Arista Networks, Inc.

Rajesh Kumar Semwal

Amit Dattatray Ranpise

Alton Lo

Isidoros Kouvelas

Mohammad Imtiyaz

Kallol Mandal

Vijay Mahadevan

Aparna Sushrut Karanjkar

Prashant Srinivas

Victor Wen

Srinivas Subramanian

Kamlesh Raghuvanshi

Nitin Singh

Madhu Sudan

Santosh Kumar

Bharathram Pattabhiraman

Vishal Bandekar

Saravanan Balasubramanian

Ramakrishnan Ganapathy Iyer

Swati Patel

Faisal Iqbal

Saurabh Sarpal

Venkit Kasiviswanathan

First and second network devices may be configured to multihome a host. The first network device may advertise a first MAC and IP advertisement route indicative of a first link between the first network device and the host. The second network device may advertise a backup MAC and IP advertisement route indicative of a second link between the second network device and the host. Based on the backup MAC and IP advertisement route, the first network device may store a backup path for reaching the host via the second network device. After failure of the first link, the first network device may forward traffic destined for the host based on the stored backup path.

Backup route for network devices in multihoming configuration

Techniques disclosed herein provide a method for efficiently propagating address resolution reply messages. A first router in a first network receives an address resolution request message from a second router in a second network. The first router generates an entry for the address resolution request message and stores the entry in a pending address resolution requests table. When the first router receives a route advertisement, it extracts a network layer address from the route advertisement and determines whether the pending address resolution requests table includes an entry for the network layer address. If so, the router extracts a link layer address from the route advertisement and generates an address resolution reply message comprising the network layer address and the link layer address. The router then transmits the address resolution reply message to the second router.

Efficient ARP packet propagation

In response to receiving an ASR message, a VTEP generates a specially modified control plane message advertising the IP-to-MAC binding of the ASR message. The control plane message may be modified to indicate that it is not to be used for MAC learning. The control plane message is advertised over the network. When an intended recipient receives the message, it uses that message just for the IP-to-MAC binding. When an unintended recipient receives the message, it may drop it as invalid.

Efficient ARP bindings distribution in VPN networks

Techniques described herein provide for fast updating of a forwarding table in a single active multihoming configuration. A first network device that is not connected to an ethernet segment (ES), receives a plurality of ethernet segment (ES) routes (e.g., EVPN type-4 routes) from a plurality of network devices that are connected to a host via the ES. When connectivity is lost to the on a designated forwarded for the ES, t the first network device performed a designated forwarding election algorithm based on the plurality of the received ES routes, to identify that a second network device of the plurality of network devices is designated as a new forwarding device. The first network device modifies an entry in a forwarding table to indicate that the host is now reachable via the second network device.

Multihoming optimizations for fast failover in single-active networks

A method for synchronizing a binding process among a group of network devices connected to a server that is multi-homed to the group of network devices in provided. The method is executed by a first network device among the group of network devices and includes: receiving, from the server, network traffic associated with a host executing on the server; configuring, using the network traffic, a binding between the first network device and the host and setting a binding status of the first network device for the host to a first status; and transmitting, in response to the setting and via an out-of-band (OOB) channel to a second network device among the plurality of network devices, first binding instructions for causing the second network device set a binding status of the second network device for the host to a second status different from the first status.

Address resolution protocol (ARP) for multi-homed devices

In general, in one aspect, embodiments relate to a method for managing network devices in a network. The method includes making, by a network device, a determination that there are no established sessions between the network device and any of a plurality of network devices, wherein the network comprises the network device and the plurality of network devices, and in response to the determination, disabling, by the network device, an interface associated with a link between the network device and a second network device, wherein the second network device is external to the network.

Traffic loss avoidance in a border gateway protocol (BGP) network via flexible session tracking

Systems and methods are provided herein for a mechanism for faster convergence of network traffic after a network device's link is interrupted by leveraging the withdrawal of the ethernet virtual private network (EVPN) auto discovery (AD) route. This may be accomplished by a first device checking an ethernet segment identifier (ESI) status flag before generating an entry in the first device's forwarding table, where the entry is based on an IP route for a host received by a second network device. In response to receiving a withdrawal of an EVPN AD route from the second device, the first device may update the ESI status flag to indicate that the host on the ethernet segment (ES) is reachable only via the third device and update the entry that was based on the IP route for the host received by the second network device to prevent sending traffic to the host via the second device.

Systems and methods for convergence of network traffic after an interruption of a network device's link

Systems and methods are provided herein for allocating the same ESI label on multihomed peers for a given ES. In some embodiments, each network device that provides multihoming to a host using an ES, advertises EVPN AD per ES routes to each other, wherein the EVPN AD per ES routes comprise an ESI label associated with the ES. Because the network devices advertise the same ESI label for the ES, a first network device generates a bitmap. The first network device uses the bitmap to include the advertised ESI label in replicated packets that the first network device forwards to the other network devices that provide multihoming to the host via the ES. The network devices that consider themselves non-DF devices will drop the packet. The network devices that consider themselves the DF device will not forward the packet to the host via the ES because of the ESI label.

