isis ipv6 bfd block

Function

The isis ipv6 bfd block command disables an interface from dynamically establishing an IPv6 BFD session.

The undo isis ipv6 bfd block command cancels the configuration.

By default, no interface is disabled from dynamically establishing a BFD session.

Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support this command.

Format

isis ipv6 bfd block

undo isis ipv6 bfd block

Parameters

None

Views

Interface view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

If the ipv6 bfd all-interfaces enable command is run in an IS-IS process, IPv6 BFD for IS-IS is enabled on all IS-IS interfaces that are associated with this IS-IS process. You can run the isis ipv6 bfd block command to disable an interface from dynamically establishing an IPv6 BFD session.

Prerequisites

To make the isis ipv6 bfd block command take effect, do as follows first:

Enable IPv6 globally in the system view by using the ipv6 command.
Enable an IS-IS process by using the isis command.
Enable IPv6 capability of the IS-IS process by using the ipv6 enable command in the IS-IS view.
On each interface that runs an IS-IS process, enable IPv6 capability by using the ipv6 enable command.
Enable IS-IS on each interface by using the isis ipv6 enable command.

Precautions

The isis ipv6 bfd block command and the isis ipv6 bfd enable command are mutually exclusive and cannot be run on the same interface.

The function of the isis ipv6 bfd block command is similar to the function of the undo isis ipv6 bfd enable command, except that:

After the undo isis ipv6 bfd enable command is configured on an IS-IS interface, if the ipv6 bfd all-interfaces enable command is reconfigured in the IS-IS view, the interface still has IPv6 BFD for IS-IS capabilities.
After the isis ipv6 bfd block command is configured on an IS-IS interface, the interface does not have IPv6 BFD for IS-IS capabilities, even if the ipv6 bfd all-interfaces enable command is reconfigured in the IS-IS view.

To enable IPv6 BFD for IS-IS on most IS-IS interfaces, you need to configure the isis ipv6 bfd block command on the IS-IS interfaces that do not need to be enabled with IPv6 BFD for IS-IS, and then configure the ipv6 bfd all-interfaces enable command in the IS-IS view.
To enable IPv6 BFD for IS-IS only on a few IS-IS interfaces, configure the isis ipv6 bfd enable command on these interfaces. In this situation, you can configure the undo isis ipv6 bfd enable or isis ipv6 bfd block command to disable IPv6 BFD for IS-IS on these interfaces.

Example

# Disable Vlanif10 from dynamically establishing an IPv6 BFD session.

<HUAWEI> system-view
[HUAWEI] ipv6
[HUAWEI] isis
[HUAWEI-isis-1] ipv6 enable
[HUAWEI-isis-1] quit
[HUAWEI] interface vlanif10
[HUAWEI-Vlanif10] ipv6 enable
[HUAWEI-Vlanif10] isis ipv6 enable
[HUAWEI-Vlanif10] isis ipv6 bfd block