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MAC Table
A forwarding information base (FIB), also known as a forwarding table or MAC (address) 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. Applications at data link layer At the data link layer, a FIB is most notably used to facilitate Ethernet bridging based on MAC addresses. Other data-link-layer technologies using FIBs include Frame Relay, Asynchronous Transfer Mode (ATM) and Multiprotocol Label Switching (MPLS). Bridging The role of an Ethernet switch is to forward Ethernet frames from one port to another. The presence of a FIB is one attribute that separates a switch from a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bridging (networking)
A network bridge is a computer networking device that creates a single, aggregate network from multiple communication networks or network segments. This function is called network bridging. Bridging is distinct from routing. Routing allows multiple networks to communicate independently and yet remain separate, whereas bridging connects two separate networks as if they were a single network. In the OSI model, bridging is performed in the data link layer (layer 2). If one or more segments of the bridged network are wireless, the device is known as a wireless bridge. The main types of network bridging technologies are simple bridging, multiport bridging, and learning or transparent bridging. Transparent bridging Transparent bridging uses a table called the '' forwarding information base'' to control the forwarding of frames between network segments. The table starts empty and entries are added as the bridge receives frames. If a destination address entry is not found in the ta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Link Connection Identifier
A data link connection identifier (DLCI) is a Frame Relay 10-bit-wide link-local virtual circuit identifier used to assign frames to a specific PVC or SVC. Frame Relay networks use DLCIs to statistically multiplex frames. DLCIs are preloaded into each switch and act as road signs to the traveling frames. The standard allows the existence of 1024 DLCIs. DLCI 0 is reserved for the ANSI/q993a LMI standard—only numbers 16 to 976 are usable for end-user equipment. DLCI 1023 is reserved for Cisco Cisco Systems, Inc. (using the trademark Cisco) is an American multinational digital communications technology conglomerate corporation headquartered in San Jose, California. Cisco develops, manufactures, and sells networking hardware, s ... LMI, however, numbers 16 to 1007 are usable. In summary, if using Cisco LMI, numbers from 16 to 1007 are available for end-user equipment. The rest are reserved for various management purposes. DLCI are Layer 2 Addresses that are locally sig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IP Address Spoofing
In computer networking, IP address spoofing or IP spoofing is the creation of Internet Protocol (IP) packets with a false source IP address, for the purpose of impersonating another computing system. Background The basic protocol for sending data over the Internet network and many other computer networks is the Internet Protocol (IP). The protocol specifies that each IP packet must have a header which contains (among other things) the IP address of the sender of the packet. The source IP address is normally the address that the packet was sent from, but the sender's address in the header can be altered, so that to the recipient it appears that the packet came from another source. The protocol requires the receiving computer to send back a response to the source IP address therefore spoofing is mainly used when the sender can anticipate the network response or does not care about the response. The source IP address provides only limited information about the sender. It may pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reverse-path Forwarding
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. In standard unicast IP routing, the router forwards the packet away from the source to make progress along the distribution tree and prevent routing loops. In contrast, the router's multicast forwarding state runs more logically by organizing tables based on the reverse path, from the receiver back to the root of the distribution tree at the source of the multicast. This approach is known as reverse-path forwarding. Multicast RPF Multicast RPF, typically denoted simply as RPF, is used in conjunction with a multicast routing protocol such as Multicast Source Discovery Protocol or Protocol Independent Multicast to ensure loop-free forwarding of multicast packets. In multicast routing, the decision to forward traffic is based upon source address and not on desti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IETF
The Internet Engineering Task Force (IETF) is a standards organization for the Internet standard, Internet and is responsible for the technical standards that make up the Internet protocol suite (TCP/IP). It has no formal membership roster or requirements and all its participants are volunteers. Their work is usually funded by employers or other sponsors. The IETF was initially supported by the federal government of the United States but since 1993 has operated under the auspices of the Internet Society, a non-profit organization with local chapters around the world. Organization There is no membership in the IETF. Anyone can participate by signing up to a working group mailing list, or registering for an IETF meeting. The IETF operates in a bottom-up task creation mode, largely driven by working groups. Each working group normally has appointed two co-chairs (occasionally three); a charter that describes its focus; and what it is expected to produce, and when. It is open ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Access-control List
