The TCPIP ADDRESS SELECTION POLICY (TCPIP ASP) command enables an administrator to override the default selection behavior as specified by RFC 3484. The administrator can use this command to set up policies to establish which addresses are preferred over other addresses.
For example, an administrator can specify a preferred prefix that can be used to select one source address from other potential candidates assigned to the same interface when communicating with a particular destination prefix. This command can also be used to select destination addresses with higher precedence values over addresses of lower precedence. The command is not valid unless IPv6 has been enabled.
The address selection policy does not override the explicit choice of a legal destination or source address.
This command updates the address selection policy table. However, default address selection using the defined policies does not occur unless the IPv6 default address selection feature has been enabled using the IPv6DAS option of the TCPIP OPT command.
When enabled, default address selection is based on a set of predefined default policies as defined by RFC 3484. These default policies can be deleted, changed, or amended using the TCPIP ADDRESS SELECTION POLICY command.
The default option deletes all entries in the table and restores the table to the RFC definition.
Examples: Setting Precedence and Label Values
When precedence values are set, they can be used for sorting destination addresses. An address with a higher precedence value can be preferred over an address with a lower precedence value.
Label values can also be set to create policies that prefer a particular source address prefix for use with a destination address prefix. The algorithm uses a particular source address with a destination address if their labels match.
The ADDRESS SELECTION POLICY command uses precedence values and label values for sorting addresses as follows.
|
Variable |
Description |
|---|---|
|
precedence |
Used for sorting destination addresses. If precedence (A) is greater than precedence (B), address A has higher precedence than address B and destination address A is preferred over destination address B. Range: 1 to 100 |
|
label |
A value that allows for policies that prefer a particular source address prefix for use with a destination address prefix. If label (S) is equal to label (D), source address S is the preferred address to be used with destination address D. Range: 0 to 10 |
Refer to the Networking Commands and Inquiries Help for additional information on the syntax and usage of the ADDRESS SELECTION POLICY command.
Examples
NW TCPIP ASP
NW TCPIP ASP 090F::9FFF:8998/128
NW TCPIP ASP Add 090F::9FFF:8998/128 90 9
NW TCPIP ASP Add 192.49.59.98/29 80 4
NW TCPIP ASP Add 192.49.59.98/29 80 4, 090F::9FFF:8998/128 90 9
NW TCPIP ASP Delete 192.49.59.98/29
NW TCPIP ASP Modify 192.49.59.98/29 80 4
NW TCPIP ASP Modify 090F::9FFF:8998/128 50 5
