JP2008219187A - Route information changing method, route information changing device, and route information changing program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily change route information to be advertised to a local AS and other ASs. <P>SOLUTION: A route information changing device 100 which gathers the route information of a router 10R is installed in an AS. When receiving a route information change request from the outside, the route information changing device 100 retrieves a route indicated in the route information changing request from a routing table in a storage unit. Then the property information of the retrieved route information is changed. For example, a community property is changed to NO-EXPORT. Further, the priority of the route information is made high and new route information is generated. Then the route information changing device 100 advertises the new route information to a router 10R in its AS and the router 10R advertises the new route information to other routers 10. Then the router 10 does not advertise the route information to other ASs based upon the community property NO-EXPORT of the route information. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to Internet route information change technology.

  The Internet is an organic connection of 10,000 or more ASs (autonomous systems) operated by ISPs (commercial providers, Internet service providers) and different organizations such as companies and universities. The ASs are connected by a dedicated line or IX (Internet eXchange).

  AS network connection device (router) exchanges each other's route information by BGP (Border Gateway Protocol), and determines the route for transferring data to a predetermined network based on the exchanged route information. To do. This route information includes a prefix and a path attribute. This prefix is also called a route, and is information indicating an IP (Internet Protocol) address space as a destination by a network address and a netmask length of the network address (hereinafter also referred to as a route length). The path attribute is attribute information of the route added to the route information, such as an AS path attribute. The AS path attribute is information indicating a list of AS numbers of ASs that are passed through to reach the destination AS.

  BGP is a path vector type routing protocol, and route information advertised by a certain AS propagates each AS hop-by-hop and spreads throughout the Internet. For example, in the process of propagation of this route information, each AS router adds the AS number of its own AS to the AS path attribute. In this way, path control based on each AS's own operation policy is performed by performing path attribute operations, path filtering, and the like in each AS.

  However, BGP does not have a function for confirming the correctness of propagation path information. Therefore, once incorrect route information is advertised due to an operator setting mistake or malicious setting, the incorrect route information is propagated to the entire Internet.

  A specific example of advertising incorrect route information is route hijacking. This is because a certain AS is advertising a route for a network address that is legitimately assigned by a network address management organization, and an AS that is not assigned a network address routes that network address or a part thereof. is there.

  When this route hijacking occurs and incorrect route information propagates throughout the Internet, the packet that should be transferred to the network address is transferred to the AS that advertised the incorrect route information. For this reason, a failure occurs in communication with the AS to which the network address is properly assigned.

  This path hijack will be described in detail with reference to the drawings. FIG. 1 is a diagram cited for explaining the path hijacking.

  Here, AS-A (AS number “1000”), AS-B (AS number “2000”), AS-C (AS number “3000”), AS-D (AS number “4000”) and AS-X Each router (AS number “5000”) exchanges route information with each other and creates a route table. For example, the AS-A router creates a routing table as indicated by reference numeral 1001. Although illustration is omitted here, the route information of this route table includes various path attributes such as the AS path attribute described above. Each AS router transfers packets based on the route table created in this way.

  If the AS-X router advertises a part of the AS-D route by mistake, the prefix “10.4” is sent to the router (for example, the AS-A router) to which the route information of this route has arrived. The information that the AS path attribute of “.128.0 / 17” is “2000 3000 5000” is written in the route table (see the hijack route indicated by reference numeral 1003).

  In other words, according to the route information indicated by reference numeral 1002 in FIG. 1, the packet addressed to the prefix “10.418.0 / 17” transmitted from the AS-A is originally transmitted via the AS-B to the AS. -D, when the hijacking route indicated by reference numeral 1003 in FIG. 1 is selected, the AS-B is sucked into the AS-X via the AS-C, and the packet is sent to the AS-D. Will not arrive.

  Note that when the router of each AS transfers a packet, it is not the original advertising route (“10.4.0.0/16”) indicated by reference numeral 1002, but the hijacking route (“10.4. .128.0 / 17 ") is selected because the router uses the longest match rule to select route information with a longer netmask length when there are multiple routes including the destination address in the route table. It is.

