Used to set the prefix options for used interfaces. The following settings are possible:
- Interface name
- Defines the name of the logical interface to be used for sending router advertisements.
- Prefix
- Enter a prefix that is announced with router advertisements, e.g. "2001:db8::/64". The prefix length must always be exactly "/64", otherwise it will be impossible for clients to generate their addresses by adding their interface identifiers (with a length of 64 bits). If a prefix delegated by the provider is to be propagated automatically, set "::/64" here and enter the name of the corresponding WAN interface as the parameter Receive prefix from.
- Subnet ID
- Here you enter the subnet ID that is to be combined with the prefix delegated by the provider. If the provider assigns the prefix "2001:db8:a::/48", for example, and the subnet ID is "0001" (or "1" for short), then the router advertisement on this interface is given the prefix "2001:db8:a:0001::/64". The maximum subnet length with a 48-bit long delegated prefix is 16 bits (i.e. 65,536 subnets), with available subnet IDs ranging from "0000" to "FFFF". With a delegated prefix of "/56", the maximum subnet length is 8 bits (i.e. 256 subnets) with subnet IDs ranging from "00" to "FF". In general, the subnet ID "0" is used when the WAN IPv6 address is formed automatically. This is why subnet IDs for LANs start at "1". The default setting is "1".
- Advertise on-link
- Specifies whether this prefix is linked directly to the interface ('on link').
- Allow auto-configuration (SLAAC)
- Specifies whether the prefix is to be used for a stateless address autoconfiguration (SLAAC). The default setting is "enabled".
- Receive prefix from
- Specifies the name of the interface used to receive a prefix via DHCPv6 prefix delegation or tunnel. This prefix can be used to derive and propagate a subnet for each interface.
- Advertise preferred lifetime
- Specifies how long an IPv6 address should be considered as "preferred". If the preferred lifetime of an address has expired, it is marked as "deprecated" and used only for existing sessions, but not for new ones.
- Advertise valid lifetime
- Specifies how long an IPv6 address should be considered as "valid", after which it becomes "invalid" and is discarded.
