, each of the physical networks 1 to 8 can be regarded as a unified logical network which does not depend at all on its type. I can do it. Hereinafter, the types of the networks 1 to 8 will be described as Ethernet.

[0007] An IP address is composed of a pair of a unique network number in the entire Internet for identifying a network and a unique node number in the network for identifying a node. Therefore, each node on the Internet
It can be uniquely specified by the IP address.

[0008] For example, in FIG.
To 8 are network numbers 160.1.1 to 160.1.
8 respectively, so that node N1 is assigned the IP address 160.1.1.5.

[0009] The router R1 has a network 1
IP addresses 160.1.1.1-16 corresponding to # 4
0.1.4.1 has been assigned.

FIG. 22A shows an IP datagram which is a communication unit on the Internet.
The P datagram is composed of an IP header field and an IP data field. The datagram shown in the figure is represented by a 32-bit width.

[0011] The IP data field is a variable length data field carried by the IP datagram.
If the upper layer protocol is, for example, the TCP protocol, it is composed of a TCP header and data, and is interpreted by the TCP protocol.

The IP header field has a version (V
er; 4 bits), Internet header length (IHL;
4 bits), service type (TOS; 8 bits), total length (16 bits), identifier (ID; 16 bits), flag (FLG; 3 bits), fragment offset (1
3 bits), time to live (TTL; 8 bits), protocol number (8 bits), header checksum (16 bits), destination address (32 bits), source address (32 bits), option (variable length), And padding (variable length) fields.

Of these, the full length field particularly indicates the total length of the IP datagram including the header field and the data field in units of octets, with a maximum of 65,535.
Up to octets can be specified.

However, in general, existing networks and communication media used by the Internet have an upper limit on the data length that can be sent at one time, so that the total length of IP datagrams cannot exceed this upper limit.

Therefore, the length of a transferable IP datagram on the route is checked, and the IP datagram is sent as a fragmented fragment to reconstruct the original IP datagram at the final destination.

Each fragment is in the form of an IP datagram, and an identifier, a protocol number, a destination address, and a source address are included in the original IP datagram.
Copied from datagram. Then, at the time of reassembly, the identifier is used to identify a fragment of the same IP datagram.

Therefore, the caller assigns the identifier to the IP datagram so that the IP datagram having the combination of the protocol number, the destination address, and the source address having the same identifier value does not exist on the Internet. Become.

FIG. 22 (2) shows an Ethernet frame in which a preamble (8 octets) and a destination M
It consists of an AC address (6 octets), a source MAC address (6 octets), a type (2 octets), data (variable length from 46 to 1500 octets), and a frame check sequence (CRC, 4 octets).

The variable-length data field encapsulates and includes an IP header field and an IP data field of an IP protocol as an upper layer.

FIG. 23 shows an example of the configuration of a router, in particular, the router R1 shown in FIG. 21. The circuit comprises an Ethernet module 11, an IP module 21, an ARP module 31, and an ARP cache T1 connected to the network 1. 41, an Ethernet module 12, an IP module 22, an ARP module 32, and an ARP cache T for connecting to the network 2.
2; circuits 43 and 44 for connecting to networks 3 and 4 respectively; a routing module 10; and a routing table TR1.

The Ethernet modules 11 to 14 (1
3 and 14 belong to the data link layer, and IP modules 21 to 24 (23 and 24 are not shown) and ARP
Modules 31-34 (33, 34 not shown) and AR
P caches T1 to T4 (T3 and T4 are not shown) belong to the network layer (or IP layer).

FIG. 24A shows the routing table T.
This shows an example of the configuration of R1, in which a "routing destination IP address" corresponding to a "transmission destination network address" is specified.

FIG. 24B shows an example of the configuration of the ARP cache (table) T1, in which a “MAC address” corresponding to an “IP address” is shown.

Hereinafter, the operation of the router R1 shown in FIG. 23 will be described with reference to the flowcharts of FIGS.

In FIG. 25, the Ethernet module 11
Receives an Ethernet frame including an IP datagram from the network 1 (steps S100 to S1).
02), and transmits the Ethernet module to the IP module 21 (S103).

In FIG. 26, the IP module 21
When the Ethernet frame is received from the Ethernet module 11 (S200 to S202), the process proceeds to step S310 in FIG. 27, where the destination IP address in the frame and the I
A comparison is made with the P address (S301).