  When such a path hijacking occurs, the damaged AS-D operator or the like asks the AS-X operator to send incorrect path information (hijack path path information) to this AS-X router. It will be a full-fledged deal to be deleted from. However, it may not be possible to contact the AS-X operator, and it may take time to deal with it.

  Therefore, when the occurrence of path hijacking is detected in the own AS, it is important to first prevent the path information of the hijack path from propagating to other ASs. As described above, the following technique has been proposed as a technique for preventing the route information of the hijack route from being propagated to other ASs. This technique will be described with reference to FIG.

  FIG. 2 is a diagram cited for explaining the prior art. In FIG. 2, the description of AS-A in FIG. 1 is omitted.

  As shown in FIG. 2, AS-C includes four routers 10 (10R, 10A, 10B, 10C). The AS-B includes a router 10Y, and the AS-D includes a router 10D. Further, the AS-X includes a router 10X.

  The AS-C router 10R is connected to the routers 10A, 10B, and 10C, and the router 10C is connected to the AS-C router 10Y. The router 10A is connected to the AS-X router 10X. The router 10R is a route reflector that reflects route information, and establishes an iBGP (internal Border Gateway Protocol, internal BGP) session with the routers 10A, 10B, and 10C to exchange route information. In addition to the iBGP session with the router 10R, the router 10C establishes an eBGP (external Border Gateway Protocol, external BGP) session with the AS-B router 10Y to exchange route information. In addition to the iBGP session with the router 10R, the router 10A also establishes an eBGP session with the AS-X router 10X to exchange route information. Here, in order to simplify the explanation, the router 10R is used as a route reflector. However, the router 10R is not used as a route reflector, and the routers 10R, 10A, 10B, and 10C have a full mesh and establish an iBGP session. Information may be exchanged.

  Further, in FIG. 2, when the AS-X router 10X advertises the route information of the hijack route (for example, “10.418.0 / 17”) to the AS-C router 10A, this route information. Follows the route of router 10A → router 10R → router 10C and reaches router 10Y of AS-B.

  Here, in order to prevent the AS-C operator from spreading the hijack route to other ASs (for example, AS-B), the community attribute in the route information of the hijack route is “NO-EXPORT”. Information only needs to be given. This community attribute is attribute information for limiting the advertising range of route information, and is defined in RFC1997. The “NO-EXPORT” is community attribute information indicating that this route information is not advertised to other ASs.

  Thus, the router 10C that has received the route information with “NO-EXPORT” as the community attribute does not advertise this route information to other AS routers (for example, the AS-B router 10Y). As a result, when the AS-B router 10Y receives the advertisement of the route information of the prefix “10.4.0.0/16” which is the correct route information from the AS-D, the route based on the correct route information. Take control.

Here, in order not to spread the hijacking route from the AS (for example, AS-C in FIG. 2) that has received the advertisement of the hijacking route to other ASs, among the routers in the own AS. It is necessary to assign “NO-EXPORT” to the community attribute in the router (for example, router 10A) that has received the jack route. In other words, among the AS routers 10, it is necessary to assign “NO-EXPORT” to the community attribute of the hijack route at the entrance router 10 where the hijack route enters first. This is because if a router other than the entrance (for example, the router 10C) adds “NO-EXPORT” to the community attribute of the hijack route, it is high to another AS (for example, AS-B) connected from the router 10C. This is because the jack path does not spread, but there is a possibility that the hijack path may spread from other routers 10 (for example, the router 10B) to other ASs. Here, for example, a method in which the router 10C advertises again the route information in which “NO-EXPORT” is added to the community attribute of the hijack route to the router 10 in its own AS (in AS-C) is also conceivable. However, since the router 10 equipped with BGP cannot advertise again the route information advertised by iBGP from the router 10 in its own AS (see Non-Patent Document 1), it cannot take such a method.
Sam Harabi et al., “Internet Routing Architecture”, 2nd edition, Softbank Publishing, August 22, 2001, p142

  In this way, in order to change the route information advertised from other ASs and propagate the changed route information to other ASs connected from the own AS, the router (entrance) that has received the route information from other ASs. Router) and the routing information needs to be changed in the identified router. However, when there are a large number of routers in the AS, there is a problem that it is difficult to specify a router for changing the route information, and it takes time to change the route information.

