IPv4 Residual Deployment
   HOME
*





IPv4 Residual Deployment
IPv4 Residual Deployment (4rd) is an IPv6 transition mechanism for Internet service providers for deployment of Internet Protocol version 6 (IPv6), while maintaining IPv4 service to customers. The protocol and sample applications are specified in RFC 7600. Features IPv4 Residual Deployment has three main features: *Mesh topology: between two endpoints, IPv4 packets take the same direct routes as IPv6 packets. *Shared IPv4 addresses: to deal with the unavoidable IPv4-address shortage, several customers can be assigned a common IPv4 address, with disjoint TCP/UDP port sets assigned to each (an application of the general A+P model of RFC 6346). *Stateless operation: conversions of IPv4 packets into IPv6 packets at domain entry, and the reverse at domain exit, are stateless (i.e., one where ''no per-customer state'' is needed in domain edge nodes). Compared to other IETF-specified mechanisms having the same main features, i.e., MAP-E (RFC 7597, RFC 7598, RFC 2473) and MAP-T (RFC ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

IPv6 Transition Mechanism
An IPv6 transition mechanism is a technology that facilitates the transitioning of the Internet from the Internet Protocol version 4 (IPv4) infrastructure in use since 1983 to the successor addressing and routing system of Internet Protocol Version 6 (IPv6). As IPv4 and IPv6 networks are not directly interoperable, transition technologies are designed to permit hosts on either network type to communicate with any other host. To meet its technical criteria, IPv6 must have a straightforward transition plan from the current IPv4. The Internet Engineering Task Force (IETF) conducts working groups and discussions through the IETF Internet Drafts and Request for Comments processes to develop these transition technologies towards that goal. Some basic IPv6 transition mechanisms are defined in RFC 4213. Stateless IP/ICMP Translation Stateless IP/ ICMP Translation (SIIT) translates between the packet header formats in IPv6 and IPv4. The SIIT method defines a class of IPv6 addresses cal ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Internet Service Providers
An Internet service provider (ISP) is an organization that provides services for accessing, using, or participating in the Internet. ISPs can be organized in various forms, such as commercial, community-owned, non-profit, or otherwise privately owned. Internet services typically provided by ISPs can include Internet access, Transit (Internet), Internet transit, domain name registration, Web hosting service, web hosting, Usenet service, and colocation centre, colocation. An ISP typically serves as the access point or the Default gateway, gateway that provides a user access to everything available on the Internet. Such a network can also be called as an eyeball network. History The Internet (originally ARPAnet) was developed as a network between government research laboratories and participating departments of universities. Other companies and organizations joined by direct connection to the Internet backbone, backbone, or by arrangements through other connected companies, so ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

IPv6
Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP), the communication protocol, communications protocol that provides an identification and location system for computers on networks and routes traffic across the Internet. IPv6 was developed by the Internet Engineering Task Force (IETF) to deal with the long-anticipated problem of IPv4 address exhaustion, and is intended to replace IPv4. In December 1998, IPv6 became a Draft Standard for the IETF, which subsequently ratified it as an Internet Standard on 14 July 2017. Devices on the Internet are assigned a unique IP address for identification and location definition. With the rapid growth of the Internet after commercialization in the 1990s, it became evident that far more addresses would be needed to connect devices than the IPv4 address space had available. By 1998, the IETF had formalized the successor protocol. IPv6 uses 128-bit addresses, theoretically allowing 2128, or approximatel ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Address Plus Port
The Address plus Port (A+P) within the network layer communications protocol for Internet networking is an experimental approach to the IPv4 address shortage. It is a technique for sharing single IPv4 addresses among several users without using stateful network address translation (NAT) in the carrier network. Normal routing only uses the IPv4 address to identify which host an IP packet is destined for. A+P uses the destination TCP or UDP port in addition to the IP address to extend the range of available host addresses. Each host is assigned a unique range of ports which they set as the source port in outbound packets and which they use to receive inbound traffic. A+P is a stateless alternative to conventional stateful NAT, as the A+P gateway does not need to keep track of every TCP or UDP flow. However, it does require A+P aware software at the end-point, capable of limiting the range of port numbers used for originating connections to its allocated range, either in the end ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Internet Engineering Task Force
The Internet Engineering Task Force (IETF) is a standards organization for the 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, an international non-profit organization. Organization The IETF is organized into a large number of working groups and birds of a feather informal discussion groups, each dealing with a specific topic. The IETF operates in a bottom-up task creation mode, largely driven by these working groups. Each working group has an appointed chairperson (or sometimes several co-chairs); a charter that describes its focus; and what it is expected to produce, and when. It is open to all who want to particip ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Path MTU Discovery
Path MTU Discovery (PMTUD) is a standardized technique in computer networking for determining the maximum transmission unit (MTU) size on the network path between two Internet Protocol (IP) hosts, usually with the goal of avoiding IP fragmentation. PMTUD was originally intended for routers in Internet Protocol Version 4 (IPv4). However, all modern operating systems use it on endpoints. In IPv6, this function has been explicitly delegated to the end points of a communications session. As an extension to the standard path MTU discovery, a technique called ''Packetization Layer Path MTU Discovery'' works without support from ICMP. Implementation For IPv4 packets, Path MTU Discovery works by setting the ''Don't Fragment'' (DF) flag bit in the IP headers of outgoing packets. Then, any device along the path whose MTU is smaller than the packet will drop it, and send back an Internet Control Message Protocol (ICMP) ''Fragmentation Needed'' (Type 3, Code 4) message containing its MTU, ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  