If the addresses match, it is checked whether or not the same IP address as that in the Ethernet frame (IP datagram) is in the ARP cache T1 (S302). The MAC address corresponding to the address is acquired, the destination MAC address of the Ethernet frame is updated to the acquired MAC address (S303), and the Ethernet frame is transmitted to the Ethernet module 11 (S304).

In FIG. 25, the Ethernet module 11 having received the Ethernet frame (IP datagram) from the IP module 21 transmits the Ethernet frame to the network 1 (S100, S101, S100).
105). Then, this Ethernet frame is received by the node having the specified MAC address.

On the other hand, if the destination IP address in the frame is not in the ARP cache T1 in step S302 in FIG.
The address is transmitted (S305), and the ARP module 3
Then, the system waits for a response of the IP address / MAC address from the server 1 (S306).

In FIG. 28, the ARP module 31
Receives the destination IP address from the IP module 21 (step S400), creates an ARP request datagram (step S401), transmits an ARP request to the Ethernet module 11 (step S402), and receives an ARP response Ethernet frame. The state becomes a waiting state (S403).

In FIG. 25, the Ethernet module 11 receives an Ethernet frame from the ARP module 31 (steps S100 and S101) and transmits a broadcast ARP inquiry Ethernet frame to the network 1 (steps S102 and S104).

The corresponding node receives the ARP inquiry Ethernet frame, puts its own MAC address on the ARP response Ethernet frame, and returns it to the Ethernet module of the router R1.

The Ethernet module 11 receives the ARP response Ethernet frame, and
Is transmitted to the module 31 (S100, S101, S
102, S104).

In step S403 of FIG.
The P module 31 receives the ARP response Ethernet frame and sets the source IP address and the MAC address to I
Transmit to P module 21 and ARP cache T1
(Steps S404 and S405).

In step S306 of FIG.
The module 21 receives the IP address / MAC address, updates the destination MAC address of the Ethernet frame with the received MAC address (S307), and transmits the received frame to the Ethernet module 11 (S308).

Thereafter, the frame is transmitted to the node having the MAC address via the Ethernet module 11 and the network 1 in the same manner as the steps after steps S303 and S304.

On the other hand, in step S301 of FIG.
If the destination IP address in the received frame does not match the IP address of the own module, a received Ethernet frame (IP datagram) is transmitted to the routing module 10 (S309).

In FIG. 29, the routing module 10 receives an Ethernet frame (IP datagram) from the IP module 21 (step S50).
0), it is determined whether the same address as the network address included in the destination IP address is present in the routing table TR1 (S501).

If there is, the searched routing destination IP
An Ethernet frame (IP datagram) and a routing destination IP address are transmitted to, for example, the IP module 22 connected to the network 2 having the network address included in the address (S513).

In FIG. 26, the IP module 22
An Ethernet frame (IP datagram) is received from the routing module 10 (step S200,
S201, S203).

In step S600 in FIG. 30, the routing destination IP address is the same as the transmission destination IP address in the Ethernet frame (IP datagram) (step S6).
01) and determines whether the same IP address as the destination IP address is in the ARP cache T2 (S6).
02).

If there is, the destination MAC address of the received Ethernet frame is updated from the ARP cache T2 with the MAC address corresponding to the destination IP address, and the received frame is transmitted with the MAC address corresponding to the IP address of the own IP module 22. An Ethernet frame with the original MAC address updated is created (S603).

The Ethernet frame is transmitted to the Ethernet module 12 (S604). In the subsequent operation, the Ethernet frame is transmitted to the node having the destination MAC address via the network 2 in the same manner as in step S308 and subsequent steps in FIG.

In step S602 of FIG.
When the same IP address as the transmission destination IP address is not in the ARP cache T2, the module 22 transmits the transmission destination IP address to the ARP module 32 and inquires of the MAC address (S605).
Waits until a response is received from the server (S61).
0).

Upon receiving the IP address / MAC address from the ARP module 32, the IP module 22 updates the destination MAC address of the received frame with the received MAC address, and
The source MAC address of the received frame is updated with the MAC address corresponding to the address (step S611), and the received frame is transmitted to the Ethernet module 12 (step S611).
612). The subsequent operation is the same as the operation after step S604.

