Secure DHCP server

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.

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.

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.

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.

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.

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.

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.

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.