Abstract: An example method for routing IPv6 link-local addresses in a network environment is provided and includes receiving a packet at a first switch from an attached first host in a virtual local area network (VLAN) associated with a virtual routing and forwarding (VRF) instance of a network environment, where the packet is destined to an Internet Protocol version 6 (IPv6) link-local address of a remote second host in the VLAN, and routing the packet at Layer 3 to a second switch, to which the second host is attached. In specific embodiments, the second switch routes the packet at Layer 3 to the second host if the VRF does not include duplicate IPv6 link-local addresses corresponding to the IPv6 link-local address of the second host; the second switch bridges the packet at Layer 2 to the second host if the VRF includes at least one duplicate IPv6 link-local address.

Abstract: Techniques are provided for sending address information of virtual machines to a physical switch. A migration of a virtual machine to a physical server is detected. The physical server obtains address information of the virtual machine, and upon obtaining the address information of the virtual machine, the physical server sends the address information to a first physical switch that is connected to the physical server.

Abstract: A method for optimizing within subnet communication in a network environment is provided and includes receiving, at a Top-Of-Rack (ToR) switch, an advertisement from an attached host belonging to a subnet of a network environment, seeking a Media Access Control (MAC) address of a remote host in the subnet, looking up a host information database in a control plane of the ToR switch, and responding to the advertisement with the MAC address of the remote host. If the MAC address is not found, the ToR switch may not respond to the advertisement. The method can further include receiving, at the ToR switch from a remote ToR switch in the subnet, a host information of the remote host in the subnet, including an IP address and the MAC address of the remote host, the Layer 2 broadcast domain it belongs to, and storing the host information in the host information database.

Abstract: In one embodiment, a method includes receiving from a server, flow data for a plurality of flows at a network device, the flow data comprising for each flow, a destination address and a time indicating when a last packet was processed for the flow at the server, updating a flow table at the network device, identifying one of the flows in the flow table as an inactive flow, and removing a route for the inactive flow from a forwarding information base at the network device. An apparatus and logic are also disclosed herein.

Abstract: In one embodiment, a method includes tracking at a network device in communication with a plurality of virtual machines, virtual machine movement based on a device identifier in a packet received from one of the virtual machines and storing location information for the virtual machine in a virtual machine move list at the network device. The location information from the virtual machine move list is inserted into a forwarding information base for use in optimized forwarding of packets destined for the virtual machine. An apparatus and logic are also disclosed herein.

Abstract: An example method is provided and includes receiving, at an ingress switch in a network, a packet from an attached host that is coupled to a destination host, where the packet includes an Internet Protocol version 6 (IPv6) address of a destination host, comparing the IPv6 address with a plurality of entries in a longest prefix match (LPM) table, in which each entry includes a value string and a corresponding mask string configured to detect a match for a specific combination of a segment prefix and a switch-id in the IPv6 address, identifying an egress switch from a matching entry in the LPM table, and forwarding the packet to the egress switch. The IPv6 address includes a combination of segment prefix and switch-id associated with the egress switch. The segment prefix corresponds to an identifier of a network segment, and the switch-id corresponds to an identifier of a switch in the network.

Abstract: An example method for routing IPv6 link-local addresses in a network environment is provided and includes receiving a packet at a first switch from an attached first host in a virtual local area network (VLAN) associated with a virtual routing and forwarding (VRF) instance of a network environment, where the packet is destined to an Internet Protocol version 6 (IPv6) link-local address of a remote second host in the VLAN, and routing the packet at Layer 3 to a second switch, to which the second host is attached. In specific embodiments, the second switch routes the packet at Layer 3 to the second host if the VRF does not include duplicate IPv6 link-local addresses corresponding to the IPv6 link-local address of the second host; the second switch bridges the packet at Layer 2 to the second host if the VRF includes at least one duplicate IPv6 link-local address.

Abstract: Techniques are provided for sending address information of virtual machines to a physical switch. A migration of a virtual machine to a physical server is detected. The physical server obtains address information of the virtual machine, and upon obtaining the address information of the virtual machine, the physical server sends the address information to a first physical switch that is connected to the physical server.

Abstract: An example method is provided and includes receiving, at an ingress switch in a network, a packet from an attached host that is coupled to a destination host, where the packet includes an Internet Protocol version 6 (IPv6) address of a destination host, comparing the IPv6 address with a plurality of entries in a longest prefix match (LPM) table, in which each entry includes a value string and a corresponding mask string configured to detect a match for a specific combination of a segment prefix and a switch-id in the IPv6 address, identifying an egress switch from a matching entry in the LPM table, and forwarding the packet to the egress switch. The IPv6 address includes a combination of segment prefix and switch-id associated with the egress switch. The segment prefix corresponds to an identifier of a network segment, and the switch-id corresponds to an identifier of a switch in the network.

Abstract: A method for optimizing within subnet communication in a network environment is provided and includes receiving, at a Top-Of-Rack (ToR) switch, an advertisement from an attached host belonging to a subnet of a network environment, seeking a Media Access Control (MAC) address of a remote host in the subnet, looking up a host information database in a control plane of the ToR switch, and responding to the advertisement with the MAC address of the remote host. If the MAC address is not found, the ToR switch may not respond to the advertisement. The method can further include receiving, at the ToR switch from a remote ToR switch in the subnet, a host information of the remote host in the subnet, including an IP address and the MAC address of the remote host, the Layer 2 broadcast domain it belongs to, and storing the host information in the host information database.

Abstract: In one embodiment, a method includes receiving from a server, flow data for a plurality of flows at a network device, the flow data comprising for each flow, a destination address and a time indicating when a last packet was processed for the flow at the server, updating a flow table at the network device, identifying one of the flows in the flow table as an inactive flow, and removing a route for the inactive flow from a forwarding information base at the network device. An apparatus and logic are also disclosed herein.

Abstract: In one embodiment, a method includes tracking at a network device in communication with a plurality of virtual machines, virtual machine movement based on a device identifier in a packet received from one of the virtual machines and storing location information for the virtual machine in a virtual machine move list at the network device. The location information from the virtual machine move list is inserted into a forwarding information base for use in optimized forwarding of packets destined for the virtual machine. An apparatus and logic are also disclosed herein.

Abstract: A technique that may be used to limit the amount of flooding that occurs for a particular virtual local area network (VLAN) in a data network. Limits are established for VLANs processed by an intermediate node. Each limit indicates a number of forwarding database entries that may be associated with a particular VLAN. If the number of entries in the forwarding database reaches the limit established for a particular VLAN, an action is taken which may include limiting the amount of flooding that occurs for that VLAN.