5.2. NDP Commands

Command Purpose

Use this command to configure a static neighbor entry.

To delete the static neighbor entry, user the no form of this command.

Prerequisites

Command Syntax

ipv6 neighbor ( vrf NAME | ) IPV6_ADDR MAC ( IFNAME | )

no ipv6 neighbor ( vrf NAME | ) IPV6_ADDR ( IFNAME | )

Command Mode

Global Config

Default

By default, there is not any static ipv6 neighbor entry exist.

Usage

Use this command to configure a static neighbor entry. If the IPv6 address is link-local, the interface name must be specified.

Using the no form of this command should not remove any dynamic neighbor entries.

Examples

This example shows how to add a static neighbor entry:

Switch# configure terminal
Switch(config)# ipv6 neighbor 2001::1 0000.0000.0001
Switch(config)# ipv6 neighbor vrf a fe80::1 0000.0000.0002 eth-0-1

Related Commands

show ipv6 neighbors

Command Purpose

Use this command to clear the dynamic neighbor entries.

Prerequisites

Command Syntax

clear ipv6 neighbors ( vrf NAME | ) ( interface IFNAME | )

clear ipv6 neighbors ( vrf NAME | ) IPV6_ADDR ( interface IFNAME | )

Command Mode

Privileged EXEC

Default

None

Usage

Use this command to clear the dynamic neighbor entries.

User can clear dynamic ipv6 address by interface or address. If the specified address is link-local, the interface is required.

Examples

This example shows how to clear the neighbor entries:

Switch# clear ipv6 neighbors

Related Commands

show ipv6 neighbors

Command Purpose

Use this command to set the ipv6 hop limit of the packets.

To restore the default configuration, use the no form of this command.

Prerequisites

Command Syntax

ipv6 hop-limit HOP_LIMIT

no ipv6 hop-limit

Command Mode

Global Config

Default

By default, the value is 64.

Usage

The hop limit setting should affect all IPv6 packets send from this device, unless the hop-limit is overwritten by up layer application, for example, OSPF, etc.

Examples

This example shows how to set the hop limit:

Switch# configure terminal
Switch(config)# ipv6 hop-limit 255

Related Commands

None

Command Purpose

Use this command to set the “Current hop limit” in RA packets.

To restore the default configuration, use the no form of this command.

Prerequisites

Command Syntax

ipv6 nd ra hop-limit HOP_LIMIT

no ipv6 nd ra hop-limit

Command Mode

Interface Configuration

Default

By default, the value is 0.

Usage

None

Examples

This example shows how to set the “Current hop limit” in RA packets:

Switch# configure terminal
Switch(config)# interface eth-0-1
Switch(config-if)# ipv6 nd ra hop-limit 255

Related Commands

None

Command Purpose

Use this command to set the attempt times of DAD (Duplicate Address Detect).

To restore the default configuration, use the no form of this command.

Prerequisites

Command Syntax

ipv6 nd dad attempts DAD_ATTEMPTS

no ipv6 nd dad attempts

Command Mode

Interface Configuration

Default

By default, the value is 1.

Usage

Use this command to set the attempt times of DAD (Duplicate Address Detect). “0” means DAD feature is disabled

Examples

This example shows how to set the dad attempt:

Switch# configure terminal
Switch(config)# interface eth-0-1
Switch(config-if)# ipv6 nd dad attempts 3

Related Commands

None

Command Purpose

Use this command to set the interval of NS packets.

To restore the default configuration, use the no form of this command.

Prerequisites

Command Syntax

ipv6 nd ns-interval NS_INTERVAL

no ipv6 nd ns-interval

Command Mode

Interface Configuration

Default

By default, the value is 1000

Usage

This configuration should affect the interval of NS packet during the DAD period or neighbor discovery period.

Examples

This example shows how to set the ns interval:

Switch# configure terminal
Switch(config)# interface eth-0-1
Switch(config-if)# ipv6 nd ns-interval 2000

Related Commands

None

Command Purpose

Use this command to enable the RA suppress function.

