Address reporting device and method for detecting authorized and unauthorized addresses in a network environment

• US 5,815,664 A
• Filed: 03/19/1996
• Issued: 09/29/1998
• Est. Priority Date: 03/20/1995
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Asano, Kazuo
• Primary Examiner(s): Bowler, Alyssa H.
• Assistant Examiner(s): Nguyen, Dzung C.
• Application Number:
  US08/618,211
• Time in Patent Office: 924 Days
• Field of Search: 395/200.47, 395/200.48, 395/200.49, 395/200.57, 395/200.58, 395/200.79, 370/392, 370/393, 364/DIG. 1
• US Class Current: 709/227
• CPC Class Codes: H04L 61/2528 Translation at a proxy
• CPC Class Codes: H04L 61/255 Maintenance or indexing of mapping tables
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

An address reporting device receives a query for an address corresponding to a machine name of a machine on a first network, from a second network. The address reporting device accesses name servers so as to determine whether or not the address corresponding to the machine name designated in the query is an unauthorized address. If it is determined that the address corresponding to the machine name designated in the query is an unauthorized address, the address reporting device searches an address pair register table and/or an address mapping table stored in a router equipped with address translation function so as to specify an appropriate authorized address corresponding to the unauthorized address and prepares an address pair formed by the specified authorized address and the unauthorized address. The address pair is registered in the address pair register table. The address reporting device returns the authorized address forming the pair to the second network.

Claims

1. An address reporting method for returning, when a query requesting an address corresponding to a machine name of a machine on a first network provided with an authorized address and an unauthorized address is issued from a second network, the requested address to the second network,

said address reporting method comprising the steps of:

a) receiving a query for the address from the second network;

b) determining whether or not the address corresponding to the machine name designated in the query received in step a) is the unauthorized address;

c) preparing, when it is determined through step b) that the address corresponding to the machine name designated in the query is the unauthorized address, an address pair formed by the unauthorized address and the authorized address;

d) registering the address pair prepared in step c) in an address pair register table; and

e) returning the authorized address forming the address pair to the second network, when it is determined through step b) that the address corresponding to the machine name designated in the query is the unauthorized address.

6. The address reporting method as claimed in claim 1, further comprising the steps of:

l) adding data relating to an permitted survival period to information returned to the second network; and

m) deleting from the address pair register table the address pair that contains the authorized address returned to the second network after the permitted survival period has expired.

7. The address reporting method as claimed in claim 1, further comprising the steps of:

n) adding data relating to an permitted survival period to information returned to the second network; and

o) deleting from the address pair register table the address pair that contains the authorized address returned to the second network,

wherein

the permitted survival period is set to match a registration period during which the address pair can remain registered in the address pair register table.

2. An address reporting method for returning, when a query requesting an address corresponding to a machine name for a machine on a first network provided with a plurality of authorized addresses and a plurality of unauthorized addresses is issued from a second network, the requested address to the second network,

said address reporting method comprising the steps of:

a) receiving a query for the address from the second network;

b) determining whether or not the address corresponding to the machine name designated in the query received in step a) is one of the plurality of unauthorized addresses;

c) preparing, when it is determined through step b) that the address corresponding to the machine name designated in the query is the unauthorized address, an address pair formed by the unauthorized address and the one of the plurality of authorized addresses;

d) registering the address pair prepared in step c) in an address pair register table; and

e) returning the authorized address forming the address pair to the second network, when it is determined through step b) that the address corresponding to the machine name designated in the query is one of the plurality of unauthorized addresses.

3. The address reporting method as claimed in claim 2, wherein there is provided an address mapping table by which one of the plurality of authorized addresses can be identified by specifying one of the unauthorized addresses,

said address reporting method further comprising the step of f) reading, when it is determined through step b) that the address corresponding to the machine name designated in the query from the second network is one of the plurality of unauthorized addresses, one of the authorized addresses registered in the address mapping table, and

said address pair including the authorized address read through step f) being prepared through step c).

8. The address reporting method as claimed in claim 2, further comprising the steps of:

g) adding data relating to an permitted survival period to information returned to the second network; and

h) deleting from the address pair register table the address pair that contains the authorized address returned to the second network,

wherein

the permitted survival period is set such that it matches a registration period during which the address pair can remain registered in the address pair register table, and is in inverse proportion to the number of addresses pairs registered in the address pair register table.

