DELL N3000 User Manual

Configuring IPv6 Routing

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 zero or more 

global addresses, 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.

IPv6 is disabled by default on the switch and on all interfaces.
Table 38-1 shows the default values for the IP routing features this chapter 

describes.

IPv6 Unicast Routing Mode

Disabled

IPv6 Hop Limit

Unconfigured

ICMPv6 Rate Limit Error Interval

1000 milliseconds

ICMPv6 Rate Limit Burst Size

100

Interface IPv6 Mode

Disabled