To disable this function, use the no form of this command.

Prerequisites

Command Syntax

ipv6 nd ra suppress

no ipv6 nd ra suppress

Command Mode

Interface Configuration

Default

By default, RA suppress is enabled.

Usage

When RA suppress function is enabled, no RA/RS packet should be sent from this interface even a RS packet is received.

Examples

This example shows how to enable the RA suppress function:

Switch# configure terminal
Switch(config)# interface eth-0-1
Switch(config-if)# ipv6 nd ra suppress

This example shows how to disable the RA suppress function:

Switch# configure terminal
Switch(config)# interface eth-0-1
Switch(config-if)# no ipv6 nd ra suppress

Related Commands

ipv6 nd ra interval

ipv6 nd ra lifetime

Command Purpose

Use this command to enable the RA MTU suppress function.

To disable this function, use the no form of this command.

Prerequisites

Command Syntax

ipv6 nd ra mtu suppress

no ipv6 nd ra mtu suppress

Command Mode

Interface Configuration

Default

By default, RA MTU suppress is disabled.

Usage

When RA MTU suppress function is enabled, no MTU option should be sent in the RA packets from this interface.

Examples

This example shows how to enable the RA MTU suppress function:

Switch# configure terminal
Switch(config)# interface eth-0-1
Switch(config-if)# ipv6 nd ra mtu suppress

This example shows how to disable the RA MTU suppress function:

Switch# configure terminal
Switch(config)# interface eth-0-1
Switch(config-if)# no ipv6 nd ra mtu suppress

Related Commands

None

Command Purpose

Use this command to set the interval of the RA packets.

To restore the default configuration, use the no form of this command.

Prerequisites

Command Syntax

ipv6 nd ra interval MAX ( MIN | )

no ipv6 nd ra interval

Command Mode

Interface Configuration

Default

By default, MAX interval should be 600 second; MIN interval should be 0.33*MAX.

Usage

The valid range should be between 4 and 1800 second for the max value. The valid range should be between 3 and 0.75 * MAX for the minimum value.

If the minimum value is not specified, it should be 0.33*MAX when MAX >= 9, and it should be equal to the MAX when MAX < 9.

Examples

This example shows how to set the RA interval:

Switch# configure terminal
Switch(config)# interface eth-0-1
Switch(config-if)# ipv6 nd ra interval 300

Related Commands

ipv6 nd ra suppress

ipv6 nd ra lifetime

Command Purpose

Use this command to set the life time of the RA packets.

To restore the default configuration, use the no form of this command.

Prerequisites

Command Syntax

ipv6 nd ra lifetime LIFE_TIME

no ipv6 nd ra lifetime

Command Mode

Interface Configuration

Default

By default, RA life time is 3* MAX RA interval.

Usage

None

Examples

This example shows how to set the ra life time:

Switch# configure terminal
Switch(config)# interface eth-0-1
Switch(config-if)# ipv6 nd ra lifetime 1000

Related Commands

ipv6 nd ra suppress

ipv6 nd ra interval

Command Purpose

Use this command to set reachable time of the neighbor entries.

To restore the default configuration, use the no form of this command.

Prerequisites

Command Syntax

ipv6 nd reachable-time REACHABLE_TIME

no ipv6 nd reachable-time

Command Mode

Interface Configuration

Default

By default, the value is 30000 ms

Usage

A reachable time 0 means to restore the default value 30000.

After the reachable time expired, the neighbor entries which state is “REACH” should change to “STALE”.

Examples

This example shows how to set the reachable time:

Switch# configure terminal
Switch(config)# interface eth-0-1
Switch(config-if)# ipv6 nd reachable-time 3600000

Related Commands

None

Command Purpose

Use this command to set “Managed address configuration” flag.

To unset this configuration, use the no form of this command.

