Configuring IP Router Parameters
30 7705 SAR OS Router Configuration Guide
Neighbor Discovery
IPv6 provides autoconfiguration of addresses, where equipment connecting to an IPv6
network can autoconfigure a usable address. There are two types of address
autoconfiguration: stateless and stateful. Stateless autoconfiguration requires no manual
configuration of hosts, minimal configuration of routers, and no servers. The host generates
its own addresses using locally available information and information advertised by routers,
such as the 7705 SAR. Stateless autoconfiguration is a feature of the neighbor discovery
protocol.
Stateful autoconfiguration involves hosts obtaining interface addresses and/or configuration
information from a server. For more information on stateful configuration, see DHCP Relay
and DHCPv6 Relay.
Stateless autoconfiguration uses two neighbor discovery messages: router solicitation and
router advertisement. The host sends router solicitation messages to find routers, and the
routers send router advertisement messages to indicate their presence. The host sends the
router solicitation message to all routers, requesting the IPv6 prefix as well as the IPv6
address of the routers. Each router responds with a router advertisement message indicating
their IPv6 prefix and IPv6 address.
Next Header 8-bit selector that identifies the type of header
immediately following the IPv6 header. The Next
Header uses the same values as the IPv4 protocol
field for some protocols; for example, the values
for TCP and UDP are the same for both IPv4 and
IPv6.
The Next Header values differ from IPv4 when
IPv6 extension headers are identified or when IPv6
unique protocols, such as ICMPv6, are identified.
Hop Limit 8-bit unsigned integer that is decremented by 1 by
each node that forwards the packet. If the hop limit
is decremented to 0, the packet is discarded and the
node sends the ICMPv6 message “Hop Limit
Exceeded in transit” back to the sender.
Source Address 128-bit address of the originator of the packet
Destination Address 128-bit address of the intended recipient of the
packet
Table 2: IPv6 Header Field Descriptions (Continued)
Field Description
To Next Page
Loading...