In step S601, the IP module 22 stores, in the ARP cache T2, when the routing destination IP address and the transmission destination IP address in the Ethernet frame (IP datagram) are not the same value and the same IP address as the routing destination IP address is in the ARP cache T2. It is determined whether or not there is (S606).

If there is, the MAC address corresponding to the routing destination IP address is used as the destination MAC of the received frame.
Update the address, and use the MAC address corresponding to the IP address of the own IP module with the source MAC of the received frame.
The address is updated (S607).

Then, the received frame is transmitted to the Ethernet module 12 (S608). The subsequent operation is the same as the operation after step S604.

In step S606, when the same IP address as the routing destination IP address does not exist in the ARP cache T2, the IP module 22 transmits the routing destination IP address to the ARP module 32, and inquires of the corresponding MAC address, asks the ARP module 32
(S609).

The subsequent operations in steps S610 to S612 are the same as described above, and the received frame is transmitted to the node of the routing destination MAC address (IP address).

In step S501 of FIG. 29, if there is not the same address, the IP address of the predetermined default router is regarded as the IP address of the routing destination, and the network address included in the IP address of the default router, for example, An Ethernet frame and the IP address of the default router are transmitted to the IP module 24 (not shown) connected to the IP module 4 (S502). In the subsequent operation, the received frame is transmitted to the default router of the network 4 in the same manner as the operation after step S513.

Hereinafter, in the Internet having the configuration shown in FIG. 21, the IP address connected to the network 8 from the node N1 whose IP address is 160.1.1.5 connected to the network 1 is 160.1.8. The routing operation of transmitting an IP datagram to the node N2 which is .5 will be described with reference to FIGS.

In FIG. 31, since the network address 160.1.8 included in the destination IP address 160.1.8.5 of the IP datagram is the address of another network 8, the node N1 A router R connected to the same network 1 whose address is registered as a connected default router (not shown)
1 (IP address 160.1.1.1) (broken line in the figure).

That is, on the Ethernet, the node N1
Is the MAC address 0A- corresponding to the IP address 160.1.1.1 from the own ARP cache in FIG.
0B-0C-0D-01-01 is obtained, and the IP datagram is encapsulated in an Ethernet frame whose destination MAC address is updated with this MAC address, and transmitted.

The router R1 compares the network address 160.1.8 contained in the destination IP address in the received IP datagram with the destination network address in the routing table TR3 in FIG. A destination IP address 160.1.2.2.2 is obtained (broken line in FIG. 31), and the received IP datagram is
IP address 160. Connected to network 2 via address (connection) 160.
The data is forwarded to the router R2 of 1.2.2 (broken line in the figure).

That is, as in the case of the node N1, the router R1 refers to the ARP cache of FIG. 31 (2) and sets the destination MAC address of the Ethernet frame to be transferred to the IP address 160.1.2 of the router R2. .2 MAC addresses 0A-0B-0C-0D-02
Set -02.

In the routing operation in the routers R2 and R3, which will be described later, the matching of the MAC address as the physical address from the IP address as the logical address is performed by the ARP cache (table) or the ARP module (protocol).

In FIG. 33, the router R2 receives the received I
Destination IP address in P datagram 160.1.
Network address 160.1.8 included in 8.5
And the "destination network address" in the routing table TR2 of FIG. 34 (1) is checked (broken line in FIG. 33).

As a result, the received IP datagram is sent to the router R3 connected to the network 5 specified by the “routing destination IP address” 160.5.1.2.
(Broken line in the figure).

In FIG. 35, the router R3 has a network address 160.1.8 included in the destination IP address in the received IP datagram and a “destination network address” in the routing table TR3 of FIG. 36 (1). And the corresponding “Routing destination IP
Address "is only the network address 160.1.8.

Therefore, the router R3 sends an address (connection) 16 to the network 8 connected to its own station.
Node N2 received via 0.1.8.1 (destination I
Transfer IP datagram addressed to P address 160.1.8.5) (broken line in FIG. 35)

As a result, the node N2 transmits the IP datagram transmitted by the node N1 to the network 1, the router R
1, the network 2, the router 2, the network 5, the router R3, and the network 8.

[0063]

A router has a routing table in which a destination network address and a routing destination IP address are registered on a one-to-one basis.
The network address included in the destination IP address in the datagram is compared with the destination network address in the routing table, and the IP datagram is transferred to the network of the network address included in the routing destination IP address of the matching data entry.

That is, the router always sends an IP datagram having the same destination IP address to the same network according to the routing table.

