IPv6 Service Configuration Guide

Introduction

Internet Protocol version 6 (IPv6), also called IP Next Generation (IPng), is a second-generation network layer protocol and an upgraded version of Internet Protocol version 4 (IPv4). It is designed by the Internet Engineering Task Force (IETF).

Configure the IPv6 address of the interface

Table 1 Configure IPv6 address of the interface

Purpose	Commands	Description
Enter global configuration view.	configure terminal	-
Create interface configuration view.	interface {ethernet interface-name[.subinterface-number] | link-aggregation lag-id[.subinterface-number] | vlan vlan-id | loopback loopback-id | mgmt 0}	-
Configure an IPv6 address of the interface.	ip address A::B/M	IPv6 address with subnet mask /127 or /128 is not allowed to be configured. In other subnet masks, addresses with the host portion all-zeros are not allowed, but all-ones are allowed.

Tip

NOTE: For the Ethernet ports, LAGIFs and VLANIFs, the ipv6 use-link-local attribute will be enabled automatically after configuring an IPv6 address, that is, the IPv6 link-local address will be generated automatically.

Enable auto-generation of IPv6 link-local address for interfaces

IPv6 link-local addresses are commonly used for neighbor discovery protocols and stateless autoconfiguration. There are two ways to generate:

• Auto-generation The device automatically generates a link-local address for an interface based on the link-local address prefix (FE80::/10) and the link-layer address of the interface.
• Manual Assignment Users manually configure the IPv6 link-local address via the method described in Configure the IPv6 address of the interface It is recommended to use the auto-generation method to avoid link-local address conflicts.

Table 2 Enable auto-generation of IPv6 link-local address for interfaces

Purpose	Commands	Description
Enter global configuration view.	configure terminal	-
Create interface configuration view.	interface {ethernet interface-name [.subinterface-number] | link-aggregation lag-id[.subinterface-number] | vlan vlan-id}	-
Enable auto generation of IPv6 link-local address.	ipv6 use-link-local	-

Display and Maintenance

Table 3 IPv6 display and maintenance

Purpose	Commands	Description
Display interfaces with IPv6 addresses.	show ipv6 interfaces	-

Typical Configuration Example

Configure SLAAC

1. Networking Requirements Multiple hosts are connected to Device A. It is expected to configure an IPv6 address on the interface of Device A, and notify to the hosts to obtain the IPv6 address in a stateful manner as well as other related configuration information.
2. Topology

3. Procedure

#Create a VLAN, configure an IPv6 address, and add VLAN member.

sonic# configure terminal
sonic(config)# vlan 10
sonic(config-vlan-10)# exit
sonic(config)# interface vlan 10
sonic(config-vlanif-10)# ip address 2001::1/64
sonic(config)# interface ethernet 0/0
sonic(config-if-0/0)# switchport access vlan 10

#Enable RA advertisement, advertise IPv6 address prefixes, and set the M and O flag to 1.

sonic(config)# radv enable
Please enter 'radv commit' to take effect
sonic(config)# radv commit
sonic(config)# interface vlan 10
sonic(config-vlanif-10)# radv prefix 2001::/64
Please enter 'radv commit' to take effect
sonic(config-vlanif-10)# radv managed-flag
Please enter 'radv commit' to take effect
sonic(config-vlanif-10)# radv other-config-flag
Please enter 'radv commit' to take effect
sonic(config-vlanif-10)# radv commit

4. Verification

#Display RADV configuration on Device A.

sonic# show radv
Enabled: true
Global unicast only: false
+-------------+-----------+----------------+--------------------+-----------+-----------------+------------+---------+----------------------+---------------------+---------------------+
| Interface   | Prefix    | Managed_Flag   | Otherconfig_Flag   | OffLink   | No-autonomous   | Link_MTU   | RDNSS   | Route | Preference   | MaxRtrAdvInterval   | MinRtrAdvInterval   |
+=============+===========+================+====================+===========+=================+============+=========+======================+=====================+=====================+
| vlan10      | 2001::/64 | on             | on                 |           |                 |            |         |                      |                     |                     |
+-------------+-----------+----------------+--------------------+-----------+-----------------+------------+---------+----------------------+---------------------+---------------------+

#The hosts can ping the gateway.

#Check ND neighbors on Device A.

sonic# show ndp 2001::/64
Address                MacAddress         Iface        Vlan  Status
---------------------  -----------------  ---------  ------  ---------
2001::210:94ff:fe00:1  00:10:94:00:00:01  0/4            10  REACHABLE
2001::210:94ff:fe00:2  00:10:94:00:00:02  0/4            10  REACHABLE
2001::210:94ff:fe00:3  00:10:94:00:00:03  0/4            10  REACHABLE
2001::210:94ff:fe00:4  00:10:94:00:00:04  0/4            10  REACHABLE
2001::210:94ff:fe00:5  00:10:94:00:00:05  0/4            10  REACHABLE
2001::210:94ff:fe00:6  00:10:94:00:00:06  0/4            10  REACHABLE
2001::210:94ff:fe00:7  00:10:94:00:00:07  0/4            10  REACHABLE
2001::210:94ff:fe00:8  00:10:94:00:00:08  0/4            10  REACHABLE
2001::210:94ff:fe00:9  00:10:94:00:00:09  0/4            10  REACHABLE
2001::210:94ff:fe00:a  00:10:94:00:00:0a  0/4            10  REACHABLE
Total number of entries 10