Shared ethernet segment identifier label allocation for ethernet virtual private network multihoming

Peer devices in a peer group of provider edge devices to which a customer edge device is multi-homed, advertise Selective Multicast Ethernet Tag (SMET) routes to other peer devices on a core to receive traffic addressed to a multicast group. The peer devices in the peer group advertise the SMET routes irrespective of whether they are the designated forwarder or not. A peer device receiving traffic for the multicast group will drop the packet if it is not the designated forwarder and will forward the packet if it is the designated forwarder.

Fast convergence for multicast traffic on multilink failover

Embodiments described herein relate to techniques for designated forwarder (DF) elections, which may include: obtaining DF candidates that are part of a supplementary broadcast domain (SBD), wherein the DF candidate is one of the plurality of DF candidates for the SBD; performing a SBD DF election process to determine an SBD DF winner from among the DF candidates; making a first determination that the DF candidate is not the SBD DF winner; making second determination that a first broadcast domain (BD) provisioned on the DF candidate is not provisioned on the SBD DF winner; excluding the first BD from a set of BDs that are also provisioned on the SBD DF winner; performing additional DF election processes for each BD of the set of BDs; and processing multicast traffic based at least in part on the SBD DF election process and the additional DF election processes.

Modified designated forwarder election process for non-overlapping broadcast domains

Techniques disclosed herein provide a method for configuring a network in DCI environment. An EVPN session is established between a first gateway device of a first network, and a second gateway device of a second network that are linked by L2 DCI link. An ESI is allocated for that EVPN session. A label is created for every combination of the ESI and media access control virtual routing and forwarding table (MAC VRF) that is locally configured at the first gateway device. An EVPN path is received for a host in the first network that is associated with MAC VRF. The path in imported the first MAC VRF by the first gateway device and exported via the inter-DCI EVPN session. The second gateway device identifies a label for MAC and re-exports it in local EVPN session with the identified label.

Systems and method for using DCI-ESI to build highly scalable EVPN DCI networks

Techniques described herein provide for expediting routing convergence in EVPN with multihomed ethernet segment when one of the redundant devices loses connection to the ethernet segment. When a first redundant device receives EVPN auto discovery (AD) route advertising an ethernet segment from a second redundant device, it creates an entry for a forwarding table. The entry has, for an advertised MAC address, a local identifier of the ethernet segment (marked as active next hop) and the identifier of the second network device (marked as backup next hop). When a packet for that MAC address is received, the first redundant device routes the data using data from the entry. In particular, the first redundant device uses the local identifier of the ethernet segment as next hop when the ethernet segment link is active; and uses the identifier of the second network device as next hop when the ethernet segment is down.

EVPN multihoming optimizations for ethernet segment connection interruptions

A method for initializing the border gateway protocol (BGP) on network devices. The method includes initializing a plurality of BGP convergence variables corresponding to a plurality of BGP sessions with a plurality of peer network devices. The first network device initializes the plurality of BGP sessions with the plurality of peer network devices, and receives from each of the plurality of peer network devices, route updates and a plurality of markers. The BGP convergence variables are updated and it is determined that first network device has received all the route updates. The duration of the BGP session is less than a C_TIMEOUT value for that peer network device, exceeds an I_P_TIMEOUT value, where the C_TIMEOUT value is greater than the I_P_TIMEOUT value. The first network device updates a routing information base (RIB) using the route updates and updates a forwarding information base (FIB) using the updated RIB.

Method and system for initializing the border gateway protocol on network devices

A network element is provided. The network element includes a tunneling endpoint having a virtual address. The tunneling endpoint is configured to receive an address resolution reply that has a destination MAC (media access control) address matching the virtual address of the tunneling endpoint and is from a network device in a first network that includes the tunneling endpoint. The tunneling endpoint is further configured to send the address resolution reply via an interconnect to a further tunneling endpoint in a further network. A method for address resolution in virtual extensible networks is also provided.

Address resolution in virtual extensible networks

Techniques described herein provide for fast updating of a forwarding table in a single active multihoming configuration. A first network device that is not connected to an ethernet segment (ES), receives a plurality of ES routes (e.g., EVPN type-4 routes) from a plurality of network devices that are connected to a host via the ES. When connectivity is lost to a designated forwarded for the ES, the first network device performs a designated forwarding election algorithm based on the plurality of received ES routes, to identify that a second network device of the plurality of network devices is designated as a new forwarding device. The first network device modifies an entry in a forwarding table to indicate that the host is now reachable via the second network device.

Growing community of inventors

Sunnyvale, CA, United States of America

Rajesh Kumar Semwal