In addition, communication data destined for the same destination flowing on the Internet is usually divided into one IP datagram or a plurality of IP datagrams for communication, but is divided into a plurality of IP datagrams. Destination IP of all divided IP datagrams
The addresses are the same.

Therefore, it means that the contents of the entire communication data are known at one location on the communication route where the IP datagram can be monitored, and even if each IP datagram is encrypted, The possibility cannot be denied.

Accordingly, an object of the present invention is to transmit and receive communication data by confidential routing in a router that determines a datagram path by an Internet protocol.

[0068]

In order to solve the above problems, a router according to the present invention is connected to a network,
A plurality of IP modules for transmitting and receiving IP datagrams based on the routing destination IP address, and a routing identifier set arbitrarily for the same destination network address as the destination network address in the header of the datagram. The routing table specifying the address, the datagram received from the IP module, and the routing destination IP address specified from the routing table are connected to the network of the network address included in the routing destination IP address. It can be composed of a routing module for sending to the IP module.

In a conventional router, the same destination IP
The same routing is performed on the IP datagram of the address unless the registered data in the routing table in the router is changed.

Conversely, in order to allow IP datagrams having the same destination IP address to pass through different routes, different routing destination IP addresses may be specified in the routing table.

Therefore, according to the present invention, a plurality of I
When transmitting communication data divided into P datagrams from one node to another node, the I
Paying attention to the fact that the value of D (identifier) differs for each IP datagram, the structure of the conventional routing table shown in FIG. It is extended so that it can be divided into destination IP addresses.

The function of the routing module is
The extension is made to determine the routing destination IP address by including the value of the identifier in addition to the network address included in the transmission destination IP address in the P datagram.

As a result, a plurality of IP datagrams having the same destination IP address are
It is possible to distribute the data to a plurality of arbitrary communication routes for each value of the identifier in the datagram) and transmit it. "IP datagrams having the same destination IP address are always communicated on the same communication route." It is possible to solve the conventional problem and easily secure data confidentiality in IP routing.

In the present invention, the routing table may use a value obtained by masking a predetermined bit corresponding to the routing destination address of the identifier.

That is, as shown in FIG. 1, the routing table of the router according to the present invention has a “masked bit (shaded portion)” and a “masked ID” obtained by masking the “identifier” with the “mask bit”. (Shaded portion) ".

In this routing table, FIG.
Unlike the table of 4 (1), for example, for each “masked ID” 0001 to 000F different from the same “destination network address” 160.1.8, the “routing destination IP address” 1600.1.2.1 to 160 1.1
5.29 is supported.

The operation of the present invention when using the routing table illustrated in FIG. 1 will be specifically described below with reference to the flowchart illustrated in FIG.

The flowchart of FIG. 2 is different from the flowchart of FIG. 29 in that the functions are expanded as steps S503 and S504 instead of step S513 in FIG.

That is, in step S 503, the bitwise AN of the “mask bit” of the data entry of the same network address in the routing table and the identifier in the Ethernet frame (IP datagram)
Perform D operation to perform mask processing.

In step S504, bit AND
An Ethernet frame (IP datagram) is sent to the IP module connected to the network having the network address included in the “routing destination IP address” of the data entry in which the processing result matches the “masked ID” of the data entry in the routing table. ) And the retrieved routing destination IP address is transmitted.

As a result, it is possible to specify a routing corresponding to only a specific bit of the identifier.

That is, if, for example, only the lower 4 bits of the identifier are specified by a mask, a maximum of 16 different routes (networks) are connected to the router, and the datagram with the same destination IP address is distributed to each route. A routing table can be set.

[0083]

FIG. 3 to FIG. 20 show an embodiment of a router according to the present invention, in which a node N1 connected to a network 1 and a node N2 connected to a network 8 on the Internet having the same configuration as FIG. “1AB1”, “1CD2”, and “1EF3” with different identifiers
IP datagram (destination IP address: 16
0.1.8.5) shows an extended routing operation example of the routers R1 to R3 when transmitting (0.1.8.5).

Embodiment 1: IP datagram (identifier: 1)
AB1) In FIG. 3, the node N1 connected to the network 1
(IP address: 160.1.1.5) indicates that the transmission destination IP address (160.1.8.5) of the IP datagram is the address of the node N2 connected to the other network 8, so that The address is transmitted to the router R1 (160.1.1.1) connected to the same network 1 whose address is registered as the connected default router (broken line).