Access Control Lists
In computer security, an access-control list (ACL) is a list of permissions associated with a system resource (object). An ACL specifies which users or system processes are granted access to objects, as well as what operations are allowed on given objects. 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. 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 specific system objects such as programs, processes, or files. These entries are known as access-control entries (ACEs) in the Microsoft Windows NT, OpenVMS, and Unix-like operating systems ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Web Caches
A Web cache (or HTTP cache) is a system for optimizing the World Wide Web. It is implemented both client-side and server-side. The caching of multimedias and other files can result in less overall delay when browsing the Web. Parts of the system Forward and reverse A forward cache is a cache outside the web server's network, e.g. in the client's web browser, in an ISP, or within a corporate network. A network-aware forward cache only caches heavily accessed items. A proxy server sitting between the client and web server can evaluate HTTP headers and choose whether to store web content. A reverse cache sits in front of one or more web servers, accelerating requests from the Internet and reducing peak server load. This is usually a content delivery network (CDN) that retains copies of web content at various points throughout a network. HTTP options The Hypertext Transfer Protocol (HTTP) defines three basic mechanisms for controlling caches: freshness, validation, and invalidati ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Deep Packet Inspection
Deep packet inspection (DPI) is a type of data processing that inspects in detail the data being sent over a computer network, and may take actions such as alerting, blocking, re-routing, or logging it accordingly. Deep packet inspection is often used to baseline application behavior, analyze network usage, troubleshoot network performance, ensure that data is in the correct format, check for malicious code, eavesdropping, and internet censorship, among other purposes. There are multiple headers for IP packets; network equipment only needs to use the first of these (the IP header) for normal operation, but use of the second header (such as TCP or UDP) is normally considered to be shallow packet inspection (usually called stateful packet inspection) despite this definition. There are multiple ways to acquire packets for deep packet inspection. Using port mirroring (sometimes called Span Port) is a very common way, as well physically inserting a network tap which duplicates an ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Customer-premises Equipment
In telecommunications, a customer-premises equipment or customer-provided equipment (CPE) is any terminal and associated equipment located at a subscriber's premises and connected with a carrier's telecommunication circuit at the demarcation point ("demarc"). The demarc is a point established in a building or complex to separate customer equipment from the equipment located in either the distribution infrastructure or central office of the communications service provider. CPE generally refers to devices such as telephones, routers, network switches, residential gateways (RG), set-top boxes, fixed mobile convergence products, home networking adapters and Internet access gateways that enable consumers to access providers' communication services and distribute them in a residence or enterprise with a local area network (LAN). A CPE can be an active equipment, as the ones mentioned above, or passive equipment such as analogue telephone adapters (ATA) or xDSL-splitters. This inc ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

IPv6 Rapid Deployment
6rd is a mechanism to facilitate IPv6 rapid deployment across IPv4 infrastructures of Internet service providers (ISPs). It is derived from 6to4, a preexisting mechanism to transfer IPv6 packets over the IPv4 network, with the significant change that it operates entirely within the end-user's ISP's network, thus avoiding the major architectural problems inherent in the original design of 6to4. The name 6rd is a reference to both the rapid deployments of IPv6 it makes possible and, informally, the initials (RD) of its inventor, Rémi Després. A description of 6rd principles and of how they were first used by Free is published in RFC 5569.RFC 5569 IPv6 Rapid Deployment on IPv4 Infrastructures (6rd) The detailed 6rd specification prepared for standardization in the IETF is available as RFC 5969.RFC 5969 IPv6 Rapid Deployment on IPv4 Infrastructures (6rd) -- Protocol Specification History In November 2007, Rémi Després — who was one of the creators of the Transpac data ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Stateless IP/ICMP Translation
An IPv6 transition mechanism is a technology that facilitates the transitioning of the Internet from the Internet Protocol version 4 (IPv4) infrastructure in use since 1983 to the successor addressing and routing system of Internet Protocol Version 6 (IPv6). As IPv4 and IPv6 networks are not directly interoperable, transition technologies are designed to permit hosts on either network type to communicate with any other host. To meet its technical criteria, IPv6 must have a straightforward transition plan from the current IPv4. The Internet Engineering Task Force (IETF) conducts working groups and discussions through the IETF Internet Drafts and Request for Comments processes to develop these transition technologies towards that goal. Some basic IPv6 transition mechanisms are defined in RFC 4213. Stateless IP/ICMP Translation Stateless IP/ ICMP Translation (SIIT) translates between the packet header formats in IPv6 and IPv4. The SIIT method defines a class of IPv6 addresses ca ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]