IPv6 Configuration

show ipv6 interfaces

[Command]

show ipv6 interfaces

[Purpose]

View IPv6 address information

[View]

System view

[Notes]

The physical state of the interface is admin.

[Use Cases]

sonic# show ipv6 interfaces
Interface    Master    IPv6 address/mask    MAC Address        Admin/Oper
-----------  --------  -------------------  -----------------  ------------
vlan10                 2001::1008/64        60:eb:5a:01:1c:93  up/up

show ndp

[Command]

show ndp

show ndp ipv6-address A::B

show ndp iface {mgmt|ethernet interface_num } ipv6-address A::B

[Purpose]

View IPv6 neighbor table entry information

[View]

System view

[Use Cases]

sonic# show ndp
Address                 MacAddress        Iface       Vlan  Status
---------------------- ----------------- ---------- ------ ---------
2022::9300              18:17:25:37:65:08 Ethernet50   -    REACHABLE
2022::9310              18:17:25:37:67:22 Ethernet49   -    REACHABLE
fd00:400::ae2b          94:e6:f7:25:3b:3b Ethernet11   400  REACHABLE

show nd ipv6 mac-check

[Command]

show nd ipv6 mac-check

[Purpose]

Show IPv6 MAC address detection configuration

[View]

System view

[Use Cases]

sonic# show nd ipv6 mac-check
+-----------+
| enabled   |
+===========+
| false     |
+-----------+

show nd rate-limit

[Command]

show nd rate-limit

[Purpose]

Show ND packets speed limit configuration

[View]

System view

[Use Cases]

sonic# show nd rate-limit
+--------------+
| rate-limit   |
+==============+
| 2000 pps     |
+--------------+

ip address

[Command]

ip address A::B/mask

no ip address A::B/mask

[Purpose]

Specify the IPv6 address of the interface

[Parameter]

Parameter	Description
A::B/mask	Total length is 128 bits in the format

[View]

Interface view

[Use Cases]

sonic# configure terminal
sonic(config)# interface vlan 100
sonic(config-vlanif-100)# ip address fd00::1000/64

ipv6 use-link-local

[Command]

ipv6 use-link-local no ipv6 use-link-local

[Purpose]

Use the interface’s IPv6 link-local address for BGP neighbor session establishment.

[View]

Interface view、lag view

[Use Cases]

sonic# configure terminal
sonic(config)# interface ethernet 1
sonic(config-if-1)# ipv6 use-link-local

nd ra

[Command]

nd ra

no nd ra

[Purpose]

Enable the interface to send RA packets

[View]

System configuration view

[Usage Scenario] Enabling this configuration causes the device to periodically broadcast RA messages. These messages contain information about IPv6 address prefixes and the Autonomous Address Configuration (Autoconfig) flag set to disabled. End-user devices connected to this router will generate IPv6 addresses using stateless configuration methods, as they will not rely on automatic address assignment.

[Use Cases]

sonic# configure terminal
sonic(config)# nd ra

nd ra autonomous {on|off}

[Command]

nd ra autonomous {on|off }

[Purpose]

Set the flag bit of the stateless auto-configuration address in the RA packets

[View]

Vlan view, System configuration view

[Notes]

The default state is off, and the flag bit is 0.

[Use Cases]

sonic# configure terminal
sonic(config)# vlan 100
sonic(config-vlan-100)# nd ra autonomous on

nd ra dns-server

[Command]

nd ra dns-server A::B no nd ra dns-server A::B

[Purpose]

Set the DNS server address in the RA packets

[View]

Vlan view, System configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# vlan 100
sonic(config-vlan-100)# nd ra dns-server 2400:3200:baba::1

nd ra link-mtu

[Command]

nd ra link-mtu mtu

[Purpose]

Set the link_mtu in the RA packet

[Parameter]

Parameter	Description
mtu	Value range 0/1280-1500

[View]

Vlan view, System configuration view

[Usage Scenario] When enabled, this configuration specifies that the device includes an MTU option in its Router Advertisement (RA) messages. The value of the MTU option should match the MTU configured on the interface. Hosts receiving these RA messages will adjust the size of their transmitted packets based on the provided MTU value.