When the network 1 is Ethernet, the node N1 refers to its own ARP cache TN1 shown in FIG.
From 1.1.1, MAC address 0A-0B of router R1
After knowing -0C-0D-01-01 and updating the destination MAC address of the Ethernet frame with this MAC address, the above-described transmission operation is performed.

Generally, on each network, a frame (for example, an Ethernet frame) is transmitted / received using an IP address, which is a logical address, by a physical address (for example, a MAC address) corresponding to each network.

Thereafter, the transmission / reception operation is performed by the network layer I
The P address and the IP datagram will be described, and the MAC address and the Ethernet frame will be described in a simplified manner.

Router R1 Connected to Network 1
Compares the network address 160.1.8 contained in the destination IP address in the received IP datagram with the “destination network address” 160.1.8 in the routing table TR1 of FIG. , The identifier “1AB1” of the received IP datagram and the “mask bit” “000” of the routing table TR1 for the data entries having the same network address.
A mask process is performed by performing an AND operation for each bit with F ″.

Further, the router R1 determines that the result of the operation is “00”.
01 "and the" masked ID "" 0001 "refer to the" routing destination IP address "of the data entry (shaded portion).

Then, the IP address 160.1.
The IP datagram received by the router R2 connected to the network 2 designated by 2.2 is transferred via the address (connection) 160.1.1.2 (broken line).

This transfer is performed by obtaining the MAC address from the IP address according to the table in FIG.

In FIG. 5, the router R2 receives the
The network address 160.1.8 included in the destination IP address in the datagram is compared with the "destination network address" in the routing table TR2 in FIG. On the other hand, mask processing is performed by an AND operation for each bit of the identifier “1AB1” of the received IP datagram and the mask bit “000F” of the routing table.

The router R2 determines that the operation result “0001” is “masked I” in the shaded portion of the routing table TR2.
D "0001", the received IP datagram is sent to the "routing destination IP address" 160.2.5.
6 via the address 16.5.1.5.1 to the router R3 connected to the network 5 designated by
The MAC address is obtained from the table of (3) and transferred (broken line).

In FIG. 7, the router R3 determines whether the network address included in the destination IP address in the received IP datagram matches the “destination network address” in the routing table TR3 of FIG. 8A. Search for an entry (shaded area).

Then, "Routing destination IP address"
Since only the address 160.1.8 of the network 8 is set in the module of the own station (IP address 16
0.1.8.1) knows that an IP datagram should be sent to the network 8 to which it connects.

Then, the router R3 sends the received IP datagram to the node N2 connected to the network 8 via the address 160.1.8.1 connected to the network 8 by using the table shown in FIG. And transfers the MAC address (broken line).

Note that the routing table TR3 contains
Since there is no route other than the network 8 between the router R3 and the node N2, the "network address" 160.
"Mask bit" and "masked ID" corresponding to 1.8
Is not set, and only the same network address is set in the “routing destination IP address”.

As a result, the IP datagram (destination IP
Address: 160.1.8.5, identifier: 1AB1) is transmitted from the node N1 to the node N2 via the network 1, router R1, network 2, router R2, network 5, router R3, and network 8. Become.

Embodiment 2: IP datagram (identifier: 1)
In the case of CD2) In FIG. 9, the node N1 converts the IP datagram (identifier: 1CD2) into the IP datagram (identifier:
1AB1), the router R1 is configured as shown in FIG.
The MAC address is obtained from the table of (2) and transmitted (broken line).

The router R1 collates the network address contained in the destination IP address in the received IP datagram with the destination network address in the routing table TR1 of FIG. 10A, and the network addresses match. An AND operation for each bit of the received IP datagram identifier “1CD2” and the “mask bit” “000F” of the routing table TR1 is sequentially performed on the data entries.

The router R1 determines that the operation result “0002” is “masked I” in the shaded portion of the routing table TR1.
D "" 0002 ", the received IP datagram is sent to the" routing destination IP address "160.1.
10 via the address 160.1.3.1 to the router R2 connected to the network 3 designated by 3.2.
The MAC address is obtained from the table of (3) and transferred (broken line).

In FIG. 11, the router R2 is
1, the routing table TR2 of FIG.
, An AND operation for each bit of the identifier “1CD2” of the received IP datagram and the “mask bit” “000F” of the routing table TR2 is sequentially performed on the data entries having the same network address.

