Juniper Networks, Inc.

Kaushik Ghosh

Kireeti Kompella

Nitin Kumar

Dennis C Ferguson

Steven Lin

Junan Chen

Siva Gaggara

Rajiv N Patel

Scott Mackie

Anil Lohiya

Ramasamy Ramanathan

Bharani Chadalavada

Manoj Sharma

Raj Tuplur

Shrinivasa Kini

Cunzhi Lu

Vinay Nallamothu

Amit Shukla

Kannan Varadhan

Manoj Leelanivas

Raj Tuplar

In general, techniques are described in which packet replicators of a network device cooperate to generate a distributed hierarchical forwarding structure that the packet replicators then use to replicate and forward multicast packets to multiple output interfaces. For example, packet forwarding engines (PFEs) of a router each receive a new list of interfaces for a multicast packet stream. The PFEs individually construct a hierarchical forwarding structure based on the interface list. The hierarchical forwarding structure specifies interrelationships among the PFEs, which occupy nodes within the hierarchy. Each child PFE determines from the hierarchical forwarding structure the identity of a parent PFE and issues a token, constituting forwarding state for the distributed hierarchical forwarding structure, to the parent PFE. The parent PFE uses the token to identify packets of the multicast traffic to the child PFE during replication and forwarding of multicast packets proceeding according to the hierarchical forwarding structure.

Distributed generation of hierarchical multicast forwarding structures

In general, techniques for facilitating a distributed network (L3) subnet by which multiple independent control planes of network devices connected to physically separate L2 networks provide L2 reachability to/from a single L3 subnet. In some examples, a shared L2 network physically situated to connect a plurality of physically separate L2 networks 'stitches' the L2 networks together within the respective, independent control planes of switches such that the control planes bridge L2 traffic for a single bridge domain for the separate L2 networks to the shared L2 network and visa-versa. Each of the independent control planes may be configured with a virtual IRB instance associated with the bridge domain and with a common network subnet. Each of the virtual IRBs provides a functionally similar routing interface for the single bridge domain for the separate L2 networks and allows the shared network subnet to be distributed among the independent control planes.

Distributed network subnet

Selection of proper virtual routing and forwarding (VRF) tables is based on a logical interface that is not associated with a physical interface. The selected VRF table is used to perform an output interface lookup for outgoing packets. In one example, a router includes a plurality of network interfaces, and a processing unit configured to select a logical interface not associated with any of the plurality of network interfaces based on an association with a received packet of a virtual private network, select one of a plurality of VRF tables in which to perform an output interface lookup for the packet that corresponds to the selected logical interface, and determine one of the plurality of network interfaces from the one of the plurality of VRF tables based on a destination of the packet, wherein the determined one of the plurality of network interfaces is configured to forward the packet.

Tunneling from a provider edge routing device to a remote customer edge network device

A route for a data unit through a network may be defined based on a number of next hops. Exemplary embodiments described herein may implement a router forwarding table as a chained list of references to next hops. In one implementation, a device includes a forwarding table that includes: a first table configured to store, for each of a plurality of routes for data units in a network, a chain of links to next hops for the routes; and a second table configured to store the next hops. The device also includes a forwarding engine configured to assemble the next hops for the data units based on using the chain of links in the first table to retrieve the next hops in the second table and to forward the data units in the network based on the assembled next hops.

Next hop chaining for forwarding data in a network switching device

A network device includes a memory, a routing engine and a forwarding engine. The memory stores a forwarding table and the routing engine constructs a first composite next hop that includes multiple next hops, where each of the multiple next hops represents an action to be taken on a data unit as it transits the network device or represents another composite next hop, and where the first composite next hop specifies a function to be performed on the plurality of next hops. The routing engine further stores the composite next hop in an entry of the forwarding table. The forwarding engine retrieves the composite next hop from the forwarding table, and forwards a data unit towards one or more network destinations based on the composite next hop.

Composite next hops for forwarding data in a network switching device

A device may include a donor to maintain a pool of addresses; a group of borrowers to obtain addresses from the donor; a daemon that has registered an interest in one or more borrowers in the group of borrowers; and a library to maintain first relationships between donors and borrowers that have obtained addresses from the donors, maintain second relationships between daemons and borrowers in which the daemons have registered an interest, receive a notification regarding an incident associated with the donor, identify, in response to the notification, the group of borrowers based on the first relationships, determine that the daemon has registered an interest in the one or more borrowers in the group of borrowers based on the second relationships, and output, to the daemon, a notification regarding the incident associated with the donor.

Donor/borrower incident notification for daemons

Layer two (L2) forwarding of multicast traffic between routers of a Virtual Private local area network (LAN) Service (VPLS) domain is described. For example, the techniques allow multicast traffic to generally be forwarded between VPLS routers based on L2 information only, without requiring the routers to examine any layer three (L3) information carried by the multicast traffic for forwarding the multicast traffic. A router dynamically learns a mapping between a multicast source device and an L2 address of a router that introduces multicast traffic into the VPLS domain from the multicast source device. The router installs forwarding information based on the mapping that specifies the L2 address of the router that introduces the multicast traffic, and an L2 multicast group address of the multicast group, and forwards multicast traffic for the multicast group based on the forwarding information without reference to any L3 information of the multicast traffic.

Forwarding multicast packets in a VPLS router on the basis of MAC addresses

An egress device of a network tunnel is configured to receive fragmented packets over a tunnel interface when the network tunnel is defined using information that is not present in all of the fragmented packets. For example, an egress device includes an interface to receive packets associated with the network tunnel, at least some of the packets being fragmented packets that are fragments of tunnel encapsulated packets. Some of the fragmented packets include network layer information associated with a network layer header of an original unfragmented tunnel encapsulated packet and do not include transport layer information associated with a transport layer header of the original unfragmented tunnel encapsulated packet. A forwarding engine of the egress device uses a multi-stage chained lookup to determine whether packets conform to tunnel definitions for the network tunnel that define the network tunnel by specifying both network layer information and transport layer information required for the packets.

Accepting packets with incomplete tunnel-header information on a tunnel interface

A network device includes a processor that executes a software module above an operating system of a network device, wherein the software module is configured to create a set of forwarding structures for use in forwarding network traffic with the network device without regard to limitations of an underlying architecture of the forwarding plane. The network device also includes a forwarding structure control module operative within or below the operating system of the network device, wherein the forwarding structure control module is configured to create a set of derived forwarding structures based on the set of forwarding structures provided by the software module for installation in the forwarding information of the forwarding plane. The derived set of forwarding structures is created in accordance with the limitations of the underlying architecture of the forwarding plane.

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Sunnyvale, CA, United States of America

Kaushik Ghosh