prefix-assign-mode

Function

The prefix-assign-mode command configures the IPv6 prefix allocation mode to be the unshared mode. That is, IPv6 users do not share the same IP prefix.

The undo prefix-assign-mode command restores the default configuration.

By default, the IP prefix allocation mode is the shared mode.

This command is supported only on the NetEngine 8000 F1A.

Format

prefix-assign-mode unshared

undo prefix-assign-mode

Parameters

None

Views

AAA domain view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
aaa-access	write

Usage Guidelines

Usage Scenario

In shared ND address allocation mode, RS packets sent by clients to a device server will carry interface IDs. The device server allocates only IPv6 prefixes to clients. The device server generates UNR routes based on the IPv6 prefixes and interface IDs. If the interface IDs change automatically, the NetEngine 8000 F server cannot obtain correct UNR routes. As a result, users cannot go online. In unshared ND address allocation mode, the device server generates UNR routes based only on IPv6 prefixes. Therefore, if the interface IDs change automatically, you must run the prefix-assign-mode unshared command to configure the IPv6 prefix allocation mode to be the unshared mode.

In DHCPv6 address allocation mode, clients obtain complete IPv6 addresses which do not change. The device server generates UNR routes based on the IPv6 addresses. Therefore, this command does not take effect for DHCPv6 users.

In ND address allocation mode, interface IDs in the global unicast IP addresses of PCs running Windows7 operating system may change automatically. In DHCPv6 address allocation mode, interface IDs in the global unicast IP addresses of PCs do not change.

Precautions

In VS mode, this command is supported only by the admin VS.

This command is valid only when addresses are assigned through ND.
In scenarios where addresses are assigned through ND, if the shared mode is used, the local address pool must be used. If the exclusive mode is used, you need to run the prefix-assign-mode unshared command in the domain view and use the delegation address pool to assign prefixes. The prefix length must be 64 bits. Otherwise, users cannot obtain IPv6 prefixes.
If prefixes are assigned through ND, users cannot be triggered to go online through NS/NA/IPv6 packets after they go offline unexpectedly.

Example

# Configure the IP prefix allocation mode to be the unshared mode in the domain named huawei.

<HUAWEI> system-view
[~HUAWEI] aaa
[~HUAWEI-aaa] domain huawei
[*HUAWEI-aaa-domain-huawei] commit
[~HUAWEI-aaa-domain-huawei] prefix-assign-mode unshared