US5884024A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Secure DHCP server
Assignee: Oracle America Inc
•
Filing: 1996-12-09
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Granted: 1999-03-16
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Expires: 2016-12-09
Abstract
Abstract A preferred embodiment of the present invention includes a method and apparatus for allocating and using IP addresses in a network of client systems. More specifically, the present invention includes a DHCP server that leases IP addresses to the client systems. The DHCP server works in combination with a secure DHCP relay agent and a secure IP relay agent. Broadcast DHCPREQUEST messages are forwarded to the DHCP server by the secure DHCP relay agent. Before forwarding, the secure DHCP relay agent embeds in each DHCPREQUEST message. The trusted identifier is an unforgeable object specifically associated with the client system sending the DHCPREQUEST message. When the DHCP server receives a DHCPREQUEST message, the DHCP server extracts the trusted identifier. The trusted identifier is then used by the DHCP server to prevent client systems from accessing the IP address leases of other client systems. The DHCP server also counts the number of IP addresses leases assigned to each trusted identifier. In this way, each client system is prevented from leasing more than a predetermined number of IP addresses. Unicast DHCPREQUEST messages received by the DHCP server include a source address that corresponds to the client system sending the unicast DHCPREQUEST message. The validity of the source address is ensured by the secure IP relay agent. The DHCP server uses the source address to prevent client systems from accessing the IP address leases of other client systems.
Inventors
- 👤 Swee B. Lim
- 👤 Sanjay R. Radia
- 👤 Thomas K. Wong
- 👤 Panagiotis Tsirigotis
- 👤 Robert J. Goedman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 06:54
CPC Classifications
H; H04; H04L; H04L63/00; H04L63/12; H04L63/126; H04L61/00; H04L61/50; H04L61/5007; H04L61/5014; H04L61/5053
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
97 words
A method for allocating an IP address that comprises the steps, performed by a server system, of: receiving a message from a client system, the message requesting allocation of an IP address, the message including a trusted identifier with the trusted identifier being an object that cannot be forged by the client system; extracting the trusted identifier from the message; counting the number of IP addresses allocated to the trusted identifier; and allocating an IP address for the client system if the number of IP addresses allocated to the trusted identifier is less than a predetermined limit.
Claim 2
Independent Claim
97 words
A method for allocating an IP address that comprises the steps, performed by a server system, of: receiving a message from a client system, the message requesting allocation of an IP address, the message including a trusted identifier with the trusted identifier being an object that cannot be forged by the client system; extracting the trusted identifier from the message; counting the number of IP addresses allocated to the trusted identifier; and allocating an IP address for the client system if the number of IP addresses allocated to the trusted identifier is less than a predetermined limit.
Claim 3
Dependent Claim
15 words
A method as recited in claim 1 wherein the message is a broadcast DHCPREQUEST message.
Claim 4
Independent Claim
107 words
A method for allocating an IP address that comprises the steps, performed by a server system, of: receiving a message from a client system, the message requesting allocation of an IP address, the message including a trusted identifier with the trusted identifier being an object that cannot be forged by the client system; forming a lease identifier using the trusted identifier included in the message; determining if the lease identifier has an associated IP address lease; and allocating, if the lease identifier has an associated IP address lease, an IP address for the client system in accordance with the IP address lease associated with the lease identifier.
Claim 5
Independent Claim
107 words
A method for allocating an IP address that comprises the steps, performed by a server system, of: receiving a message from a client system, the message requesting allocation of an IP address, the message including a trusted identifier with the trusted identifier being an object that cannot be forged by the client system; forming a lease identifier using the trusted identifier included in the message; determining if the lease identifier has an associated IP address lease; and allocating, if the lease identifier has an associated IP address lease, an IP address for the client system in accordance with the IP address lease associated with the lease identifier.
Claim 6
Dependent Claim
15 words
A method as recited in claim 3 wherein the message is a broadcast DHCPREQUEST message.
Claim 7
Dependent Claim
32 words
A method as recited in claim 3 wherein the message includes a lease identification cookie and wherein the lease identifier is formed by combining the trusted identifier and the lease identification cookie.
Claim 8
Independent Claim
85 words
A method for allocating an IP address that comprises the steps, performed by a server system, of: receiving a message from a client system, the message requesting allocation of an IP address, the message including a source address with the validity of the source address being ensured by the secure relay agent; extracting the source address from the message; retrieving an IP address lease associated with the source address; and allocating an IP address for the client system in accordance with the IP address lease.
Claim 9
Independent Claim
85 words
A method for allocating an IP address that comprises the steps, performed by a server system, of: receiving a message from a client system, the message requesting allocation of an IP address, the message including a source address with the validity of the source address being ensured by the secure relay agent; extracting the source address from the message; retrieving an IP address lease associated with the source address; and allocating an IP address for the client system in accordance with the IP address lease.
Claim 10
Dependent Claim
15 words
A method as recited in claim 6 wherein the message is a unicast DHCPREQUEST message.