  An object of the present invention is to solve the above-described problems and to provide means for facilitating change of route information advertised to the own AS and other ASs.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a route information changing method for changing route information exchanged by BGP (Border Gateway Protocol), and is provided in a route information processing device for exchanging the route information. The connected route information change device acquires route information held by the route information processing device, updates the route information in the storage unit of the route information change device, the prefix of the route to be changed, and the change A step of receiving a route information change request indicating change contents of attribute information of the target route, a step of searching the route information of the prefix indicated in the route information change request from the route information of the storage unit, and the reception Based on the route information change request, the attribute information of the searched route information is changed, and the priority in the route information whose attribute information is changed is determined as the priority. Generating a route path information is set higher than the information, the generated route information, and the route information change method characterized by performing a step of advertising to the route information processing apparatus.

  The invention according to claim 4 is a route information changing device connected to a route information processing device for exchanging route information exchanged by BGP (Border Gateway Protocol), the route information held by the route information processing device. A path information collection unit that acquires path information held by the path information processing apparatus and updates path information in the storage unit of the path information change apparatus And the route information of the prefix indicated in the route information change request when the route information change request indicating the change contents of the attribute information of the route to be changed and the attribute information of the change target route is received. Search from the route information of the part, based on the route information change request, change the attribute information of the searched route information, the priority in the route information changed this attribute information, Generates route information set higher than the serial search route information, the generated route information, and the route information changing device, characterized in that it comprises a path information generation unit for advertising to the routing information processing apparatus.

  In this way, the route information change device is provided separately from the route information processing device, and the route information change device collects the route information of the route information processing device and stores it in the storage unit. When the route information change device receives the route information change request, the route information change device retrieves the route information that is the subject of the change request from its own storage unit. Next, the route information changing device changes the attribute information in the searched route information, and the priority of the route information (for example, the value of the local prefix (Local_Pref) attribute) is higher than that of the searched route information. Route information is generated and advertised to each route information processing device. Each route information processing apparatus that has received such route information selects route information with a high priority and advertises the route information even if route information related to the same route is received, for example. Thus, when the route information advertised from another AS is changed and advertised to the local AS and the other AS, it is not necessary to specify a route information processing apparatus that changes the route information. That is, it is possible to reduce time and effort required for changing the route information advertised to the own AS and other AS.

  According to a second aspect of the present invention, in the route information changing method according to the first aspect, the step of generating the route information includes, based on the route information change request, among the attribute information of the searched route information. The route information changing method is characterized in that NO-EXPORT is added to the attribute, and route information in which the priority in the route information whose attribute information has been changed is set higher than that of the searched route information is generated.

  According to a fifth aspect of the present invention, in the route information changing device according to the fourth aspect, the route information generating unit is configured to select a community among the attribute information of the searched route information based on the received route information change request. The route information changing device is characterized in that NO-EXPORT is added to the attribute, and route information in which the priority in the route information whose attribute information is changed is set higher than the searched route information is generated.

  In this way, for example, when changing the route information attribute information so as not to be diffused to other ASs, such as route information of the hijack route, which is not to be diffused to other ASs, the route information This eliminates the need to specify the route information processing apparatus that changes the attribute information of the route information. That is, it is possible to reduce the time and effort for preventing unauthorized route information and the like from being diffused to other ASs.

  According to a third aspect of the present invention, in the route information changing method according to the first or second aspect, a step of receiving a route information change release request indicating a prefix of the route information to be changed, and the route information And a step of advertising a withdraw message including a prefix indicated in the change cancellation request to the route information processing apparatus.

  According to a sixth aspect of the present invention, in the route information changing device according to the fourth or fifth aspect, the route information generating unit receives a route information change release request indicating a prefix of the route information to be changed. Then, the route information change device is characterized in that the withdraw message including the prefix indicated in the route information change release request is advertised to the route information processing device.

  In this way, the route information changing device can easily release the change of the route information once changed.

  According to a seventh aspect of the present invention, there is provided a route information change program that causes a computer that is a route information change device to execute the route information change method according to any one of the first to third aspects. did.

  According to such a route information change program, the route information change method according to any one of claims 1 to 3 can be executed by a computer that is a route information change device.

