Multiprotocol Label Switching (MPLS) is a routing technique in telecommunications networks that directs data from one node to the next based on labels rather than network addresses. Whereas network addresses identify endpoints, the labels identify established paths between endpoints. MPLS can encapsulate packets of various network protocols, hence the multiprotocol component of the name. MPLS supports a range of access technologies, including T1/E1, ATM, Frame Relay, and DSL.
A router is a networking device that forwards data packets between computer networks. Routers perform the traffic directing functions between networks and on the global Internet. Data sent through a network, such as a web page or email, is in the form of data packets. A packet is typically forwarded from one router to another router through the networks that constitute an internetwork until it reaches its destination node.
Routing is the process of selecting a path for traffic in a network or between or across multiple networks. Broadly, routing is performed in many types of networks, including circuit-switched networks, such as the public switched telephone network (PSTN), and computer networks, such as the Internet.
Wake-on-LAN is an Ethernet or Token Ring computer networking standard that allows a computer to be turned on or awakened from sleep mode by a network message.
Open Shortest Path First (OSPF) is a routing protocol for Internet Protocol (IP) networks. It uses a link state routing (LSR) algorithm and falls into the group of interior gateway protocols (IGPs), operating within a single autonomous system (AS).
The Address Resolution Protocol (ARP) is a communication protocol used for discovering the link layer address, such as a MAC address, associated with a given internet layer address, typically an IPv4 address. This mapping is a critical function in the Internet protocol suite. ARP was defined in 1982 by RFC 826, which is Internet Standard STD 37.
In computer networking, a routing table, or routing information base (RIB), is a data table stored in a router or a network host that lists the routes to particular network destinations, and in some cases, metrics (distances) associated with those routes. The routing table contains information about the topology of the network immediately around it.
Proxy ARP is a technique by which a proxy server on a given network answers the Address Resolution Protocol (ARP) queries for an IP address that is not on that network. The proxy is aware of the location of the traffic's destination and offers its own MAC address as the destination. The traffic directed to the proxy address is then typically routed by the proxy to the intended destination via another interface or via a tunnel.
Network address translation (NAT) is a method of mapping an IP address space into another by modifying network address information in the IP header of packets while they are in transit across a traffic routing device. The technique was originally used to bypass the need to assign a new address to every host when a network was moved, or when the upstream Internet service provider was replaced, but could not route the network's address space. It has become a popular and essential tool in conserving global address space in the face of IPv4 address exhaustion. One Internet-routable IP address of a NAT gateway can be used for an entire private network.
A multilayer switch (MLS) is a computer networking device that switches on OSI layer 2 like an ordinary network switch and provides extra functions on higher OSI layers. The MLS was invented by engineers at Digital Equipment Corporation.
A default gateway is the node in a computer network using the Internet protocol suite that serves as the forwarding host (router) to other networks when no other route specification matches the destination IP address of a packet.
The Neighbor Discovery Protocol (NDP), or simply Neighbor Discovery (ND), is a protocol of the Internet protocol suite used with Internet Protocol Version 6 (IPv6). It operates at the internet layer of the Internet model, and is responsible for gathering various information required for network communication, including the configuration of local connections and the domain name servers and gateways.
Reverse-path forwarding (RPF) is a technique used in modern routers for the purposes of ensuring loop-free forwarding of multicast packets in multicast routing and to help prevent IP address spoofing in unicast routing.
A forwarding information base (FIB), also known as a forwarding table or MAC table, is most commonly used in network bridging, routing, and similar functions to find the proper output network interface controller to which the input interface should forward a packet. It is a dynamic table that maps MAC addresses to ports. It is the essential mechanism that separates network switches from Ethernet hubs. Content-addressable memory (CAM) is typically used to efficiently implement the FIB, thus it is sometimes called a CAM table.
In network routing, the control plane is the part of the router architecture that is concerned with establishing the network topology, or the information in a routing table that defines what to do with incoming packets. Control plane functions, such as participating in routing protocols, run in the architectural control element. In most cases, the routing table contains a list of destination addresses and the outgoing interface(s) associated with each. Control plane logic also can identify certain packets to be discarded, as well as preferential treatment of certain packets for which a high quality of service is defined by such mechanisms as differentiated services.
In routing, the forwarding plane, sometimes called the data plane or user plane, defines the part of the router architecture that decides what to do with packets arriving on an inbound interface. Most commonly, it refers to a table in which the router looks up the destination address of the incoming packet and retrieves the information necessary to determine the path from the receiving element, through the internal forwarding fabric of the router, and to the proper outgoing interface(s).
Private VLAN, also known as port isolation, is a technique in computer networking where a VLAN contains switch ports that are restricted such that they can only communicate with a given uplink. The restricted ports are called private ports. Each private VLAN typically contains many private ports, and a single uplink. The uplink will typically be a port connected to a router, firewall, server, provider network, or similar central resource.
IP routing is the application of routing methodologies to IP networks. This involves not only protocols and technologies but includes the policies of the worldwide organization and configuration of Internet infrastructure. In each IP network node, IP routing involves the determination of a suitable path for a network packet from a source to its destination in an IP network. The process uses static configuration rules or dynamically obtained from routing protocols to select specific packet forwarding methods to direct traffic to the next available intermediate network node one hop closer to the desired final destination, a total path potentially spanning multiple computer networks.
In computer networking, a unicast flood occurs when a switch receives a unicast frame and the switch does not know that the addressee is on any particular switch port. Since the switch has no information regarding which port, if any, the addressee might be reached through, it forwards the frame through all ports aside from the one through which the frame was received.
Broadcast, unknown-unicast and multicast traffic is network traffic transmitted using one of three methods of sending data link layer network traffic to a destination of which the sender does not know the network address. This is achieved by sending the network traffic to multiple destinations on an Ethernet network. As a concept related to computer networking, it includes three types of Ethernet modes: broadcast, unicast and multicast Ethernet. BUM traffic refers to that kind of network traffic that will be forwarded to multiple destinations or that cannot be addressed to the intended destination only.