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Lollipop Sequence Numbering
Lollipop sequence numbering is a numbering scheme used in routing protocols. In this numbering scheme, sequence numbers start at a negative value, increase until they reach zero, then cycle through a finite set of positive numbers indefinitely. When a system is rebooted, the sequence is restarted from a negative number again. This allows recently rebooted systems to be distinguished from systems which have simply looped around their numbering space. This path can be visualized as a line with a circle at the end; hence a lollipop. Lollipop sequence numbering was originally believed to resolve the ambiguity problem in cyclic sequence numbering schemes, and was used in OSPF 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 syste ... version 1 for this reason. Later work showed that this was not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Numbering Scheme
There are many different numbering schemes for assigning nominal numbers to entities. These generally require an agreed set of rules, or a central coordinator. The schemes can be considered to be examples of a primary key of a database management system Table (database), table, whose table definitions require a database design. In computability theory, the simplest Numbering (computability theory), numbering scheme is the assignment of natural numbers to a Set (mathematics), set of objects such as function (mathematics), functions, rational numbers, Graph (discrete mathematics), graphs, or words in some formal language. A numbering can be used to transfer the idea of computability and related concepts, which are originally defined on the natural numbers using computable functions, to these different types of objects. A simple extension is to assign cardinal numbers to physical objects according to the choice of some base of reference and of measurement units for counting or measuri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Routing Protocols
A routing protocol specifies how routers communicate with each other to distribute information that enables them to select routes 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 r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lollipop
A lollipop is a type of sugar candy usually consisting of hard candy mounted on a stick and intended for sucking or licking. Different informal terms are used in different places, including lolly, sucker, sticky-pop, etc. Lollipops are available in many flavors and shapes. Types Lollipops are available in a number of colors and flavors, particularly fruit flavors. With numerous companies producing lollipops, the candy now comes in dozens of flavors and many different shapes. Lollipops can range from very small candies bought in bulk and given away as a courtesy at banks, barbershops, and other locations, to very large treats made from candy canes twisted into a spiral shape. Most lollipops are eaten at room temperature, but " ice lollipops", "ice lollies", or "popsicles" are frozen water-based lollipops. Similar confections on a stick made of ice cream, often with a flavored coating, are usually not called by this name. Some lollipops contain fillings, such as bubbl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OSPF
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). OSPF gathers link state information from available routers and constructs a topology map of the network. The topology is presented as a routing table to the Internet Layer for routing packets by their destination IP address. OSPF supports Internet Protocol Version 4 (IPv4) and Internet Protocol Version 6 (IPv6) networks and supports the Classless Inter-Domain Routing (CIDR) addressing model. OSPF is widely used in large enterprise networks. IS-IS, another LSR-based protocol, is more common in large service provider networks. Originally designed in the 1980s, OSPF is defined for IPv4 in protocol version 2 by RFC 2328 (1998)., Updated by RFC 5709, RFC 6549, RFC 6845, RFC 6860, RFC 7474, RFC 8042. The updates for IPv6 are spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ARPANET Sequence Bug
The Advanced Research Projects Agency Network (ARPANET) was the first wide-area packet-switched network with distributed control and one of the first networks to implement the TCP/IP protocol suite. Both technologies became the technical foundation of the Internet. The ARPANET was established by the Advanced Research Projects Agency (ARPA) of the United States Department of Defense. Building on the ideas of J. C. R. Licklider, Bob Taylor initiated the ARPANET project in 1966 to enable access to remote computers. Taylor appointed Larry Roberts as program manager. Roberts made the key decisions about the network design. He incorporated Donald Davies' concepts and designs for packet switching, and sought input from Paul Baran. ARPA awarded the contract to build the network to Bolt Beranek & Newman who developed the first protocol for the network. Roberts engaged Leonard Kleinrock at UCLA to develop mathematical methods for analyzing the packet network technology. The first com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Identifiers
An identifier is a name that identifies (that is, labels the identity of) either a unique object or a unique ''class'' of objects, where the "object" or class may be an idea, physical countable object (or class thereof), or physical noncountable substance (or class thereof). The abbreviation ID often refers to identity, identification (the process of identifying), or an identifier (that is, an instance of identification). An identifier may be a word, number, letter, symbol, or any combination of those. The words, numbers, letters, or symbols may follow an encoding system (wherein letters, digits, words, or symbols ''stand for'' epresentideas or longer names) or they may simply be arbitrary. When an identifier follows an encoding system, it is often referred to as a code or ID code. For instance the ISO/IEC 11179 metadata registry standard defines a code as ''system of valid symbols that substitute for longer values'' in contrast to identifiers without symbolic meaning. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
