|
IGRP
Interior Gateway Routing Protocol (IGRP) is a distance vector interior gateway protocol (IGP) developed by Cisco. It is used by routers to exchange routing data within an autonomous system. IGRP is a proprietary protocol. IGRP was created in part to overcome the limitations of RIP (maximum hop count of only 15, and a single routing metric) when used within large networks. IGRP supports multiple metrics for each route, including bandwidth, delay, load, and reliability; to compare two routes these metrics are combined into a single metric, using a formula which can be adjusted through the use of pre-set constants. By default, the IGRP composite metric is a sum of the segment delays and the lowest segment bandwidth. The maximum configurable hop count of IGRP-routed packets is 255 (default 100), and routing updates are broadcast every 90 seconds (by default). IGRP uses protocol number 9 for communication.{{cite web , url=https://www.iana.org/assignments/protocol-numbers/protocol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EIGRP
Enhanced Interior Gateway Routing Protocol (EIGRP) is an advanced distance-vector routing protocol that is used on a computer network for automating routing decisions and configuration. The protocol was designed by Cisco Systems as a proprietary protocol, available only on Cisco routers. In 2013 Cisco decided to allow other vendors freely implement limited version of EIGRP with some of its associated features such as High Availability (HA), while withholding other EIGRP features such as EIGRP stub, needed for DMVPN and large-scale campus deployment, exclusively for themselves. Information needed for implementation was published with informational status as in 2016, which did not make it into an Internet Standards Track specification and allowed Cisco to retain control of the EIGRP protocol. EIGRP is used on a router to share routes with other routers within the same autonomous system. Unlike other well known routing protocols, such as RIP, EIGRP only sends incremental updates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Routing Information Protocol
The Routing Information Protocol (RIP) is one of the oldest distance-vector routing protocols which employs the hop count as a routing metric. RIP prevents routing loops by implementing a limit on the number of hops allowed in a path from source to destination. The largest number of hops allowed for RIP is 15, which limits the size of networks that RIP can support. RIP implements the split horizon, route poisoning, and holddown mechanisms to prevent incorrect routing information from being propagated. In RIPv1 routers broadcast updates with their routing table every 30 seconds. In the early deployments, routing tables were small enough that the traffic was not significant. As networks grew in size, however, it became evident there could be a massive traffic burst every 30 seconds, even if the routers had been initialized at random times. In most networking environments, RIP is not the preferred choice of routing protocol, as its time to converge and scalability are poor comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diffusing Update Algorithm
The diffusing update algorithm (DUAL) is the algorithm used by Cisco's EIGRP routing protocol to ensure that a given route is recalculated globally whenever it might cause a routing loop. It was developed by J.J. Garcia-Luna-Aceves at SRI International. The full name of the algorithm is DUAL finite-state machine (DUAL FSM). EIGRP is responsible for the routing within an autonomous system, and DUAL responds to changes in the routing topology and dynamically adjusts the routing tables of the router automatically. EIGRP uses a feasibility condition to ensure that only loop-free routes are ever selected. The feasibility condition is conservative: when the condition is true, no loops can occur, but the condition might under some circumstances reject all routes to a destination although some are loop-free. When no feasible route to a destination is available, the DUAL algorithm invokes a diffusing computation to ensure that all traces of the problematic route are eliminated from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distance-vector Routing Protocol
A distance-vector routing protocol in data networks determines the best route for data packets based on distance. Distance-vector routing protocols measure the distance by the number of routers a packet has to pass; one router counts as one hop. Some distance-vector protocols also take into account network latency and other factors that influence traffic on a given route. To determine the best route across a network, routers using a distance-vector protocol exchange information with one another, usually routing tables plus hop counts for destination networks and possibly other traffic information. Distance-vector routing protocols also require that a router inform its neighbours of network topology changes periodically. Distance-vector routing protocols use the Bellman–Ford algorithm to calculate the best route. Another way of calculating the best route across a network is based on link cost, and is implemented through link-state routing protocols. The term ''distance vector' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of IP Protocol Numbers
This is a list of the IP protocol numbers found in the field ''Protocol'' of the IPv4 header and the ''Next Header'' field of the IPv6 header. It is an identifier for the encapsulated protocol and determines the layout of the data that immediately follows the header. Both fields are eight bits wide. Protocol numbers are maintained and published by the Internet Assigned Numbers Authority (IANA). {, class="wikitable" , - ! Hex ! Protocol Number !! Keyword !! Protocol !! References/ RFC , - , 0x00 , 0 , HOPOPT , IPv6 Hop-by-Hop Option , , - , 0x01 , 1 , ICMP , Internet Control Message Protocol , , - , 0x02 , 2 , IGMP , Internet Group Management Protocol , , - , 0x03 , 3 , GGP , Gateway-to-Gateway Protocol , , - , 0x04 , 4 , IP-in-IP , IP in IP (encapsulation) , , - , 0x05 , 5 , ST , Internet Stream Protocol , , , - , 0x06 , 6 , TCP , Transmission Control Protocol , , - , 0x07 , 7 , CBT , Core-based trees , , - , 0x08 , 8 , EGP , ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interior Gateway Protocol