  According to the present invention, a route information change device is connected to an AS router (route information processing device), and the route information change device changes the attribute information of the route information and increases the priority of the route information. To generate and advertise detailed route information. Then, the router that has received the advertisement of the new route information selects the new route information rather than the original route information based on the priority value, and uses the selected route information for the other route information. Advertise to the router. Accordingly, it is not necessary to specify a router for changing the route information and to set the change to the route information for the specified router, so that the route information can be changed promptly.

  For example, in an AS that receives illegal route information such as route information of a hijack route, it is not necessary to specify a router for changing the route information when the route information is not spread to other ASs. We can respond promptly.

  Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described.

  FIG. 3 is a diagram illustrating a configuration example of a system including the route information generation apparatus according to the present embodiment. The configuration of the system will be described with reference to FIG. As shown in FIG. 3, the system includes AS-X (AS number “5000”), AS-C (AS number “3000”), AS-B (AS number “2000”), and AS-D (AS number “ 4000 "). Each router 10 exchanges route information using the above-described BGP (eBGP and iBGP).

  AS-B includes a router 10Y, and AS-D includes a router 10D. Further, the AS-X includes a router 10X. The AS-C includes four routers (route information processing devices) 10 (10R, 10A, 10B, 10C) and a route information change device 100. The router 10R is a route reflector, and establishes an iBGP session with the routers 10A, 10B, and 10C and the route information change device 100 to exchange route information. In addition to the iBGP session with the router 10R, the router 10C establishes an eBGP session with the AS-B router 10Y to exchange route information. In addition to the iBGP session with the router 10R, the router 10A establishes an eBGP session with the AS-X router 10X to exchange route information.

  Here, for simplicity of explanation, the router 10R is used as a route reflector. However, the router 10R is used as a normal router, and the routers 10R, 10A, 10B, and 10C and the route information changing device 100 are full mesh and iBGP. A session may be established to exchange route information.

  The route information exchanged between each router 10 and the route information change device 100 includes a prefix attribute (prefix) and a path attribute. The prefix is also called a route, and includes a network address and a netmask length of the network address (hereinafter also referred to as a route length). The path attributes include an AS path attribute, a community attribute, a Local_Pref (local prefix) attribute, and the like. The local prefix attribute indicates a priority when selecting a route of the destination network when there are a plurality of routes for the same destination network. That is, in each router 10, when there are a plurality of routes for the same destination network, a route having a larger local attribute value is preferentially selected.

  The route information changing device 100 acquires (collects) route information from the router 10 connected to the route information changing device 100, and stores the acquired route information in a storage unit (described later). Then, the route information changing device 100 uses the route information stored in the storage unit to generate and advertise new route information. The advertised new route information is propagated through the router 10 connected to the route information changing device 100 and to other ASs and spreads.

  Here, an outline of the operation of the system shown in FIG. 3 will be described. Here, the case where AS-X advertises “10.4.12.88.0 / 17”, which is a part of the route in AS-D, by mistake will be described as an example. In addition, it is assumed that the route information change device 100 has received a route information change request for adding the “NO-EXPORT” community attribute to the route information related to “10.418.0 / 17”. .

  The AS-X router 10X erroneously advertises the route information of “10.128.0 / 17” (hijacking route), which is originally part of the AS-D route, to the AS-C router 10A. Then, this route information reaches the router 10R. The route information changing device 100 acquires route information of the hijack route via the router 10R. Then, when the route information change device 100 refers to the route information change request and determines that the route information of the hijack route is the route information to be changed, based on this route information, the “NO-EXPORT” community attribute Is added, and new route information is generated by increasing the Local_Pref attribute value. That is, new route information in which attribute information is changed is generated. Then, when the new route information is advertised to the router 10R, the route information changing device 100 is advertised to each router 10 in its own AS (AS-C) via this router 10R. By doing in this way, even if the hijacking route is advertised to the router 10 (for example, the router 10C) in the self AS (AS-C), the router 10C is more able to set the Local_Pref attribute value. High route information (route information with the “NO-EXPORT” community attribute) is selected as the optimum route. Then, the router 10C performs a route control process based on the attribute information of the selected route information. That is, the router 10C does not advertise the route information to which the “NO-EXPORT” community attribute is given (route information of the hijack route) to other ASs.