Then, the received IP datagram is sent to the router R3 connected to the network 6 corresponding to the routing destination IP address 160.1.6.2 in which the operation result “0002” matches, and the received IP datagram is shown in FIG. M from the table
Acquire and transfer the AC address (dashed line).

In FIG. 13, the router R3 compares the network address contained in the destination IP address in the received IP datagram with the destination network address in the routing table TR3 in FIG. And the node N2 connected to the network 8
The IP datagram is transferred via the address 160.1.8.1 by obtaining the MAC address from the table in FIG.

As a result, the IP datagram (destination IP
(Address: 160.1.8.5, identifier: 1CD2) is transmitted from the node N1 to the node N2 via the network 1, the router R1, the network 3, the router R2, the network 6, the router R3, and the network 8. Become.

Embodiment 3: IP datagram (identifier: 1)
In the case of EF3), in FIG. 15, the node N1 obtains the MAC address from the table of FIG. 16B and transmits the IP datagram to the router R1 (broken line).

The router R1 performs the AND operation for each bit between the “mask bit” in the routing table TR1 of FIG. 16 (1) and the identifier “1EF3” of the received IP datagram and “0003” and “masked”. The ID received by the router R2 connected to the network 4 designated by the “routing destination IP address” 160.1.4.2 is referred to by referring to the data entry (shaded portion) having the matching “ID”.
The P datagram is converted from the MAC of the table in FIG.
An address is obtained and transferred (broken line).

In FIG. 17, the router R2 is a router R2.
1 as well as the routing table TR2 in FIG.
, The network 7 specified by the “routing destination IP address” in the data entry portion indicated by shading
The MAC address is obtained from the table in FIG. 18B and transferred to the router R3 connected to the router R3 (broken line).

In FIG. 19, the router R3 specifies the “routing destination IP address” 160.1.8 of the shaded data entry part with reference to the routing table TR3 of FIG. The received IP datagram is sent to the node N2 connected to the network 8 via the address 160.1.8.1, as shown in FIG.
The MAC address is obtained from the table of (2) and transferred (broken line).

As a result, the IP datagram (destination IP
The address: 160.1.8.5, the identifier: 1EF3) is transmitted from the node N1 to the node N2 via the network 1, the router R1, the network 4, the router R2, the network 7, the router R3, and the network 8. Become.

As a result of Examples 1 to 3, it can be seen that IP datagrams having the same destination but different identifiers are transmitted to the destination through different routes. Therefore, confidential communication data routing is possible.

In the first to third embodiments, all datagrams having the same destination pass through the routers R1 to R3. However, all datagrams having the same destination are set to the same destination according to the configuration of the network and the setting of the routing table. It is also possible not to pass through a router.

[0113]

As described above, according to the router of the present invention, the routing module specifies the routing destination IP address from the destination network address and the arbitrarily set routing identifier based on the routing table. Received from the IP module
Since the P datagram and the routing destination IP address are configured to be sent to a predetermined IP module, datagrams having the same destination address can be transmitted / received through an arbitrary route different for each datagram, and communication data is concealed. It is now possible to send and receive with routing that has the potential.

In particular, by setting a large number of different routings, it is possible to distribute traffic more evenly and to assure communication performance.

Further, since the routing table uses a value obtained by masking a predetermined bit of the identifier, it is possible to set a routing only by a specific bit of the identifier.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a routing table in a router according to the present invention.

FIG. 2 is a flowchart illustrating an operation of a routing module in the router according to the present invention.

FIG. 3 is an operation sequence diagram (part 1) showing the first embodiment of the router according to the present invention on the Internet.

FIG. 4 is a table diagram (part 1) used in the first embodiment of the router according to the present invention on the Internet.

FIG. 5 is an operation sequence diagram (part 2) showing the first embodiment of the router according to the present invention on the Internet.

FIG. 6 is a table diagram (part 2) used in the first embodiment of the router according to the present invention on the Internet.

FIG. 7 is an operation sequence diagram (part 3) showing the first embodiment of the router according to the present invention on the Internet.

FIG. 8 is a table diagram (part 3) used in Embodiment 1 of the router according to the present invention on the Internet.

FIG. 9 is an operation sequence diagram (part 1) showing a second embodiment of the router according to the present invention on the Internet.