4. An address reporting method for returning when a query requesting an address corresponding to a machine name for a machine on a first network provided with a plurality of authorized addresses and a plurality of unauthorized addresses is issued from a second network, the requested address to the second network,

said address reporting method comprising the steps of:

a) receiving a query for the address from the second network;

b) determining whether or not the address corresponding to the machine name designated in the query received in step a) is one of the plurality of unauthorized addresses;

c) preparing, when it is determined through step b) that the address corresponding to the machine name designated in the query is the unauthorized address, an address pair formed by the unauthorized address and the one of the plurality of authorized addresses;

d) registering the address pair prepared in step c) in an address pair register table;

e) returning the authorized address forming the address pair to the second network, when it is determined through step b) that the address corresponding to the machine name is designated in the query is one of the plurality of unauthorized addresses;

f) determining, when it is determined that the address corresponding to the machine name designated in the query is one of the plurality of unauthorized addresses, whether or not the address pair that contains the unauthorized address corresponding to the host name designated in the query is registered in the address pair register table;

g) reading, when it is determined through step g) that the address pair that contains the unauthorized address corresponding to the machine name designated in the query is registered in the address pair register table, the authorized address forming the address pair from the address pair register table;

h) specifying, when it is determined through step f) that the address pair that contains the unauthorized address corresponding to the machine name designated in the query is not registered in the address pair register table, one of the plurality of authorized addresses not registered in the address pair register table; and

i) registering an address pair formed by the unauthorized address corresponding to the machine name designated in the query and the authorized address specified through step h) in the address pair register table, wherein

when the authorized address is read from the address pair register table through step h), the authorized address read is returned to the second network in step e), and

when the authorized address is specified through step h), the specified address is returned to the second network in step e).

5. The address reporting method as claimed in claim 4, wherein there is provided an address mapping table by which one of the plurality of authorized addresses can be identified by specifying one of the unauthorized addresses,

the address mapping table being searched in step h) so as to specify one of the authorized addresses forming a pair with the unauthorized address corresponding to the machine name designated in the query from the second network, and

said address reporting method further comprising the step of j) reading the authorized address specified in step h) from the address mapping table.

9. An address reporting apparatus for returning, when a query for an address corresponding to a machine name of a machine on a first network is issued from a second network, the requested address to the second network, using authorized address storing means for storing an authorized address in the first network, said address reporting apparatus comprising:

unauthorized address storing means storing an unauthorized address in the first network;

receiving means receiving the query for the address from the second network;

address determining means determining whether the address corresponding to the machine name designated in the query received by the receiving means is the authorized address stored in the authorized address storing means or the unauthorized address stored in the unauthorized address storing means;

address pair preparing means preparing, when it is determined by the address determining means that the address corresponding to the machine designated in the query is the unauthorized address, the address pair formed by the unauthorized address and the authorized address;

address pair registering means storing the address pair prepared by the address pair preparing means in an address pair register table; and

address reporting means reporting, when it is determined by the address determining means that the address corresponding to the machine name designated in the query is the unauthorized address, the authorized address forming the address pair with the unauthorized address to the second network.

14. The address reporting apparatus as claimed in claim 9, further comprising:

permitted survival period data adding means adding data relating to an permitted survival period of information returned to the second network; and

address pair deleting means deleting the address pair that contains the authorized address returned to the second network from the address pair register table when the permitted survival period has expired.

15. The address reporting apparatus as claimed in claim 9, further comprising:

permitted survival period data adding means adding data relating to an permitted survival period to information returned to the second network; and

address pair deleting means deleting the address pair that contains the authorized address returned to the second network from the address pair register table,

wherein

the permitted survival period is set to match a registration period during which the address pair can remain registered in the address pair register table.

10. An address reporting apparatus for returning, when a query for an address corresponding to a machine name of a machine on a first network is issued from a second network, the requested address to the second network, using authorized address storing means for storing a plurality of authorized addresses in the first network, said address reporting apparatus comprising:

unauthorized address storing means storing a plurality of unauthorized addresses in the first network;

receiving means receiving the query for the address from the second network;

address determining means determining whether the address corresponding to the machine name designated in the query received by the receiving means is one of the plurality of authorized addresses stored in the authorized address storing means or one of the plurality of unauthorized addresses stored in the unauthorized address storing means;

address pair preparing means preparing, when it is determined by the address determining means that the address corresponding to the machine designated in the query is one of the plurality of unauthorized addresses, the address pair formed by the unauthorized address and one of the plurality of authorized addresses;

address pair registering means storing the address pair prepared by the address pair preparing means in an address pair register table; and

address reporting means reporting, when it is determined by the address determining means that the address corresponding to the machine name designated in the query is one of the plurality of unauthorized addresses, the authorized address forming the address pair with the unauthorized address to the second network.

11. The address reporting apparatus as claimed in claim 10, wherein there is provided an address mapping table by which one of the plurality of authorized addresses can be identified by specifying one of the unauthorized addresses,

said address reporting apparatus further comprising address mapping table reading means reading, when it is determined by the address determining means that the address corresponding to the machine name designated in the query from the second network is one of the plurality of unauthorized addresses, one of the authorized addresses registered in the address mapping table, and

the address pair preparing means preparing the address pair that contains the authorized address read by the address mapping table reading means.

