Virtual LAN

Abstract: A hub for a segmented virtual local area network with shared media access has at least one internal port for receiving and transmitting digital data messages within the hub and may have at least one external port for receiving and transmitting digital data messages external to the hub. The hub further includes a memory for storing virtual local area network (VLAN) designations for internal and external ports. The hub associates VLAN designations with at least one internal port, stores such VLAN designations in the memory, and associates the stored VLAN designations with messages transmitted from any of the ports to which the VLAN designation has been assigned. Additionally, the hub identifies VLAN designations associated with messages received by or within the hub and means and transmits to any of the internal ports only messages received within the hub and having associated with them a VLAN designation which matches the stored VLAN designation assigned to the port. The hub also has the ability to store media access control (MAC) addresses of internal ports and of end stations connected to internal or external ports and only send a message to a port when the destination address of the message is the MAC address of that port or of an end station known to be reachable through that port.

Abstract: Method and apparatus for establishing restricted broadcast groups in a switched network. The method assigns different virtual LAN identifiers (VLAN-IDs) to different subsets of associated end systems or access ports. Tables are maintained for mapping the VLAN-IDs with associated end systems and access ports. When a broadcast packet is received at a first switch, it is encapsulated with a VLAN header, including the VLAN-IDs, and sent out a multicast channel to all other switches in the network (domain). The original packet is sent out the other access ports of the receiving switch for the designated VLAN-IDs. The switches receiving the VLAN packet remove the header and send the original packet out access ports associated with the VLAN-IDs extracted from the header. The method provides a mechanism for forwarding broadcast packets of a protocol not supported by the switching mechanism, as well as multicast packets and unicast packets from undiscovered end systems.

Abstract: Methods and apparatus to communicatively couple virtual private networks to virtual machines within distributive computing networks are disclosed. A disclosed example method includes receiving a request to provision a virtual machine from a virtual private network, determining a host for the virtual machine within a distributive computing network, creating the virtual machine within the host, communicatively coupling the virtual machine to a virtual local area network switch within the distributive computing network, configuring a portion of a router to be communicatively coupled to the virtual machine via the virtual local area network switch by specifying an address space within the router associated with at least one of the virtual machine or the virtual private network communicatively coupled to the router, and communicatively coupling the portion of the router to the virtual private network.

Abstract: A system in which a single VLAN architecture spans multiple VLAN transport protocols and technologies, including a method and system in which multiple different VLANs may be combined in a single enterprise network. Each LAN-switch in the sytem identifies each frame with an identifier, and associates that identifier with particular VLAN identifiers for each type of VLAN technology. When a frame is bridged or routed from a first type of VLAN to a second type of VLAN, the first VLAN encapsulation is removed and the second VLAN encapsulation is added, with appropriate change in the VLAN identifier for the frame or packet. The identifier may also be implicit for the frame, such as when a particular set of sender's MAC addresses are identified with a particular VLAN. Individual VLANs, of whatever architecture, may be added, configured or reconfigured, modified, or deleted, using control tools associated with the multiple VLAN architecture system. Individual ports may be associated with particular VLANs, or may be designated "dynamic" so that frames or packets associated with those ports are associated with particular VLANs in response to source or destination addresses or other information.