Cisco Technology, Inc.

Nagarani Chandika

Yiqun Cai

Ishan Wu

Ramana Mellacheruva

Adam James Sweeney

Premkumar Jonnala

Feng Zhu

Hugh Holbrook

Dehua Huang

Kyle Haight

Dan Mihai Florea

Bimohit Bawa

Access devices and methods according to the invention interconnect digital devices and a network. Setting a parameter associated with each input port of an access device specifies whether the device connected with that port is restricted or unrestricted. When a particular input port is restricted, packet detectors examine the packets received on that port. In some embodiments, an exception handler handles restricted packets from restricted devices in an advantageously flexible manner. In other embodiments, a controller receives a configuration command and sets the restriction parameters accordingly. The invention provides a simple, abstract, easy to use, and flexible tool for network management, configuration, and reconfiguration.

Network access device with restricted and unrestricted input ports

A DHCP proxy agent is provided to send on behalf of a static host a DHCP request so that an access layer security feature such as DHCP snooping/IPSG can be applied to the static host and/or in a mixed static IP and DHCP environment.

DHCP proxy for static host

A method and apparatus for a downstream router to inform an upstream router by use of packets of a new router command protocol that the upstream router is to forward multicast packets of a specified group to the downstream router. First the downstream router transmits a HELLO packet to upstream router to inform the upstream router that the downstream router is a multicast router implementing the invention. Then, in the event that the downstream router receives a packet from an end station requesting multicast packets of a particular group, in response the downstream router sends a JOIN packet to the upstream router. The JOIN packet requests that the upstream router forward the requested group multicast packets to the downstream router. When a multicast group packet arrives at the upstream router, the upstream router forwards the packet to those downstream routers requesting that group.

Multicast system for forwarding desired multicast packets in a computer network

A method and apparatus for a router to inform a Layerswitch by use of packets of a new router group port management protocol (RGMP) that the layerswitch is to forward multicast packets of a specified group to the router. First the router transmits a RGMP HELLO packet to the layerswitch to inform the switch that the router is a multicast router implementing the invention. Then, in the event that the router receives an IGMP packet from an end station requesting multicast packets of a particular group, in response the router sends an RGMP JOIN packet to the layerswitch. The RGMP JOIN packet requests that the layerswitch forward only multicast group packets, of the group whose group number is written into a field of the RGMP JOIN packet, to the router. Also, the router sends a prior art PIM JOIN packet to other multicast routers in order to be placed on the multicast distribution tree for that group. The layerswitch builds a forwarding table for multicast groups listing ports connected to routers having sent a RGMP JOIN for that group. When a multicast group packet arrives at the layerswitch, the switch uses the forwarding table to forward the packet only to those routers requesting that group.

Growing community of inventors

Sunnyvale, CA, United States of America

Nagarani Chandika