Prerequisites

Command Syntax

ipv6 nd managed-config-flag

no ipv6 nd managed-config-flag

Command Mode

Interface Configuration

Default

By default, the “Managed address configuration” is not set.

Usage

None

Examples

This example shows how to set the “Managed address configuration” flag:

Switch# configure terminal
Switch(config)# interface eth-0-1
Switch(config-if)# ipv6 nd managed-config-flag

Related Commands

ipv6 nd other-config-flag

Command Purpose

Use this command to set the “Other configuration” flag.

To unset this configuration, use the no form of this command.

Prerequisites

Command Syntax

ipv6 nd other-config-flag

no ipv6 nd other-config-flag

Command Mode

Interface Configuration

Default

By default, the “Other configuration” flag is not set.

Usage

None

Examples

This example shows how to set the “Other configuration” flag:

Switch# configure terminal
Switch(config)# interface eth-0-1
Switch(config-if)# ipv6 nd other-config-flag

Related Commands

ipv6 nd managed-config-flag

Command Purpose

Use this command to set prefix for route advertise (RA).

To unset a prefix to advertise, use the no form of this command.

Prerequisites

Command Syntax

ipv6 nd prefix IPv6_PREFIX ( VALID_TIME | infinite ) ( PERFERRED_TIME | infinite ) ( { off-link | no-autoconfig } | )

no ipv6 nd prefix IPv6_PREFIX

ipv6 nd prefix default ( VALID_TIME | infinite ) ( PERFERRED_TIME | infinite ) ( { off-link | no-autoconfig } | )

no ipv6 nd prefix default

Command Mode

Interface Configuration

Default

The valid range of valid life time should be between 0 and 4294967295 seconds. User can also use the keyword “infinite” to indicate the value 4294967295(0xFFFFFFFFUnicodeFF09. The default value should be 2592000 seconds (30 days).

The valid range of preferred life time should be between 0 and 4294967295 seconds. User can also use the keyword “infinite” to indicate the value 4294967295UnicodeFF080xFFFFFFFFUnicodeFF09. The default value should be 604800 seconds (7 days).

Usage

None

Examples

This example shows how to set the prefix:

Switch# configure terminal
Switch(config)# interface eth-0-1
Switch(config-if)# ipv6 nd prefix 2001::1/64 3000 3000

Related Commands

show ipv6 interface IFNAME prefix

Command Purpose

Use this command to show the prefix for route advertise (RA) on the specified interface.

Prerequisites

Command Syntax

show ipv6 interface IFNAME prefix

Command Mode

Privileged EXEC

Default

None

Usage

None

Examples

This example shows the result of this command:

Switch# show ipv6 interface eth-0-1 prefix

Related Commands

ipv6 nd prefix

Command Purpose

Use this command to show all ipv6 neighbor entries.

Prerequisites

Command Syntax

show ipv6 neighbors ( dynamic | static | interface IFNAME | IPV6_ADDR | statistics | )

Command Mode

Privileged EXEC

Default

None

Usage

Neighbor entries should be able to show globally, by interface, or by prefix. Dynamic and static entries can be displayed separately.

Examples

This example shows the result of this command:

Switch# show ipv6 neighbors
IPv6 address Age Link-Layer Addr State Interface
2001::2 7 40f2.fd60.ac00 REACH eth-0-9
fe80::42f2:fdff:fe60:ac00 6 40f2.fd60.ac00 STALE eth-0-9

Related Commands

ipv6 neighbor

Command Purpose

Use this command to open the debug of ipv6 ND feature.

To close the debug of ipv6 ND feature, use the no form of this command.

Prerequisites

Command Syntax

debug ipv6 nd ( packet | events | error | dump | info | all )

no debug ipv6 nd ( packet | events | error | dump | info | all )

Command Mode

Privileged EXEC

Default

By default, the ipv6 nd debug is closed.

Usage

None

Examples

This example shows how to open the ipv6 ND debug:

Switch# debug ipv6 nd all
Switch# terminal monitor

Related Commands

None