Abstract: An information handling system is provided. The information handling system includes a first hypervisor running on a first server and a second hypervisor running on a second server. The first hypervisor manages a first virtual switch and has an overlay forwarding table in memory supporting at least one virtual machine, while the second hypervisor manages a second virtual switch and also has the overlay forwarding table in memory and supports at least one other VM. The information handling system further includes a plurality of gateway devices coupled to the hypervisors. The gateway devices share a floating address and are configured to export a host route, associated with the address, into a corresponding entry in an underlay routing table to redirect network traffic from a first gateway device to a second gateway device.

Abstract: A system and method for efficiently handling mobility events includes detecting a mobility event associated with a movement of a mobile unit from a first subnet to a second subnet, forming one or more first flow control messages for updating routing information associated with the mobility event, transmitting the one or more first flow control messages to a core router, forming one or more second flow control messages for disabling layer 2 learning, transmitting the one or more second flow control messages to one or more network switching devices in the first subnet, forming one or more third flow control messages including layer 2 switching instructions for directing network traffic to the mobile unit in the second subnet, and transmitting the one or more third flow control messages.

Abstract: Techniques are described which facilitate multi-destination forwarding in a Layer 2 Multipath (L2MP) network which includes an emulated switch. The emulated switch may correspond to two or more underlying peer link switches in the L2MP network, in which each of the peer link switches is linked to a Classical Ethernet (CE) switch over a virtual port channel (vPC). Traffic received by one of the peer link switches over the vPC is automatically forwarded to the other peer link switch (or switches). Multi-destination frames originating from the L2MP network addressed to hosts within the CE network are sent over only one of the peer link switches.

Abstract: A method and apparatus is disclosed for providing gateway anycast virtual MAC reachability in extended subnets. When an extended L2 subnet spans more than one geographical location, it is desirable that the gateway MAC addresses learned in each location be the same across all IP hosts. Accordingly, the gateway MAC address may be preserved (i.e., programmed) in more than one port on a bridge, such as both a local port and a LAN extension port. The bridge may forward traffic having the anycast MAC address to the closest instance of the MAC address, rather than replicating the traffic to the multiple ports on which the anycast MAC address is programmed. If the gateway reachable on the local port goes down, the frame may be forwarded to the local gateway in the second layer 2 subnet over the LAN extension port.

Abstract: In one embodiment, a first switch is located at a first border between first networks that utilize a STP to detect and break loops and second networks. The first switch is interconnected via the first networks with a second switch located at a second border between the first networks and the second networks. The first switch detects, via a protocol other than STP, addition of a link in the second networks that provides a new path across the second networks between the first switch and the second switch. The first switch blocks data packets from traversing through one or more network boundary ports of the first switch coupled to the first networks, while allowing STP BPDUs to traverse through the one or more network boundary ports, for a period of time sufficient for the first networks to discover the new path using STP.

Abstract: A first switch of a first network may receive a second set of information including routing identifiers associated with a second network, wherein the first switch of the first network is connected to a second switch of the second network. The first switch of the first network may transmit a first set of information including routing identifiers associated with the first network. The first switch may determine whether a conflict exists between the second set of information and the first set of information. A conflicting one of the routing identifiers associated with the first or second network may be transitioned to a non-conflicting routing identifier according to the determination of whether a conflict exists between the first set of information and the second set of information.

Abstract: In one embodiment, a method includes receiving information on layer 2 topologies at a network device in a core network, mapping one or more Virtual Local Area Networks (VLANs) to the layer 2 topologies to provide differentiated services in said layer 2 topologies, defining multiple paths for each of the layer 2 topologies, and forwarding a packet received at the network device on one of the multiple paths. An apparatus and logic for providing differentiated services in layer 2 topologies is also disclosed.

Abstract: In an embodiment, a method comprises: detecting a change in a multiple-switch configuration in a data communications network comprising a plurality of packet data switches configured as roots of multicast trees. In response to detecting that the multiple-switch configuration has changed, a first value, a second value and a third value representing limits on a number of multicast trees supported in the network and prioritization of the switches are retrieved. The method further comprises determining a type of the multiple-switch configuration change. In response to determining that the type indicates that a first switch was added to the multiple-switch configuration, using at least the first, second and third values, it is determined whether to configure the first switch as a first root in the multiple-switch configuration. The method is performed by one or more computing devices.

Abstract: A method is provided that includes configuring a first network element as a peer to a second network element. The first network element and the second network element are configured to execute a spanning-tree protocol (STP) in a network environment. The method may also include configuring a priority characteristic to be a same value for the first network element and the second network element such that both operate as root network elements for other network elements in the network environment.