An interior gateway protocol (IGP) or Interior routing protocol is a type of routing protocol used for exchanging routing table information between gateways (commonly routers) ''within'' an autonomous system (for example, a system of corporate local area networks). This routing information can then be used to route network-layer protocols like IP. Interior gateway protocols can be divided into two categories: distance-vector routing protocols and link-state routing protocols. Specific examples of IGPs include Open Shortest Path First (OSPF), Routing Information Protocol (RIP), Intermediate System to Intermediate System (IS-IS) and Enhanced Interior Gateway Routing Protocol (EIGRP). By contrast, exterior gateway protocols are used to exchange routing information ''between'' autonomous systems and rely on IGPs to resolve routes within an autonomous system. Examples Examples of distance-vector routing protocols: * Routing Information Protocol (RIP) * Routing Information P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Routing
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. In packet switching networks, routing is the higher-level decision making that directs network packets from their source toward their destination through intermediate network nodes by specific packet forwarding mechanisms. Packet forwarding is the transit of network packets from one network interface to another. Intermediate nodes are typically network hardware devices such as routers, gateways, firewalls, or switches. General-purpose computers also forward packets and perform routing, although they have no specially optimized hardware for the task. The routing process usually directs forwarding on the basis of routing tables. Routing tables maintain a record of the routes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CCNA
CCNA (Cisco Certified Network Associate) is an information technology (IT) certification from Cisco Systems. CCNA certification is an associate-level Cisco Career certification. The Cisco exams have changed several times in response to the changing IT trends. In 2020, Cisco announced an update to its certification program that "Consolidated and updated associate level training and certification." Cisco has consolidated the previous different types of Cisco-Certified Network Associate with a general CCNA certification. The content of the exams is proprietary. Cisco and its learning partners offer a variety of different training methods, including books published by Cisco Press, and online and classroom courses available under the title "Interconnecting Cisco Network Devices". Exam To achieve a CCNA certification, candidates must earn a passing score on Cisco exam #200-301. At the completion of the exam, candidates receive a score report along with a score breakdown by exam s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VLSM
Classless Inter-Domain Routing (CIDR ) is a method for allocating IP addresses and for IP routing. The Internet Engineering Task Force introduced CIDR in 1993 to replace the previous classful network addressing architecture on the Internet. Its goal was to slow the growth of routing tables on routers across the Internet, and to help slow the rapid exhaustion of IPv4 addresses. IP addresses are described as consisting of two groups of bits in the address: the most significant bits are the network prefix, which identifies a whole network or subnet, and the least significant set forms the ''host identifier'', which specifies a particular interface of a host on that network. This division is used as the basis of traffic routing between IP networks and for address allocation policies. Whereas classful network design for IPv4 sized the network prefix as one or more 8-bit groups, resulting in the blocks of Class A, B, or C addresses, under CIDR address space is allocated to Internet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IPv4 Address Exhaustion
IPv4 address exhaustion is the depletion of the pool of unallocated IPv4 addresses. Because the original Internet architecture had fewer than 4.3 billion addresses available, depletion has been anticipated since the late 1980s, when the Internet started experiencing dramatic growth. This depletion is one of the reasons for the development and deployment of its successor protocol, IPv6. IPv4 and IPv6 coexist on the Internet. The IP address space is managed globally by the Internet Assigned Numbers Authority (IANA), and by five regional Internet registries (RIRs) responsible in their designated territories for assignment to end users and local Internet registries, such as Internet service providers. The main market forces that accelerated IPv4 address depletion included the rapidly growing number of Internet users, always-on devices, and mobile devices. The anticipated shortage has been the driving factor in creating and adopting several new technologies, including network a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Classless Inter-Domain Routing
Classless Inter-Domain Routing (CIDR ) is a method for allocating IP addresses and for IP routing. The Internet Engineering Task Force introduced CIDR in 1993 to replace the previous classful network addressing architecture on the Internet. Its goal was to slow the growth of routing tables on routers across the Internet, and to help slow the rapid exhaustion of IPv4 addresses. IP addresses are described as consisting of two groups of bits in the address: the most significant bits are the network prefix, which identifies a whole network or subnet, and the least significant set forms the ''host identifier'', which specifies a particular interface of a host on that network. This division is used as the basis of traffic routing between IP networks and for address allocation policies. Whereas classful network design for IPv4 sized the network prefix as one or more 8-bit groups, resulting in the blocks of Class A, B, or C addresses, under CIDR address space is allocated to Internet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subnet Mask
A subnetwork or subnet is a logical subdivision of an IP network. Updated by RFC 6918. The practice of dividing a network into two or more networks is called subnetting. Computers that belong to the same subnet are addressed with an identical most-significant bit-group in their IP addresses. This results in the logical division of an IP address into two fields: the ''network number'' or ''routing prefix'' and the ''rest field'' or ''host identifier''. The ''rest field'' is an identifier for a specific host or network interface. The ''routing prefix'' may be expressed in Classless Inter-Domain Routing (CIDR) notation written as the first address of a network, followed by a slash character (''/''), and ending with the bit-length of the prefix. For example, is the prefix of the Internet Protocol version 4 network starting at the given address, having 24 bits allocated for the network prefix, and the remaining 8 bits reserved for host addressing. Addresses in the range to bel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