16. The address reporting apparatus as claimed in claim 10, further comprising:

permitted survival period data adding means adding data relating to an permitted survival period to information returned to the second network; and

address pair deleting means deleting the address pair that contains the authorized address returned to the second network from the address pair register table,

wherein

the permitted survival period is set such that it matches a registration period during which the address pair can remain registered in the address pair register table, and is in inverse proportion to the number of addresses pairs registered in the address pair register table.

12. An address reporting apparatus for returning, when a query for an address corresponding to a machine name of a machine on a first network is issued from a second network, the requested address to the second network, using authorized address storing means for storing a plurality of authorized addresses in the first network, said address reporting apparatus comprising:

unauthorized address storing means storing a plurality of unauthorized addresses in the first network;

receiving means receiving the query for the address from the second network;

address determining means determining whether the address corresponding to the machine name designated in the query received by the receiving means is one of the plurality of authorized addresses stored in the authorized address storing means or one of plurality of unauthorized addresses stored in the unauthorized address storing means;

address pair preparing means preparing, when it is determined by the address determining means that the address corresponding to the machine designated in the query is one of the plurality of unauthorized addresses, the address pair formed by the unauthorized address and one of the plurality of authorized addresses;

address pair registering means storing the address pair prepared by the address pair preparing means in an address pair register table;

address reporting means reporting, when it is determined by the address determining means that the address corresponding to the machine name designated in the query is one of the plurality of unauthorized addresses, the authorized address forming the address pair with the unauthorized address to the second network;

registration determining means determining, when it is determined that the address corresponding to the machine name designated in the query is one of the plurality of unauthorized addresses, whether or not the address pair that contains the unauthorized address corresponding to the machine name designated in the query is registered in the address pair register table;

address pair register table reading means reading, when it is determined by the registration determining means that the address pair that contains the unauthorized address corresponding to the machine name designated in the query, the address pair register table; and

address specifying means specifying, when it is determined by the registration determining means that the address pair that contains the unauthorized address corresponding to the machine name designated in the query is not registered in the address pair register table, one of the authorized addresses from among the plurality of authorized addresses not registered in the address pair register table, wherein

the address pair registering means registers the address pair formed by the address corresponding to the machining name designated in the query and the authorized address specified by the address specifying means, in the address pair register table, and

the address reporting means returns, when the authorized address is read by the address pair register table reading means from the address pair register table, the authorized address read to the second network, or returns, when one of the authorized addresses is specified by the address specifying means, the specified authorized address to the second network.

13. The address reporting apparatus as claimed in claim 12, wherein there is provided an address mapping table by which one of the plurality of authorized addresses can be identified by specifying one of the unauthorized addresses, and the address specifying means searches the address mapping table so as to read therefrom one of the authorized addresses forming a pair with the unauthorized address corresponding to the machine name designated in the query from the second network.

17. An address reporting system for returning, when a query for an address corresponding to a machine name of a machine on a first network having an authorized address and an unauthorized address is issued from a second network communicable with the first network, the requested address to the second network, said address reporting system comprising:

authorized address storing means storing an authorized address;

unauthorized address storing means storing an unauthorized address;

receiving means receiving the query for the address from the second network;

address determining means determining whether the address corresponding to the machine name designated in the query received by the receiving means is the authorized address stored in the authorized address storing means or the unauthorized address stored in the unauthorized address storing means;

address pair preparing means preparing, when it is determined by the address determining means that the address corresponding to the machine designated in the query is the unauthorized address, the address pair formed by the unauthorized address and the authorized address;

address pair registering means storing the address pair prepared by the address pair preparing means in an address pair register table; and

address reporting means reporting, when it is determined by the address determining means that the address corresponding to the machine name designated in the query is the unauthorized address, the authorized address forming the address pair with the unauthorized address to the second network.

22. The address reporting system as claimed in claim 17, further comprising:

permitted survival period data adding means adding data relating to an permitted survival period of information returned to the second network; and

address pair deleting means deleting the address pair that contains the authorized address returned to the second network from the address pair register table when the permitted survival period has expired.

23. The address reporting system as claimed in claim 17, further comprising:

permitted survival period data adding means adding data relating to an permitted survival period to information returned to the second network; and

address pair deleting means deleting the address pair that contains the authorized address returned to the second network from the address pair register table,

wherein

the permitted survival period is set to match a registration period during which the address pair can remain registered in the address pair register table.

