Users Guide

IPv6 Routing 1485
Neighbor Discovery (ND) protocol is the IPv6 replacement for Address
Resolution Protocol (ARP) in IPv4. The IPv6 Neighbor Discovery protocol is
described in detail in RFC7048. Dell EMC Networking IPv6 supports
neighbor advertise and solicit, duplicate address detection, and unreachability
detection. Router advertisement is part of the Neighbor Discovery process
and is required for IPv6. As part of router advertisement, Dell EMC
Networking N-Series switch software supports stateless auto configuration of
end nodes. The switch supports both EUI-64 interface identifiers and
manually configured interface IDs.
For ICMPv6, error PDU generation is supported, as are path MTU, echo, and
redirect.
While optional in IPv4, router advertisement is mandatory in IPv6. Router
advertisements specify the network prefix(es) on a link which can be used by
receiving hosts, in conjunction with an EUI-64 identifier, to autoconfigure a
host’s address. Routers have their network prefixes configured and may use
EUI-64 or manually configured interface IDs. In addition to a single global
address and a single unique local address in the fc00::/7 range, each IPv6
interface also has an autoconfigured “link-local” address, which is:
• fe80::/10, with the EUI-64 address in the least significant bits.
• Reachable only on the local VLAN — link-local addresses are never routed.
• Not globally unique
Next hop addresses computed by routing protocols are usually link-local
addresses.
During the period of transitioning the Internet to IPv6, a global IPv6 Internet
backbone may not be available. One transition mechanism is to tunnel IPv6
packets inside IPv4 to reach remote IPv6 islands. When a packet is sent over
such a link, it is encapsulated in IPv4 in order to traverse an IPv4 network and
has the IPv4 headers removed at the other end of the tunnel.