Claim 11
Dependent Claim
182 words
A computer program product including: a computer usable medium having computer readable code embodied therein for allocating IP addresses in a computer network that includes one or more client systems, each client system having an associated trusted identifier with the trusted identifier being an object that cannot be forged by the client system, the computer program product comprising: first computer readable program code devices configured to cause a computer system to receive a message from a client system, the message requesting allocation of an IP address, the message including the trusted identifier of the client system sending the message; second computer readable program code devices configured to cause a computer system to extract the trusted identifier from the message; third computer readable program code devices configured to cause a computer system to count the number of IP addresses allocated to the trusted identifier; and fourth computer readable program code devices configured to cause a computer system to allocate an IP address for the client system if the number of IP addresses allocated to the trusted identifier is less than a predetermined limit.
Claim 12
Dependent Claim
182 words
A computer program product including: a computer usable medium having computer readable code embodied therein for allocating IP addresses in a computer network that includes one or more client systems, each client system having an associated trusted identifier with the trusted identifier being an object that cannot be forged by the client system, the computer program product comprising: first computer readable program code devices configured to cause a computer system to receive a message from a client system, the message requesting allocation of an IP address, the message including the trusted identifier of the client system sending the message; second computer readable program code devices configured to cause a computer system to extract the trusted identifier from the message; third computer readable program code devices configured to cause a computer system to count the number of IP addresses allocated to the trusted identifier; and fourth computer readable program code devices configured to cause a computer system to allocate an IP address for the client system if the number of IP addresses allocated to the trusted identifier is less than a predetermined limit.
Claim 13
Dependent Claim
17 words
A computer program product as recited in claim 8 wherein the message is a broadcast DHCPREQUEST message.
Claim 14
Dependent Claim
200 words
A computer program product including: a computer usable medium having computer readable code embodied therein for allocating IP addresses in a computer network that includes one or more client systems, each client system having an associated trusted identifier with the trusted identifier being an object that cannot be forged by the client system, the computer program product comprising: first computer readable program code devices configured to cause a computer system to receive a message from a client system, the message requesting allocation of an IP address, the message including a trusted identifier with the trusted identifier being an object that cannot be forged by the client system; second computer readable program code devices configured to cause a computer system to form a lease identifier using the trusted identifier included in the message; third computer readable program code devices configured to cause a computer system to determine if the lease identifier has an associated IP address lease; and fourth computer readable program code devices configured to cause a computer system to allocate, if the lease identifier has an associated IP address lease, an IP address for the client system in accordance with the IP address lease associated with the lease identifier.
Claim 15
Dependent Claim
200 words
A computer program product including: a computer usable medium having computer readable code embodied therein for allocating IP addresses in a computer network that includes one or more client systems, each client system having an associated trusted identifier with the trusted identifier being an object that cannot be forged by the client system, the computer program product comprising: first computer readable program code devices configured to cause a computer system to receive a message from a client system, the message requesting allocation of an IP address, the message including a trusted identifier with the trusted identifier being an object that cannot be forged by the client system; second computer readable program code devices configured to cause a computer system to form a lease identifier using the trusted identifier included in the message; third computer readable program code devices configured to cause a computer system to determine if the lease identifier has an associated IP address lease; and fourth computer readable program code devices configured to cause a computer system to allocate, if the lease identifier has an associated IP address lease, an IP address for the client system in accordance with the IP address lease associated with the lease identifier.
Claim 16
Dependent Claim
17 words
A computer program product as recited in claim 10 wherein the message is a broadcast DHCPREQUEST message.
Claim 17
Dependent Claim
34 words
A computer program product as recited in claim 10 wherein the message includes a lease identification cookie and wherein the lease identifier is formed by combining the trusted identifier and the lease identification cookie.
Claim 18
Dependent Claim
178 words
A computer program product including: a computer usable medium having computer readable code embodied therein for allocating lP addresses in a computer network that includes one or more client systems, each client system having an associated trusted identifier with the trusted identifier being an object that cannot be forged by the client system, the computer program product comprising: first computer readable program code devices configured to cause a computer system to receive a message from a client system, the message requesting allocation of an IP address, the message including a source address with the validity of the source address being ensured by the secure relay agent; second computer readable program code devices configured to cause a computer system to extract the source address from the message; third computer readable program code devices configured to cause a computer system to retrieve an IP address lease associated with the source address; and fourth computer readable program code devices configured to cause a computer system to allocate an IP address for the client system in accordance with the IP address lease.
Claim 19
Dependent Claim
178 words
A computer program product including: a computer usable medium having computer readable code embodied therein for allocating lP addresses in a computer network that includes one or more client systems, each client system having an associated trusted identifier with the trusted identifier being an object that cannot be forged by the client system, the computer program product comprising: first computer readable program code devices configured to cause a computer system to receive a message from a client system, the message requesting allocation of an IP address, the message including a source address with the validity of the source address being ensured by the secure relay agent; second computer readable program code devices configured to cause a computer system to extract the source address from the message; third computer readable program code devices configured to cause a computer system to retrieve an IP address lease associated with the source address; and fourth computer readable program code devices configured to cause a computer system to allocate an IP address for the client system in accordance with the IP address lease.