18. An address reporting system for returning, when a query for an address corresponding to a machine name of a machine on a first network having a plurality of authorized addresses and a plurality of unauthorized addresses is issued from a second network communicable with the first network, the requested address to the second network, said address reporting system comprising:

authorized address storing means storing the plurality of authorized addresses;

unauthorized address storing means storing the plurality of unauthorized addresses;

receiving means receiving the query for the address from the second network;

address determining means determining whether the address corresponding to the machine name designated in the query received by the receiving means is the authorized address stored in the authorized address storing means or the unauthorized address stored in the unauthorized address storing means;

address pair preparing means preparing, when it is determined by the address determining means that the address corresponding to the machine designated in the query is the unauthorized address, the address pair formed by the unauthorized address and the authorized address;

address pair registering means storing the address pair prepared by the address pair preparing means in an address pair register table; and

address reporting means reporting, when it is determined by the address determining means that the address corresponding to the machine name designated in the query is the unauthorized address, the authorized address forming the address pair with the unauthorized address to the second network.

19. The address reporting system as claimed in claim 18, wherein there is provided an address mapping table by which one of the plurality of authorized addresses can be identified by specifying one of the unauthorized addresses,

said address reporting system further comprising address mapping table reading means reading, when it is determined by the address determining means that the address corresponding to the machine name designated in the query from the second network is one of the plurality of unauthorized addresses, one of the authorized addresses registered in the address mapping table, and

the address pair preparing means preparing the address pair that contains the authorized address read by the address mapping table reading means.

24. The address reporting system as claimed in claim 18, further comprising:

permitted survival period data adding means adding data relating to an permitted survival period to information returned to the second network; and

address pair deleting means deleting the address pair that contains the authorized address returned to the second network from the address pair register table,

wherein

the permitted survival period is set such that it matches a registration period during which the address pair can remain registered in the address pair register table, and is in inverse proportion to the number of addresses pairs registered in the address pair register table.

20. An address reporting system for returning, when a query for an address corresponding to a machine name of a machine on a first network having a plurality of authorized addresses and a plurality of unauthorized addresses is issued from a second network communicable with the first network, the requested address to the second network, said address reporting system comprising:

authorized address storing means storing the plurality of authorized addresses;

unauthorized address storing means storing the plurality of unauthorized addresses;

receiving means receiving the query for the address from the second network;

address determining means determining whether the address corresponding to the machine name designated in the query received by the receiving means is the authorized address stored in the authorized address storing means or the unauthorized address stored in the unauthorized address storing means;

address pair preparing means preparing, when it is determined by the address determining means that the address corresponding to the machine designated in the query is the unauthorized address, the address pair formed by the unauthorized address and the authorized address;

address pair registering means storing the address pair prepared by the address pair preparing means in an address pair register table;

address reporting means reporting, when it is determined by the address determining means that the address corresponding to the machine name designated in the query is the unauthorized address, the authorized address forming the address pair with the unauthorized address to the second network;

registration determining means determining, when it is determined that the address corresponding to the machine name designated in the query is one of the plurality of unauthorized addresses, whether or not the address pair that contains the unauthorized address corresponding to the machine name designated in the query is registered in the address pair register table;

address pair register table reading means reading, when it is determined by the registration determining means that the address pair that contains the unauthorized address corresponding to the machine name designated in the query, the authorized address forming the address pair from the address pair register table; and

address specifying means specifying, when it is determined by the registration determining means that the address pair that contains the unauthorized address corresponding to the machine name designated in the query is not registered in the address pair register table, one of the authorized addresses from among the plurality of authorized addresses not registered in the address pair register table, wherein

the address pair registering means registers the address pair formed by the address corresponding to the machine name designated in the query and authorized address specified by the address specifying means, in the address pair register table, and

the address reporting means returns, when the authorized address is read by the address pair register table reading means from the address pair register table, the authorized address read to the second network, or returns, when one of the authorized addresses is specified by the address specifying means, the specified authorized address to the second network.

21. The address reporting system as claimed in claim 20, wherein there is provided an address mapping table by which one of the plurality of authorized addresses can be identified by specifying one of the unauthorized addresses, and the address specifying means searches the address mapping table so as to read therefrom one of the authorized addresses forming a pair with the unauthorized address corresponding to the machine name designated in the query from the second network.

25. An address reporting apparatus for returning, when a query for an address corresponding to a machine name of a machine on a first network is issued from a second network, the requested address to the second network, using an authorized address storing device for storing at least one authorized address in the first network, the address reporting apparatus comprising:

an address determining device determining whether the address corresponding to the machine name designated in the query is one of the at least one authorized addresses stored in the authorized address storing device or one of at least one unauthorized addresses stored in an unauthorized address storing device;

an address pair preparing device preparing, when it is determined by the address determining device that the address corresponding to the machine designated in the query is one of the at least one unauthorized addresses, the address pair formed by the unauthorized address and one of the at least one authorized addresses and storing the address pair in an address pair register table; and

an address reporting device reporting, when it is determined by the address determining device that the address corresponding to the machine name designated in the query is one of the at least one unauthorized addresses, the authorized address forming the address pair with the unauthorized address to the second network.