Specifically, the router 10C advertises cancellation (withdraw) of the prefix indicated by the route information to another router 10 by a BGP withdraw message (see RFC1771). In other words, the router 10 (
For example, the router 10Y) recognizes that the route information related to the prefix received so far has been canceled. Thereby, the router 10Y of AS-B can perform normal communication based on the correct route information “10.4.0.0/16” advertised from AS-D. Further, when the optimum route (best path) is lost due to the reception of the withdraw message, the router 10 advertises the withdraw message to other routers 10. As a result, the route information after the change is also selected as the best path in the other routers 10.

  Next, the route information changing device 100 will be described in detail with reference to FIG. FIG. 4 is a functional block diagram of the path information changing device of FIG.

  As shown in FIG. 4, the route information changing device 100 includes an input / output unit 11 that controls input / output of various data such as route information and route information change requests, route information collection, and route information whose attribute information has been changed. A processing unit 12 to be generated and a storage unit 13 for storing a route table 131 showing route information are provided. The route information change request is information indicating a change target route (change target prefix) and details of the change.

  The input / output unit 11 includes an input / output interface for performing data input / output with the router 10 and the like. The processing unit 12 is realized by a program execution process by a CPU (Central Processing Unit) included in the route information change device 100, a dedicated circuit, or the like. Further, the storage unit 13 includes a storage medium such as a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), and a flash memory. When the route information change device 100 is realized by program execution processing, the storage unit 13 stores a route information change program for realizing the function of the route information change device 100.

<Input / output unit>
When the input / output unit 11 receives route information from the router 10 (for example, the router 10R in FIG. 3) connected to the route information change device 100 or a route information change request (route information change request information) from an external device. The information is transferred to the processing unit 12. The route information change request may be received from an external device (not shown), or may be directly input by an operator using an input device or the like. When the input / output unit 11 receives new route information generated by the processing unit 12, the input / output unit 11 transmits (advertises) the route information to the router 10.

  FIG. 5 is a diagram illustrating a route information change request according to the present embodiment. As indicated by reference numeral 501 in FIG. 5, the route information change request includes a change target route (change target prefix) and the content of the change. For example, information indicating that “NO-EXPORT” is added to the community attribute of the route information of the prefix to be changed “10.418.0 / 17” is shown.

<Processing unit>
Returning to the description of FIG. The processing unit 12 controls the entire route information change device 100 and includes a route information collection unit 121 and a route information generation unit 122. The processing unit 12 includes BGP (eBGP and iBGP) as a route information exchange protocol.

  When the route table (not shown) of the router 10 connected to the route information changing device 100 is updated, the route information collection unit 121 receives the updated route information. Then, the route information collection unit 121 updates the route table 131 of the storage unit 13 based on the received route information. That is, the route information collection unit 121 creates the same route table 131 as the route table of the router 10 in the storage unit 13.

  When receiving the above-described route information change request, the route information generation unit 122 reads the route information of the change request target prefix from the route table 13. Then, in accordance with the route information change request, the attribute information of the read route information is changed to generate new route information. The route information generation unit 122 advertises the generated new route information to the router 10 via the input / output unit 11. For example, the route information generation unit 122 generates route information in which “NO-EXPORT” is added to the community attribute of the route information of the change target prefix “10.418.0 / 17”, and the generated route information Is advertised to the router 10R via the input / output unit 11.

<Storage unit>
The storage unit 13 stores a route table 131. The route table 131 will be described with reference to FIG. FIG. 6 is a diagram illustrating the route table of FIG. As illustrated in FIG. 6, the route table 131 includes one or more pieces of route information, and each route information includes a prefix and a path attribute of the prefix. Here, the path attribute indicates an AS path (AS path attribute), a community (community attribute), and a local prefix (local prefix attribute), but is not limited thereto.

  For example, in the route information indicated by reference numeral 601 in FIG. 6, the AS path of the prefix “14.14.18.0/17” is “5000”, the community is not particularly set, and the local prefix is “ 100 ".

<Processing procedure>
Next, the processing procedure of the route information changing apparatus 100 will be described using FIGS. 7 and 8 with reference to FIGS. FIG. 7 is a flowchart showing a processing procedure of the route information changing apparatus of FIG. FIG. 8 is a diagram illustrating the changed route information generated by the route information changing device of FIG.

