DELL N3000 User Manual

Configuring IPv6 Routing

There are many conceptual similarities between IPv4 and IPv6 network 

operation. Addresses still have a network prefix portion (network) and a 

device interface specific portion (host). While the length of the network 

portion is still variable, most users have standardized on using a network 

prefix length of 64 bits. This leaves 64 bits for the interface specific portion, 

called an Interface ID in IPv6. Depending upon the underlying link 

addressing, the Interface ID can be automatically computed from the link 

(e.g., MAC address). Such an automatically computed Interface ID is called 

an EUI-64 identifier, which is the interface MAC address with ff:fe inserted in 

the middle.
IPv6 packets on the network are of an entirely different format than 

traditional IPv4 packets and are also encapsulated in a different EtherType 

(86DD rather than 0800 which is used with IPv4). The details for 

encapsulating IPv6 in Ethernet frames are described in RFC2462.
Unlike IPv4, IPv6 does not have broadcasts. There are two types of IPv6 

addresses — unicast and multicast. Unicast addresses allow direct one-to-one 

communication between two hosts, whereas multicast addresses allow one-to-

many communication. Multicast addresses are used as destinations only. 

Unicast addresses will have 00 through fe in the most significant octets and 

multicast addresses will have ff in the most significant octets.

In Dell Networking N2000, N3000, and N4000 series switches software, IPv6 

coexists with IPv4. As with IPv4, IPv6 routing can be enabled on VLAN 

interfaces. Each L3 routing interface can be used for IPv4, IPv6, or both 

simultaneously.
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 RFC4861. Router advertisement is part of the Neighbor 

Discovery process and is required for IPv6. As part of router advertisement, 

Dell Networking N2000, N3000, and N4000 series switches software supports 

stateless auto configuration of end nodes. The switch supports both EUI-64 

interface identifiers and manually configured interface IDs.