Abstract: A logical routing element (LRE) having multiple designated instances for routing packets from physical hosts (PH) to a logical network is provided. A PH in a network segment with multiple designated instances can choose among the multiple designated instances for sending network traffic to other network nodes in the logical network according to a load balancing algorithm. Each logical interface (LIF) of an LRE is defined to be addressable by multiple identifiers or addresses, and each LIF identifier or address is assigned to a different designated instance.

Abstract: A novel method for fully utilizing the multicast or broadcast capability of a physical network is provided. The method identifies segments of the network within which broadcast traffic, multicast traffic, or traffic to unknown recipients (BUM traffic) is allowed or enabled. The identified segment encompasses parts of the network that the BUM traffic is able reach while excluding parts of the network nodes that the BUM traffic is unable to reach. Each identified segment includes network nodes that are interconnected by physical network hardware that supports BUM traffic. The method identifies multiple BUM traffic segments in a given network that each supports its own BUM traffic. The different BUM traffic segments are interconnected by physical network hardware that does not support BUM network traffic. Each identified segment is assigned an identifier that uniquely distinguishes the identified segment from other identified segments.

Abstract: Some embodiments provide a method for a computing device serving as a host machine in a logical network. The method executes several virtual machines that are in several different segments of the logical network. The method operates a managed physical routing element (MPRE) for routing data packets between different segments of the logical network. The MPRE includes several logical interfaces, each of which is for receiving data packets from a different segment of the logical network. Each of the logical interfaces is addressable by a network layer address. The method intercepts an Address Resolution Protocol (ARP) broadcast message when the destination address matches the network address of one of the logical interfaces. The method formulates an ARP reply to the ARP broadcast message.

Abstract: Some embodiments provide a system that includes several host machines for hosting several virtual machines and a physical network for interconnecting the host machines. Each host machine includes a managed physical switching element (MPSE) including several ports for performing link layer forwarding of packets to and from a set of virtual machines running on the host machine. Each port is associated with a unique media access control (MAC) address. Each host machine includes a managed routing element (MPRE) for receiving a data packet from a port of the MPSE and performing network layer routing in order to forward the received data packet from a first virtual machine of a first network segment to a second virtual machine of a second network segment.

Abstract: Some embodiments provide a method of operating several logical networks over a network virtualization infrastructure. The method defines a managed physical switching element (MPSE) that includes several ports for forwarding packets to and from a plurality of virtual machines. Each port is associated with a unique media access control (MAC) address. The method defines several managed physical routing elements (MPREs) for the several different logical networks. Each MPRE is for receiving data packets from a same port of the MPSE. Each MPRE is defined for a different logical network and for routing data packets between different segments of the logical network. The method provides the defined MPSE and the defined plurality of MPREs to a plurality of host machines as configuration data.

Abstract: Some embodiments provide a system that includes a first set of virtual machines belonging to a first overlay network and a second set of virtual machines belonging to a second overlay network. The first and second sets of virtual machines operate in several host machines, each of which includes a managed physical routing element (MPRE) for routing data packet between virtual machines in different overlay networks. A particular MPRE is configured as a bridge for routing packets between virtual machines that are in different overlay networks but in a same IP (internet protocol) subnet.

Abstract: A novel method of conducting multicast traffic in a network is provided. The network includes multiple endpoints that receive messages from the network and generate messages for the network. The endpoints are located in different segments of the network, each segment including one or more of the endpoints. For a source endpoint to replicate a particular message (e.g., a data packet) for all endpoints belonging to a particular replication group (i.e., multicast group) within the network, the source endpoint replicates the particular message to each endpoint within the source endpoint's own segment and to a proxy endpoint in each of the other segments. Each proxy endpoint in turn replicates the particular message to all endpoints belonging to the particular replication group within the proxy endpoint's own segment.

Abstract: Techniques for efficiently storing and using routing and associated next-hop information in a network device. The amount of next-hop information that is stored for routes in a routing table is reduced by reducing the amount of duplicate next-hop information that is stored by a network device.

Abstract: Techniques for provisioning single or multistage networks using Ethernet Service Instances (ESIs). In one embodiment, an ESI is a logical entity or object that stores information that may be used to provision a network. An ESI may represent a logical entity that identifies a grouping of elements of a network or network device and associated attributes. Hierarchical relationships may be created between ESIs. The hierarchical relationships are used to perform packet-level processing including performing network packet encapsulations.

Abstract: Techniques for facilitating link redundancy using an enhanced version of Virtual Switch Redundancy Protocol (VSRP), referred to herein as VSRP2. In one set of embodiments, a group of Layer 2 and/or Layer 2/3 devices (switches) can act in concert as a VSRP2 virtual switch. A first switch in the group (a VSRP2 master switch) can forward, via a first link, data traffic to/from a network device in a connected Layer 2 network. A second switch in the group (a VSRP2 backup switch) can block, at a second link, data traffic to/from the same network device. If the first link fails or otherwise becomes unavailable, the VSRP2 backup switch can detect the link failure and begin forwarding, via the second link, data traffic to/from the network device. In this manner, redundancy can be provided at the link level between the VSRP2 virtual switch and the Layer 2 network.