  Although the description is omitted in the flowchart of FIG. 7, it is assumed that the route information collection unit 121 updates the route table 131 as needed when receiving route information from the router 10.

  First, the route information generation unit 122 of the route information change device 100 waits for reception of a route information change request (S701). When the route information change request is received (yes in S701), the route information indicated in this route information change request. Are extracted from the routing table 131 (S702). That is, the route information generation unit 122 searches the route table 131 for the route information of the change target prefix and extracts it. Note that when the route information generation unit 122 has not yet received a route information change request (No in S701), the processing in S702 is not yet executed.

  For example, the route information generation unit 122 performs a route information change request (“NO-EXPORT” for the route attribute community attribute of the change target prefix “10.418.0 / 17” as indicated by reference numeral 501 in FIG. 6) is extracted as route information of the prefix to be changed from the route table 131 illustrated in FIG. 6 as the route information of the prefix (“10.4.128.0/17”) indicated by reference numeral 601. .

  Returning to the description of FIG. When the route information generation unit 122 succeeds in extracting the route information of the change target prefix from the route table 131 (Yes in S702), the route information generation unit 122 generates the route information in which the attribute information of the extracted route information is changed based on the route information change request. (S703). Then, the changed route information is advertised to other routers 10 (S704).

  For example, the route information generation unit 122 changes the route information based on the route information change request indicated by reference numeral 501 in FIG. 5 and generates the route information indicated by reference numeral 801 in FIG. That is, the prefix “10.4.18.0/17” of the route information indicated by reference numeral 601 in FIG. 6 and the AS path “5000” remain unchanged, the community is “NO-EXPORT”, and the local prefix value is the original value. The route information changed to “101” obtained by adding 1 to the value is generated. Then, the route information generation unit 122 advertises the route information generated in this way to the router 10 (for example, the router 10R) connected to the route information change device 100.

  Here, the reason why the route information generation unit 122 advertises route information obtained by adding “1” to the local prefix value is as follows. That is, when the router 10 (10R) selects an optimum route from a plurality of pieces of route information, the route is selected with reference to various path attributes (AS path, community, local prefix, etc.) included in the route information. Here, the information that the router 10 that implements BGP refers to most preferentially among these AS path attributes is a local prefix. In other words, if the route information generation unit 122 generates route information with a higher local prefix value and advertises it to the router 10 (10R), the router 10 (10R) determines the optimum route as the changed route. Select the route information. Then, the optimum route selected by the router 10R is advertised to other routers 10 in its own AS. Then, the router 10 at the boundary with the other AS refers to “NO-EXPORT” of the route information community of the optimum route, and does not advertise this route information to the other AS. Here, the case where the route information generation unit 122 increases the local prefix value of the route information by “1” has been described as an example, but may be increased by “2 or more”.

  In addition, although the case where the community attribute value among the path attributes of the route information is changed has been described as an example here, the present invention is not limited to this. For example, among the path attributes included in the route information, an AS-PATH (AS path) attribute, an ORIGIN attribute (an attribute indicating the AS number of the AS from which the route information starts), a NEXT_HOP attribute (used as the next hop for the prefix) Attribute indicating the IP address of the router to be used), ATOMIC_AGGREGATE attribute (attributes to be given when the router receives route information of a duplicate route, selects route information with a short prefix length for some policy, and advertises it) Etc.), and can be applied to various path attribute changes. Even in that case, the route information generation unit 122 advertises the value of the local prefix of the change target route by increasing it from the original route information. In this way, the route information changing device 100 connected to the router 10 advertises the route information in which the local prefix value is increased to the router 10, and the route information after the change is sent to the AS and the route information via the router 10. By spreading to other ASs, the route information in which the information of the path attribute is changed is preferentially selected over the original route information in the router 10 of each AS. That is, the router 10 of each AS performs route control based on this changed route information.

  Note that the route information changing apparatus 100 performs the following processing when canceling the change of the route information after changing the route information according to the above-described procedure.

  For example, the route information generation unit 122 of the route information change device 100 receives a change release target prefix as exemplified in Table 1 below as a route information change request (route information change release request) from an external device or the like, Information indicating the change contents (change release) is received. Next, the route information generation unit 122 generates a withdraw message including the prefix to be changed and advertises this message to the router 10 (10R).

