Foundry Networks, Inc.

Brocade Communications Systems, Inc.

Ronald W Szeto

Rajkumar Ramniranjan Jalan

Philip Kwan

David Chun Ying Cheung

Nitin Jain

Ravindran Suresh

Raymond Wai-Kit Kwong

Sridhar J Devarapalli

David Chun-Ying Cheung

Each service in a computer network may have a connection rate limit. The number of new connections per time period may be limited by using a series of rules. In a specific embodiment of the present invention, a counter is increased each time a server is selected to handle a connection request. For each service, connections coming in are tracked. Therefore, the source of connection-request packets need not be examined. Only the destination service is important. This saves significant time in the examination of the incoming requests. Each service may have its own set of rules to best handle the new traffic for its particular situation. For server load balancing, a reset may be sent to the source address of the new connection request. For transparent cache switching, the connection request may be forwarded to the Internet.

Connection rate limiting for server load balancing and transparent cache switching

A system and method that provides for protection of a CPU of a router, by establishing a management port on a router. Hosts which are connected to a non-management ports of the router are denied access to management functions of a CPU of the router. The system and method can utilize an application specific integrated circuit, in conjunction with a CAM-ACL, which analyzes data packets received on the ports of router, and the ASIC operates to drop data packets which are directed to the CPU of the router. This system and method operates to filter data packets which may be generated in attempts to hack in to control functions of a network device, and the operation does not require that the CPU analyze all received data packets in connection with determining access to the control functions of the router.

System and method for protecting CPU against remote access attacks

Transaction rate limiting is provided to monitor new connections. If the number of new connections requested by a particular client exceeds a predetermined threshold value, then the client may be frozen out for a configured period of time. By denying access for the configured period of time, the client is prevented from monopolizing a particular client. Additionally, if the client does have malicious intent, a denial of service attack may be thwarted. The denial of service may be accomplished without alerting the client. This prevents a malicious client from regrouping and attempting an assault via a different mechanism.

Transaction rate limiting

A system and method that provides for using source IP addresses and MAC addresses in a network to provide security against attempts by users of the network to use false source IP addresses in data packets. The system and method provide for analyzing MAC addresses and source IP addresses at the datalink (layer 2) level, and to use the information derived from such analysis to block access through a port where a host device is using a false, or spoofed, source IP address in transmitted data packets. Further, the system and method provide for validating initially learned source IP addresses, and for determining whether the number of unsuccessful attempts to validate new source IP addresses exceeds a threshold level, and where the number does exceed the threshold number the system and method can provide for operation in a possible attack mode.

System and method for source IP anti-spoofing security

Each service in a computer network may have a connection rate limit. The number of new connections per time period may be limited by using a series of rules. In a specific embodiment of the present invention, a counter is increased each time a server is selected to handle a connection request. For each service, connections coming in are tracked. Therefore, the source of connection-request packets need not be examined. Only the destination service is important. This saves significant time in the examination of the incoming requests. Each service may have its own set of rules to best handle the new traffic for its particular situation.

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Pleasanton, CA, United States of America

Ronald W Szeto