Explanation of the IPv6 address assignment using Ethernet.
Explanation of the IPv6 address assignment using Ethernet.
The Network library maintains several IPv6 addresses for the Ethernet network interface:
- Static Address
is used to communicate globally over internet. It is configured manually or via DHCPv6 in stateful mode.
- Dynamic Address
is configured by a Stateless Address Autoconfiguration and also used to communicate globally.
- Link-local Address
is automatically configured from the interface MAC address. The scope of a link-local address is the intercommunication between hosts on the local area network. The link-local address allows IPv6 hosts to communicate when there is no router and no DHCPv6 server available on the local area network (LAN).
The IPv6 addresses for the Ethernet network interface are assigned in several ways:
- Static IPv6
The IPv6 address, subnet prefix length and default gateway are configured manually in the system configuration file. However, it is possible to change the IPv6 address at runtime. The static configuration specifies also a primary and optional secondary DNS server. To make use of the static IPv6 configuration, you need to disable DHCP for IPv6.
- Dynamic Host Configuration Protocol for IPv6 (DHCPv6)
This mode is mostly used. It requires a centralized DHCPv6 server in the local area network (LAN). There are two methods of DHCPv6:
- stateless mode
Only extended information, such as primary and optional secondary DNS server, is obtained from a DHCPv6 server. IPv6 address is not assigned, so the IPv6 address from the Ethernet configuration is set for a Static address of Ethernet interface.
- stateful mode
DHCPv6 server maintains a database of leased IPv6 addresses, and assigns to the client an unused IPv6 address. The DHCPv6 server specifies also a primary and optional secondary DNS server. The DNS server is used to resolve the IP address for a known host name.
- IPv6 Stateless Address Autoconfiguration (SLAAC)
This mode is always used and configures a Dynamic Address. SLAAC provides the ability to address a host based on a network prefix that is advertised from a local network router via Router Advertisements (RA).
- Note
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