  That is, when the route information generation unit 122 receives a route information change request (route information change release request) as exemplified in Table 1, the route information generation unit 122 sends the prefix “10.418.0 / 17” to the router 10R. Generate and advertise withdraw message to cancel the route.

  When the route information generating unit 122 generates such a withdraw message and advertises it to the router 10R, the withdraw message is also advertised to each router 10 via the router 10R. In other words, in each AS router 10 that has received the advertisement of such withdraw message, if there is route information of the prefix, it is deleted, and as a result, the optimum route (best path) is lost. The withdraw message is advertised to other routers 10. As a result, the route information of the prefix is deleted also in each AS router 10, and as a result, the change of the route information can be canceled. This route information change request (route information change release request) is transmitted to the route information change device 100 by using, for example, a terminal device (not shown) by an AS operator who has changed the route information.

  The route information changing apparatus 100 according to the present embodiment can be realized by a route information generation / advertisement program for executing the processing as described above, and the program can be read by a computer (such as a CD-ROM). Can be stored and provided. It is also possible to provide the program through a network such as the Internet.

It is the figure quoted in order to demonstrate path | route hijacking. It is the figure quoted in order to demonstrate a prior art. It is the figure which showed the structural example of the system containing the path | route information generation apparatus of this Embodiment. FIG. 4 is a functional block diagram of the route information change device in FIG. 3. It is the figure which illustrated the route information change request of this embodiment. FIG. 5 is a diagram illustrating the route table of FIG. 4. It is the flowchart which showed the process sequence of the path | route information change apparatus of FIG. It is the figure which illustrated the route information after the change which the route information change device of Drawing 4 generated.

Explanation of symbols

10 (10A, 10B, 10C, 10Z) Router (route information processing device)
DESCRIPTION OF SYMBOLS 11 Input / output part 12 Processing part 13 Storage part 100 Path information change device 121 Path information collection part 122 Path information generation part 131 Path table (path information)

Claims (7)

A route information changing method for changing route information exchanged by BGP (Border Gateway Protocol),
A route information changing device connected to the route information processing device exchanging the route information,
Obtaining route information held by the route information processing device and updating route information in a storage unit of the route information changing device;
A step of receiving a route information change request indicating a change of the route information of the route to be changed and the attribute information of the route to be changed;
Searching the route information of the prefix indicated in the route information change request from the route information of the storage unit;
Based on the received route information change request, the attribute information of the searched route information is changed, and the route information in which the priority in the route information whose attribute information is changed is set higher than that of the searched route information is generated. Steps,
A step of advertising the generated route information to the route information processing apparatus.   In the step of generating the route information, when changing the attribute information of the searched route information based on the received route information change request, NO-EXPORT is added to the community attribute of the route information. The route information changing method according to claim 1. Receiving a route information change release request indicating the prefix of the route information to be changed;
The route information changing method according to claim 1 or 2, wherein a step of advertising a withdraw message including a prefix indicated in the route information change release request to the route information processing apparatus is executed. A route information changing device connected to a route information processing device that exchanges route information by BGP (Border Gateway Protocol),
A storage unit for storing route information held by the route information processing apparatus;
An input / output unit for data input / output;
A route information collection unit that acquires route information held by the route information processing device and updates route information in a storage unit of the route information change device;
When a route information change request indicating the change contents of the route information to be changed and the attribute information of the change target route is received, the route information of the prefix indicated in the route information change request is received as the route of the storage unit. Route information retrieved from information, and based on the route information change request, the attribute information of the searched route information is changed, and the priority in the route information in which the attribute information is changed is set higher than that of the searched route information And a route information generation unit that advertises the generated route information to the route information processing device. The route information generation unit
5. The NO-EXPORT is added to the community attribute of the attribute information of the searched route information when the attribute information of the searched route information is changed based on the received route information change request. The route information change device described. The route information generation unit
When a route information change release request indicating a prefix of route information to be changed is received, a withdraw message including the prefix indicated in the route information change release request is advertised to the route information processing apparatus. The route information change device according to claim 4 or 5.   A route information changing program that causes a computer that is a route information changing device to execute the route information changing method according to any one of claims 1 to 3.

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