Neighbor Discovery Protocol is employed by IPv6 hosts for a spread of tasks concerning the native space network. additionally, it conjointly works with ICMPv6 to finish variety of operations. the first tasks for NDP ar Router Discovery, Neighbor Discovery and Duplicate Address Discovery. it had been devised primarily attributable to the actual fact that IPv6 doesn't allow broadcasts and thus Arp (Address Resolution Protocol) as used with IPv4 isn't operating.
Router Discovery
Although there's a version of DHCP which will be used with IPv6, another choice is to find the native router will|which may|which might} give data concerning DHCP servers associate degreed conjointly give an address prefix in order that hosts can tack together their own scientific discipline Addresses. once a number is 1st connected to a link it mechanically multicasts a Router Solicitation message to the All Routers multicast cluster address. Any routers active on the link can respond with a Router advertizing message to the All Hosts multicast cluster address. The Router advertizing message will indicate a spread of knowledge.
Contained inside the Router advertizing message is associate degree address prefix or multiple prefixes concerning subnets obtainable on the native link. The Host then is aware of that subnet or subnets ar native and don't want the help of the native router to achieve. The Host will mechanically tack together it's own scientific discipline Address by mistreatment the prefix and EUI-64 rules. This involves adding associate degree EUI-64 interface symbol derived from the interface raincoat Address to the publicised prefix. The Interface symbol portion of the scientific disciplinev6 IP address is employed to spot a novel physical interface on a link. The forty eight bit raincoat address is separated into two x three bytes (24 bits), with the primary three bytes recognize because the OUI (Organisational distinctive Identifier), normally referred to as the seller range. sixteen extra bits ar inserted between the third and fourth computer memory unit, and these bits ar drawn by the hex range FFFE. The U/L bit, being the seventh bit within the high order computer memory unit is ready to a worth of one to point a worldwide Scope. the method of a number mechanically configuring it's scientific discipline Address from the given prefix is thought as unsettled Autoconfiguration. to boot the Router advertizing message conjointly contains the default hop count that Hosts ought to use.
Neighbor Discovery
NDP Hosts will use alternative Solicitation and advertizing Messages to be used with neighboring Hosts, like Neighbor Solicitation and Neighbor advertizing messages:
Neighbor Solicitation messages is employed by Hosts on the computer network to get raincoat addresses of alternative Hosts, that could be a perform provided by Arp with IPv4. The message is distributed to the solicited-node multicast address that's related to a bunch of hosts matching the last vi bits of the address.
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