FIG. 10 is a table diagram (part 1) used in a second embodiment of the router according to the present invention on the Internet.

FIG. 11 is an operation sequence diagram (part 2) of Embodiment 2 of the router according to the present invention on the Internet.

FIG. 12 is a table diagram (part 2) used in the second embodiment of the router according to the present invention on the Internet.

FIG. 13 is an operation sequence diagram (part 3) showing the second embodiment of the router according to the present invention on the Internet.

FIG. 14 is a table diagram (part 3) used in the second embodiment of the router according to the present invention on the Internet.

FIG. 15 is an operation sequence diagram (part 1) showing a third embodiment of the router according to the present invention on the Internet.

FIG. 16 is a table diagram (part 1) used in a third embodiment of the router according to the present invention on the Internet.

FIG. 17 is an operation sequence diagram (part 2) showing the third embodiment of the router according to the present invention on the Internet.

FIG. 18 is a table diagram (part 2) used in a third embodiment of the router according to the present invention on the Internet.

FIG. 19 is an operation sequence diagram (part 3) illustrating the third embodiment of the router according to the present invention on the Internet.

FIG. 20 is a table diagram (part 3) used in the third embodiment of the router according to the present invention on the Internet.

FIG. 21 is a block diagram illustrating a configuration example of the Internet in which a plurality of networks are connected by a router.

FIG. 22 is a format diagram showing a configuration of an IP datagram and an Ethernet frame in a router.

FIG. 23 is a block diagram illustrating a functional configuration example of a router.

FIG. 24 is a configuration example of a routing table and an ARP cache in a conventional router.

FIG. 25 is a flowchart illustrating an operation example of an Ethernet module in a router common to the present invention and a conventional example.

FIG. 26 shows an I in a router common to the present invention and the conventional example.
It is a flowchart figure (the 1) which shows the operation example of a P module.

FIG. 27 shows an I in a router common to the present invention and the conventional example.
It is a flowchart figure (the 2) which shows the operation example of a P module.

FIG. 28 shows A in a router common to the present invention and the conventional example.
It is a flowchart figure which shows the operation example of an RP module.

FIG. 29 is a flowchart illustrating an operation example of a routing module in a conventional router.

FIG. 30 shows an I in a router common to the present invention and the conventional example.
It is a flowchart figure (the 3) which shows the operation example of a P module.

FIG. 31 is an operation sequence diagram (part 1) illustrating an operation example of a conventional router on the Internet.

FIG. 32 is a table diagram (part 1) showing a configuration example of a conventional routing table of a router and an ARP cache common to the present invention and the conventional example.

FIG. 33 is an operation sequence diagram (part 2) showing an operation example of a conventional router on the Internet.

FIG. 34 is a table diagram (part 2) showing a configuration example of a conventional routing table of a router and an ARP cache common to the present invention and the conventional example.

FIG. 35 is an operation sequence diagram (part 3) showing an operation example of a conventional router on the Internet.

FIG. 36 is a table diagram (part 3) illustrating a configuration example of a conventional routing table of a router and an ARP cache common to the present invention and the conventional example.

[Explanation of symbols]

 R1, R2, R3 Router 1-8 Network N1, N2 Node TR1 Routing table T1, T2, TN1 ARP cache 10 Routing module 11, 12 Ethernet module 21, 22 IP module 31, 32 ARP module The corresponding parts are shown.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Isamu Ishii 3-2-1, Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fujitsu Network Engineering Co., Ltd. (72) Inventor Yoshiyuki Sasaki 3-chome Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa No. 2 Fujitsu Network Engineering Co., Ltd. (72) Inventor Hiroyuki Hirayama 3-2-1 Sakado, Takatsu-ku, Kawasaki City, Kanagawa Prefecture Fujitsu Network Engineering Co., Ltd.

Claims (2)

[Claims] 1. A plurality of IP modules connected to a network for transmitting and receiving IP datagrams based on a routing destination IP address, and arbitrarily setting a destination network address identical to a destination network address in a header of the datagram. The routing destination I
A routing table specifying a P address; the datagram received from the IP module; and the routing destination IP specified from the routing table.
Address to the network of the network address included in the routing destination IP address.
A router comprising: a routing module for sending to a P module; 2. The router according to claim 1, wherein the routing table further has a value obtained by masking a predetermined bit corresponding to the routing destination address of the identifier.