Claim 20
Dependent Claim
17 words
A computer program product as recited in claim 13 wherein the message is a unicast DHCPREQUEST message.
Claim 21
Independent Claim
157 words
An apparatus for allocating IP addresses in a computer network that includes one or more client systems, each client system having an associated trusted identifier with the trusted identifier being an object that cannot be forged by the client system, the computer program product apparatus: a first portion configured to allow a computer system to receive a message from a client system, the message requesting allocation of an IP address, the message including the trusted identifier of the client system sending the message; a second portion configured to cause a computer system to extract the trusted identifier from the message; a third portion configured to cause a computer system to count the number of IP addresses allocated to the trusted identifier; and a fourth portion configured to cause a computer system to allocate an IP address for the client system if the number of IP addresses allocated to the trusted identifier is less than a predetermined limit.
Claim 22
Independent Claim
157 words
An apparatus for allocating IP addresses in a computer network that includes one or more client systems, each client system having an associated trusted identifier with the trusted identifier being an object that cannot be forged by the client system, the computer program product apparatus: a first portion configured to allow a computer system to receive a message from a client system, the message requesting allocation of an IP address, the message including the trusted identifier of the client system sending the message; a second portion configured to cause a computer system to extract the trusted identifier from the message; a third portion configured to cause a computer system to count the number of IP addresses allocated to the trusted identifier; and a fourth portion configured to cause a computer system to allocate an IP address for the client system if the number of IP addresses allocated to the trusted identifier is less than a predetermined limit.
Claim 23
Dependent Claim
15 words
An apparatus as recited in claim 15 wherein the message is a broadcast DHCPREQUEST message.
Claim 24
Independent Claim
175 words
An apparatus for allocating IP addresses in a computer network that includes one or more client systems, each client system having an associated trusted identifier with the trusted identifier being an object that cannot be forged by the client system, the computer program product apparatus: a first portion configured to allow a computer system to receive a message from a client system, the message requesting allocation of an IP address, the message including a trusted identifier with the trusted identifier being an object that cannot be forged by the client system; a second portion configured to cause a computer system to form a lease identifier using the trusted identifier included in the message; a third portion configured to cause a computer system to determine if the lease identifier has an associated IP address lease; and a fourth portion configured to cause a computer system to allocate, if the lease identifier has an associated IP address lease, an IP address for the client system in accordance with the IP address lease associated with the lease identifier.
Claim 25
Independent Claim
175 words
An apparatus for allocating IP addresses in a computer network that includes one or more client systems, each client system having an associated trusted identifier with the trusted identifier being an object that cannot be forged by the client system, the computer program product apparatus: a first portion configured to allow a computer system to receive a message from a client system, the message requesting allocation of an IP address, the message including a trusted identifier with the trusted identifier being an object that cannot be forged by the client system; a second portion configured to cause a computer system to form a lease identifier using the trusted identifier included in the message; a third portion configured to cause a computer system to determine if the lease identifier has an associated IP address lease; and a fourth portion configured to cause a computer system to allocate, if the lease identifier has an associated IP address lease, an IP address for the client system in accordance with the IP address lease associated with the lease identifier.
Claim 26
Dependent Claim
15 words
An apparatus as recited in claim 17 wherein the message is a broadcast DHCPREQUEST message.
Claim 27
Dependent Claim
32 words
An apparatus as recited in claim 17 wherein the message includes a lease identification cookie and wherein the lease identifier is formed by combining the trusted identifier and the lease identification cookie.
Claim 28
Independent Claim
125 words
An apparatus for allocating IP addresses in a computer network that includes one or more client systems: a first portion configured to allow a computer system to receive a message from a client system, the message requesting allocation of an IP address, the message including a source address with the validity of the source address being ensured by the secure relay agent; a second portion configured to cause a computer system to extract the source address from the message; a third portion configured to cause a computer system to retrieve an IP address lease associated with the source address; and a fourth portion configured to cause a computer system to allocate an IP address for the client system in accordance with the IP address lease.
Claim 29
Independent Claim
125 words
An apparatus for allocating IP addresses in a computer network that includes one or more client systems: a first portion configured to allow a computer system to receive a message from a client system, the message requesting allocation of an IP address, the message including a source address with the validity of the source address being ensured by the secure relay agent; a second portion configured to cause a computer system to extract the source address from the message; a third portion configured to cause a computer system to retrieve an IP address lease associated with the source address; and a fourth portion configured to cause a computer system to allocate an IP address for the client system in accordance with the IP address lease.
Claim 30
Dependent Claim
15 words
An apparatus as recited in claim 20 wherein the message is a unicast DHCPREQUEST message.
References Cited (Backward Citations)
US5598536A
Cited
US5684951A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-03-15 | 2002-09-14 | 2003-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-03-15 | 2006-09-14 | 2007-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-03-15 | 2010-09-14 | 2011-03-16 | $7700.00 | Window Closed / Lapsed |