Patent US4930159A successfully refreshed from Google Patents.
US4930159A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Netbios name authentication
Assignee: International Business Machines Corp
•
Filing: 1989-01-18
•
Granted: 1990-05-29
•
Expires: 2009-01-18
Abstract
Abstract A method insures the NETBIOS names are not illegally used on a local area network. The NETBIOS protocols use a naming system that allows any station to claim a name or set of names that are not already in use. This potentially allows any user to "masquerade" as another user, or service machine, by claiming the name when the real user is not connected to the network. This method detects these attempted masquerades, disconnects the offending station from the network, and logs information about the attempt.
Inventors
- 👤 Jeffrey K. Kravitz
- 👤 Charles C. Palmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:29
CPC Classifications
H; H04; H04L; H04L41/00; H04L41/28; H04L12/00; H04L12/28; H04L12/42; H04L12/427; H04L12/433; H04L41/26; H04L63/00; H04L63/10
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
69 words
A method for preventing unauthorized workstations from being serviced on a local area network comprising the steps of: monitoring all broadcast messages on the network to detect name-query messages from workstations attempting to claim names; decoding a data frame in a name-query message to obtain a requested name and a unique adapter address of a requesting workstation; and verifying that a requested name matches a previously assigned adapter address.
Claim 2
Dependent Claim
75 words
The method according to claim 1, used to prevent the use of reserved names, further comprising the steps of: in the event that a requested name does not match a previously assigned adapter address, constructing a special frame that instructs an offending workstation to remove itself from the network, for networks supporting such a frame, or that informs the offending workstation the name is already in use; and transmitting said special frame on the network.
Claim 3
Dependent Claim
29 words
The method according to claim 2 further comprising the step of logging information about an attempt to claim a name that does not match a previously assigned adapter address.
Claim 4
Independent Claim
133 words
A method for preventing unauthorized use of reserved names in a local area network comprising the steps of: providing a name/address table in an authentication server attached to said network; monitoring at said authentication server all broadcast messages on the network to detect name-query messages from workstations attempting to claim names; comparing a requested name in a name-query message with names in said name/address table, and if no match is found, continuing to monitor said broadcast messages; if a name match is found in said name/address table, comparing an address accompanying the requested name with addresses in said name/address table, and if a match is found, continuing to monitor said broadcast messages; and if no address match is found in said name/address table, preventing an offending workstation from being recognized on the network.
Claim 5
Dependent Claim
51 words
The method according to claim 4 wherein said network supports a disconnect frame and said step of preventing is performed by the steps of: constructing a disconnect frame that instructs the offending workstation to remove itself from the network; and transmitting on said network by said authentication server said disconnect frame.
Claim 6
Dependent Claim
45 words
The method according to claim 4 wherein said step of preventing is performed by the steps of: constructing a special frame that informs the offending workstation that the name is already in use; and transmitting on said network by said authentication server said special frame.
Claim 7
Dependent Claim
29 words
The method according to claim 4 further comprising the step of logging information about an attempt to claim a name that does not match a previously assigned adapter address.
Claim 8
Dependent Claim
36 words
The method according to claim 4 further comprising the step of generating an error indication at said authentication server to indicate an attempt to claim a name that does not match a previously assigned adapter address.
Claim 9
Dependent Claim
45 words
The method according to claim 4 further comprising the steps of: logging information about an attempt to claim a name that does not match a previously assigned adapter address; and generating an error indication at said authentication server to provide an indication of said attempt.
Claim 10
Independent Claim
72 words
A system for preventing unauthorized workstations from being serviced on a local area network comprising: means for monitoring all broadcast messages on the network to detect name-query messages from workstations attempting to claim names; means for decoding a data frame in a name-query message to obtain a requested name and a unique adapter address of a requesting workstation; and means for verifying that a requested name matches a previously assigned adapter address.
Claim 11
Dependent Claim
79 words
The system according to claim 10, further comprising means for preventing the use of reserved names, comprising: means for constructing a special frame that instructs an offending workstation to remove itself from the network, for networks supporting such a frame, or informs the offending workstation the name is already in use, for other networks, in the event that a requested name does not match a previously assigned adapter address; and means for transmitting said special frame on the network.
Claim 12
Dependent Claim
28 words
The system according to claim 11 further comprising means for logging information about an attempt to claim a name that does not match a previously assigned adapter address.
Claim 13
Independent Claim
143 words
A system for preventing unauthorized use of reserved names in a local area network comprising: an authentication server attached to said network; a name/address table in said authentication server; means, at said authentication server, for monitoring all broadcast messages on the network to detect name-query messages from workstations attempting to claim names; means for comparing a requested name in a name-query message with names in said name/address table, and if no match is found, continuing to monitor said broadcast messages; means, if a name match is found in said name/address table, for comparing an address accompanying the requested name with addresses in said name/address table, and means, if such a match is found, for continuing to monitor said broadcast messages; and means, if no address match is found in said name/address table, for preventing an offending workstation from being recognized on the network.
Claim 14
Dependent Claim
49 words
The system according to claim 13 wherein said network supports a disconnect frame and said preventing means comprises: means for constructing a disconnect frame that instructs the offending workstation to remove itself from the network; and means for transmitting on said network by said authentication server said disconnect frame.
Claim 15
Dependent Claim
43 words
The system according to claim 13 wherein said preventing means comprises: means for constructing a special frame that informs the offending workstation that the name is already in use; and means for transmitting on said network by said authentication server said special frame.
Claim 16
Dependent Claim
28 words
The system according to claim 13 further comprising means for logging information about an attempt to claim a name that does not match a previously assigned adapter address.
Claim 17
Dependent Claim
35 words
The system according to claim 13 further comprising means for generating an error indication at said authentication server to indicate an attempt to claim a name that does not match a previously assigned adapter address.
Claim 18
Dependent Claim
46 words
The system according to claim 13 further comprising: means for logging information about an attempt to claim a name that does not match a previously assigned adapter address; and means for generating an error indication at said authentication server to provide an indication of said attempt.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-28 | 1993-11-27 | 1994-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-28 | 1997-11-27 | 1998-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-28 | 2001-11-27 | 2002-05-29 | $7700.00 | Window Closed / Lapsed |