In computer security, an access-control list (ACL) is a list of permissions associated with a system resource (object or facility). An ACL specifies which users or system processes are granted access to resources, as well as what operations are allowed on given resources. Each entry in a typical ACL specifies a subject and an operation. For instance, * If a file object has an ACL that contains, this would give Alice permission to read and write the file and give Bob permission only to read it. * If the Resource Access Control Facility (RACF) profile CONSOLE CLASS(TSOAUTH) has an ACL that contains, this would give ALICE permission to use the TSO CONSOLE command. Implementations Many kinds of operating systems implement ACLs or have a historical implementation; the first implementation of ACLs was in the filesystem of Multics in 1965. Filesystem ACLs A filesystem ACL is a data structure (usually a table) containing entries that specify individual user or group rights to spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ingress Filtering
In computer networking, ingress filtering is a technique used to ensure that incoming packets are actually from the networks from which they claim to originate. This can be used as a countermeasure against various spoofing attacks where the attacker's packets contain fake IP addresses. Spoofing is often used in denial-of-service attacks, and mitigating these is a primary application of ingress filtering. Problem Networks receive packets from other networks. Normally a packet will contain the IP address of the computer that originally sent it. This allows devices in the receiving network to know where it came from, allowing a reply to be routed back (amongst other things), except when IP addresses are used through a proxy or a spoofed IP address, which does not pinpoint a specific user within that pool of users. A sender IP address can be faked ( spoofed), characterizing a spoofing attack. This disguises the origin of packets sent, for example in a denial-of-service attack. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Best Current Practice
A best current practice, abbreviated as BCP, is a ''de facto'' level of performance in engineering and information technology. It is more flexible than a standard, since techniques and tools are continually evolving. The Internet Engineering Task Force publishes Best Current Practice documents in a numbered document series. Each document in this series is paired with the currently valid Request for Comments (RFC) document. BCP was introduced in RFC-1818.rfc:1818 BCPs are document guidelines, processes, methods, and other matters not suitable for standardization. The Internet standards process itself is defined in a series of BCPs, as is the formal organizational structure of the IETF, Internet Engineering Steering Group, Internet Architecture Board, and other groups involved in that process. IETF's separate Standard Track (STD) document series defines the fully standardized network protocols of the Internet, such as the Internet Protocol, the Transmission Control Protocol, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control Plane
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 or interfaces associated with each. Control plane logic can also 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. Depending on the specific router implementation, there may be a separate forwarding information base that is populated by the control plane, but used by the high-speed forwarding plane to look up packets and decide how to handle them. In computing, the control plane is the part of the software that con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Routing Protocol
A routing protocol specifies how routers communicate with each other to distribute information that enables them to select paths between nodes on a computer network. Routers perform the traffic directing functions on the Internet; data packets are forwarded through the networks of the internet from router to router until they reach their destination computer. Routing algorithms determine the specific choice of route. Each router has a prior knowledge only of networks attached to it directly. A routing protocol shares this information first among immediate neighbors, and then throughout the network. This way, routers gain knowledge of the topology of the network. The ability of routing protocols to dynamically adjust to changing conditions such as disabled connections and components and route data around obstructions is what gives the Internet its fault tolerance and high availability. The specific characteristics of routing protocols include the manner in which they avoid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Routing Information Base
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. The construction of routing tables is the primary goal of routing protocols. Static routes are entries that are fixed, rather than resulting from routing protocols and network topology discovery procedures. Overview A routing table is analogous to a distribution map in package delivery. Whenever a node needs to send data to another node on a network, it must first know ''where'' to send it. If the node cannot directly connect to the destination node, it has to send it via other nodes along a route to the destination node. Each node needs to keep track of which way to deliver various packages of data, and for this it uses a rout ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IP Address
An Internet Protocol address (IP address) is a numerical label such as that is assigned to a device connected to a computer network that uses the Internet Protocol for communication. IP addresses serve two main functions: network interface identification, and location addressing. Internet Protocol version 4 (IPv4) was the first standalone specification for the IP address, and has been in use since 1983. IPv4 addresses are defined as a 32-bit number, which became too small to provide enough addresses as the internet grew, leading to IPv4 address exhaustion over the 2010s. Its designated successor, IPv6, uses 128 bits for the IP address, giving it a larger address space. Although IPv6 deployment has been ongoing since the mid-2000s, both IPv4 and IPv6 are still used side-by-side . IP addresses are usually displayed in a human-readable notation, but systems may use them in various different computer number formats. CIDR notation can also be used to designate how much ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