Abstract: Embodiments described herein achieve proxy FHRP for anycast routing services through the coordination of L2MP edge switches to allow load balancing for the use of routing services. Such embodiments may avoid duplicity and coordinate control planes between the edge switches to present a proxy interface to the rest of the network for the routing services. As such, multipathing and load-balancing for efficient use of crucial services may be provided for client nodes inside the network.

Abstract: Techniques are provided for two peer edge switches in an edge switch cluster of a first data center site to actively provide traffic flow redundancy in an active-active configuration and provide multi-homing support over an overlay transport virtualization (OTV) protocol. Information is stored indicating a media access control (MAC) address of at least one endpoint device at the first site. An edge switch in the edge switch cluster at the first site sends via an OTV protocol a Layer-3 message that is configured to advertise the MAC address of the at least one endpoint at the first site to enable at least one edge switch at a second site to perform multipath routing to the endpoint device at the first site based on each of the edge switches in the edge switch cluster at the first site.

Abstract: Embodiments herein achieve proxy FHRP for anycast routing services through the coordination of L2MP edge switches to allow load balancing for the use of routing services. Such embodiments may avoid duplicity and coordinate control planes between the edge switches to present a proxy interface to the rest of the network for the routing services. As such, multipathing and load-balancing for efficient use of crucial services may be provided for client nodes inside the network.

Abstract: An example method is provided and can include initiating a probe session at a source network element; identifying multiple paths from the source network element to a destination network element in a network; transmitting packets from the source network element along the multiple paths; compiling a list of network characteristics associated with the multiple paths; and selecting a particular one of the multiple paths for packet routing based on the network characteristics.

Abstract: A method measures a resident delay for each port in a node in a network and a peer delay between each pair of neighbor nodes in the network. From these resident delays and peer delays, latency between each pair of neighbor nodes in the network is determined. The method includes weighting a route for a data packet going through the nodes in the network using the determined latencies. Each node includes a switch having switchable connections and is configured by a controller to send probe packets from an output port to a port in a neighbor node. The packet may include a time stamp and an identifier.

Abstract: An example method is provided and includes receiving a data message from a first virtual local area network; determining at an edge switch-router of a Layer-2 network whether the message should be routed; and routing the message in the Layer-2 network at the edge switch-router if the message should be routed. The method also includes switching the message at the edge switch-router if the message should not be routed.

Abstract: Techniques are provided to enable a switch in a layer-2 multipath network to determine connectivity of a path to a destination switch. At a source switch, user flow parameters are determined for user flow packets to be transported in the layer-2 multipath network to a destination switch. The sourced switch determines a number of hops from it to the destination switch based on the user flow parameters. Timestamping is activated for time-to-live expiry packets received at the source switch and for time-to-live expiry packets received at the destination switch. One or more probe packets having user flow parameters matching the user flow parameters of user flow packets are generated so that the probe packets use the same path taken by the user flow packets between the source switch and the destination switch. In addition, a time-to-live value corresponding to the number of hops from the source switch to the destination switch is included in a hop count field of the one or more probe packets.

Abstract: Methods and apparatus for generating different hash values in an effort to achieve better load balancing among various paths in a data center environment, such as Data Center Ethernet (DCE) with Layer 2 Multipathing (L2MP), supporting equal-cost multipath (ECMP) routing are provided. In this manner, the data center environment may attain better network utilization for high-performance computing (HPC), storage area network (SAN), and/or local area network (LAN) traffic.

Abstract: An example method is provided and includes a multicast data message from a data source, the message in a first virtual local area network and being associated with a multicast group. The method also includes calculating a hash value based on the virtual local area network, the data source, and the multicast group, determining a port for a designated router in a Layer-2 network based on the hash value, and switching the multicast data message to the port that was determined.

Abstract: A solution is provided wherein the interfaces between multiple chassis (e.g., edge switches) in a network of layer 2 devices and a spanning tree device are treated as a single emulated switch. This emulated switch effectively enables two different views to the two different sides. Thus, frames from the network of layer 2 switches destined to any port of the emulated switch may take any of the links (through any of the physical switches), thereby enabling effective load-balancing for frames traveling from the layer 2 network side into the spanning tree device. Meanwhile the spanning tree device does not recognize an illegal loop in its connection to two different edge switches as it views the two links as a single logical EtherChannel.

Abstract: In one embodiment, a method includes configuring a first network device for operation in a first logical group with a second network device, receiving information from other network devices configured for operation in a second logical group, the information uniquely identifying each of the other network devices within the second logical group, and assigning a priority to each link connecting the first network device to the second logical group network devices. A portion of the links are selected as active links based on the link priorities and the link priorities are assigned such that a balance of active links is maintained across the second logical group network devices. An apparatus for maintaining a balance of active links across the network devices is also disclosed.