Abstract: Techniques for provisioning single or multistage networks using Ethernet Service Instances (ESIs). In one embodiment, an ESI is a logical entity or object that stores information that may be used to provision a network. An ESI may represent a logical entity that identifies a grouping of elements of a network or network device and associated attributes. Hierarchical relationships may be created between ESIs. The hierarchical relationships are used to perform packet-level processing including performing network packet encapsulations.

Abstract: Techniques for facilitating link redundancy using an enhanced version of Virtual Switch Redundancy Protocol (VSRP), referred to herein as VSRP2. In one set of embodiments, a group of Layer 2 and/or Layer 2/3 devices (switches) can act in concert as a VSRP2 virtual switch. A first switch in the group (a VSRP2 master switch) can forward, via a first link, data traffic to/from a network device in a connected Layer 2 network. A second switch in the group (a VSRP2 backup switch) can block, at a second link, data traffic to/from the same network device. If the first link fails or otherwise becomes unavailable, the VSRP2 backup switch can detect the link failure and begin forwarding, via the second link, data traffic to/from the network device. In this manner, redundancy can be provided at the link level between the VSRP2 virtual switch and the Layer 2 network.

Abstract: The number of content addressable memory (CAM) lookups is reduced from two to one. Each side (left and right sides) of a CAM is programmed with network addresses, such as IP addresses, based on certain bits of the network addresses. These bits of the network addresses (which represent packet routes) are examined and used to determine whether the particular network address is to be placed on the left or right sides of the CAM. The grouping of certain network addresses either on the left or right sides of the CAM can be performed by examining an individual bit of each network address, by performing an exclusive OR (XOR) operation on a plurality of bits of each network address, and/or by searching for bit patterns of the network address in a decision table. Network addresses that cannot be readily assigned to a particular side of the CAM using these grouping techniques are programmed into both sides of the CAM.

Abstract: The number of content addressable memory (CAM) lookups is reduced from two to one. Each side (left and right sides) of a CAM is programmed with network addresses, such as IP addresses, based on certain bits of the network addresses. These bits of the network addresses (which represent packet routes) are examined and used to determine whether the particular network address is to be placed on the left or right sides of the CAM. The grouping of certain network addresses either on the left or right sides of the CAM can be performed by examining an individual bit of each network address, by performing an exclusive OR (XOR) operation on a plurality of bits of each network address, and/or by searching for bit patterns of the network address in a decision table. Network addresses that cannot be readily assigned to a particular side of the CAM using these grouping techniques are programmed into both sides of the CAM.

Abstract: Techniques for efficiently storing and using routing and associated next-hop information in a network device. The amount of next-hop information that is stored for routes in a routing table is reduced by reducing the amount of duplicate next-hop information that is stored by a network device.

Abstract: Techniques for provisioning single or multistage networks using Ethernet Service Instances (ESIs). In one embodiment, an ESI is a logical entity or object that stores information that may be used to provision a network. An ESI may represent a logical entity that identifies a grouping of elements of a network or network device and associated attributes. Hierarchical relationships may be created between ESIs. The hierarchical relationships are used to perform packet-level processing including performing network packet encapsulations.

Abstract: The number of content addressable memory (CAM) lookups is reduced from two to one. Each side (left and right sides) of a CAM is programmed with network addresses, such as IP addresses, based on certain bits of the network addresses. These bits of the network addresses (which represent packet routes) are examined and used to determine whether the particular network address is to be placed on the left or right sides of the CAM. The grouping of certain network addresses either on the left or right sides of the CAM can be performed by examining an individual bit of each network address, by performing an exclusive OR (XOR) operation on a plurality of bits of each network address, and/or by searching for bit patterns of the network address in a decision table. Network addresses that cannot be readily assigned to a particular side of the CAM using these grouping techniques are programmed into both sides of the CAM.

Abstract: The number of content addressable memory (CAM) lookups is reduced from two to one. Each side (left and right sides) of a CAM is programmed with network addresses, such as IP addresses, based on certain bits of the network addresses. These bits of the network addresses (which represent packet routes) are examined and used to determine whether the particular network address is to be placed on the left or right sides of the CAM. The grouping of certain network addresses either on the left or right sides of the CAM can be performed by examining an individual bit of each network address, by performing an exclusive OR (XOR) operation on a plurality of bits of each network address, and/or by searching for bit patterns of the network address in a decision table. Network addresses that cannot be readily assigned to a particular side of the CAM using these grouping techniques are programmed into both sides of the CAM.

Abstract: The number of content addressable memory (CAM) lookups is reduced from two to one. Each side (left and right sides) of a CAM is programmed with network addresses, such as IP addresses, based on certain bits of the network addresses. These bits of the network addresses (which represent packet routes) are examined and used to determine whether the particular network address is to be placed on the left or right sides of the CAM. The grouping of certain network addresses either on the left or right sides of the CAM can be performed by examining an individual bit of each network address, by performing an exclusive OR (XOR) operation on a plurality of bits of each network address, and/or by searching for bit patterns of the network address in a decision table. Network addresses that cannot be readily assigned to a particular side of the CAM using these grouping techniques are programmed into both sides of the CAM.