[Use Cases]

sonic# configure terminal
sonic(config)# vlan 100
sonic(config-vlan-100)# nd ra link-mtu 1500

nd ra managed-flag

[Command]

nd ra managed-flag {on|off}

[Purpose]

Set the flag bit of the stateful auto-configuration address in RA packet (FLAG M)

[View]

Vlan view, System configuration view

[Usage Scenario] The managed-flag in an RA (Router Advertisement) message for IPv6 is a flag that indicates whether hosts receiving the RA message should use DHCPv6 (Dynamic Host Configuration Protocol for IPv6) to obtain additional network configuration information, such as IPv6 addresses, DNS servers, and more. When the managed-flag is set to 1 in an RA message, it means that hosts receiving this message should use DHCPv6 to acquire IPv6 addresses and other configuration information. This is typically used in specific network deployment scenarios where more fine-grained address management or specific network policies are required. If the managed-flag is set to 0, then hosts receiving the RA message can use automatic configuration methods, such as SLAAC (Stateless Address Autoconfiguration), to generate IPv6 addresses without the need for DHCPv6. This is suitable for many typical IPv6 network deployments, where DHCPv6 is primarily used for distributing other configuration options rather than assigning IPv6 addresses.

[Use Cases]

sonic# configure terminal
sonic(config)# vlan 100
sonic(config-vlan-100)# nd ra managed-flag on

nd ra other-flag

[Command]

nd ra other-flag {on|off}

[Purpose]

Set the flag bit for stateful auto-configuration of other information in RA packet (FLAG O)

[View]

Vlan view, System configuration view

[Usage Scenario] The “O” flag, which stands for the “other-flag” field in IPv6 Router Advertisement (RA) messages, is used to indicate whether hosts receiving the RA message should use other protocols for configuration. When the “O” flag (other-flag) in an RA message is set to 1, it means that hosts receiving this message should use other protocols to obtain additional network configuration information instead of using DHCPv6. This other protocol could be a custom protocol specific to the network environment or another configuration protocol. Setting the “O” flag allows network administrators to specify how hosts should obtain additional configuration information in special situations, not limited to the use of DHCPv6 or SLAAC. If the “O” flag is set to 0, then hosts receiving the RA message can follow standard IPv6 auto-configuration methods like SLAAC to generate IPv6 addresses, or they can use DHCPv6 to obtain configuration information, depending on the setting of the managed-flag field.

[Use Cases]

sonic# configure terminal
sonic(config)# vlan 100
sonic(config-vlan-100)# nd ra other-flag on

nd ra prefix

[Command]

nd ra prefix A::B/mask

no nd ra prefix A::B/mask

[Purpose]

Set the prefix information in RA packet

[Parameter]

Parameter	Description
A::B/mask	The format is X:X:X:X:X:X:X:X/x

[View]

Vlan view, System configuration view

[Usage Scenario] In the default configuration, Router Advertisement (RA) messages do not automatically include address prefixes; you need to specify them manually. When a host receives an RA message that carries prefix information, it will update its local prefix information accordingly..

[Use Cases]

sonic# configure terminal
sonic(config)# vlan 100
sonic(config-vlan-100)# nd ra prefix fd00:100::/64

nd ra route-information

[Command]

nd ra route-information A::B/mask [preference {low|medium|high}]

no nd route-information A::B/mask

[Purpose]

Set the routing option information in RA packet

[Parameter]

Parameter	Description
A::B/mask	The format is X:X:X:X:X:X:X:X/x

[View]

Vlan view, System configuration view

[Usage Scenario] The RA packet contains routing option information, through which the device will publish specific routing information to the hosts of this segment. By default, the routing priority is medium.

[Use Cases]

sonic# configure terminal
sonic(config)# vlan 100
sonic(config-vlan-100)# nd ra route-information fd00:100::/64
sonic(config-vlan-100)# nd ra route-information ::/0 preference high

nd rate-limit

[Command]

nd rate-limit value

[Purpose]

Configure the device’s speed limit policy for IPv6 NDP interaction packet, by default, the speed limit rate is 2000pps

[Parameter]

Parameter	Description
value	Value range: 100-1000, precision: 100, unit: pps

[View]

System configuration view

[Use Cases]

sonic(config)# nd rate-limit 1000

nd ipv6 mac-check enable

[Command]

nd ipv6 mac-check enable

no nd ipv6 mac-check enable

[Purpose]

Enable detection of the legitimacy of ND interaction packet

[View]

System configuration view

[Usage Scenario] Detect whether the link-layer address and SMAC of the NDP interaction packet are the same, and if they are different, they are regarded as illegal packet.

[Use Cases]

sonic(config)# nd ipv6 mac-check enable