Example for Configuring DHCPv6 Relay Dual-Device Hot Standby

This section describes how to configure DHCPv6 relay dual-device hot standby for a VRRP6 group. After this function is configured and a master/backup VRRP6 switchover is performed, the new master device can properly process services without re-synchronizing user entries.

Networking Requirements

On the network shown in Figure 1, a VRRP6 group is configured on DeviceA and DeviceB to establish a master/backup relationship. DeviceA and DeviceB are the master and backup, respectively. Both DeviceA and DeviceB are DHCPv6 relay agents that forward DHCPv6 client and server packets.

In normal situations, DeviceA forwards user packets, and DeviceB receives user entries synchronized from DeviceA and generates PD routes based on the user entries. If DeviceA or the link between DeviceA and the switch fails, a master/backup VRRP6 switchover is performed, and DeviceB becomes the master. In this case, user packets are switched to DeviceB for forwarding. Users are unaware of the fault.

Figure 1 Networking for configuring DHCPv6 relay dual-device hot standby

Interfaces 1 through 3 in this example represent GE0/1/3, GE0/1/1, and GE0/1/2, respectively.

**Table 1** Interface IP addresses
Device	Interface	Address
DeviceA	GE0/1/3	2001:db8:1::3/64
	GE0/1/1	2001:db8:3::2/64
	GE0/1/2	2001:db8:2::3/64
DeviceB	GE0/1/3	2001:db8:1::2/64
	GE0/1/1	2001:db8:3::1/64
	GE0/1/2	2001:db8:2::2/64

Configuration Roadmap

The configuration roadmap is as follows:

Configure DHCPv6 relay.
Establish a dual-device backup platform.
Enable DHCPv6 relay remote backup.
Bind an RBP to an interface.
Set a cost value for PD routes generated by the backup device in the DHCPv6 relay dual-device hot standby scenario.
Configure daily periodic backup for DHCPv6 relay dual-device hot standby in the RBS view.

Data Preparation

To complete the configuration, you need the following data:

ID of a VRRP6 group configured DeviceA and DeviceB: 1; virtual IPv6 address of the VRRP6 group: 2001:db8:1::1
Priority of DeviceA in the VRRP6 group: 200; preemption delay: 1800s
RBS name: service1; RBP name: profile1; backup ID: 10
Cost value for PD routes generated by the backup device in the DHCPv6 relay dual-device hot standby scenario: 100

Procedure

Configure DHCPv6 relay.

# Configure DeviceA.

<HUAWEI> system-view
[~HUAWEI] sysname DeviceA
[*HUAWEI] commit
[~DeviceA] dhcpv6 export pd-route
[*DeviceA] interface gigabitethernet 0/1/2
[*DeviceA-GigabitEthernet0/1/2] ipv6 enable
[*DeviceA-GigabitEthernet0/1/2] ipv6 nd dad attempts 0
[*DeviceA-GigabitEthernet0/1/2] ipv6 address 2001:db8:2::3/64
[*DeviceA-GigabitEthernet0/1/2] quit
[*DeviceA] commit
[~DeviceA] interface gigabitethernet 0/1/3
[~DeviceA-GigabitEthernet0/1/3] dhcpv6 relay destination 2001:db8:2::1
[*DeviceA-GigabitEthernet0/1/3] dhcpv6 relay source-ip-address 2001:db8:2::3
[*DeviceA-GigabitEthernet0/1/3] quit
[*DeviceA] commit

# Configure DeviceB.

<HUAWEI> system-view
[~HUAWEI] sysname DeviceB
[*HUAWEI] commit
[~DeviceB] dhcpv6 export pd-route
[*DeviceB] interface gigabitethernet 0/1/2
[*DeviceB-GigabitEthernet0/1/2] ipv6 enable
[*DeviceB-GigabitEthernet0/1/2] ipv6 nd dad attempts 0
[*DeviceB-GigabitEthernet0/1/2] ipv6 address 2001:db8:2::2/64
[*DeviceB-GigabitEthernet0/1/2] quit
[*DeviceB] commit
[~DeviceB] interface gigabitethernet 0/1/3
[~DeviceB-GigabitEthernet0/1/3] dhcpv6 relay destination 2001:db8:2::1
[*DeviceB-GigabitEthernet0/1/3] dhcpv6 relay source-ip-address 2001:db8:2::2
[*DeviceB-GigabitEthernet0/1/3] quit
[*DeviceB] commit

Establish a dual-device backup platform.

Configure basic VRRP6 group functions.

# Configure DeviceA.

[~DeviceA] interface gigabitethernet 0/1/3
[~DeviceA-GigabitEthernet0/1/3] ipv6 enable
[*DeviceA-GigabitEthernet0/1/3] ipv6 nd dad attempts 0
[*DeviceA-GigabitEthernet0/1/3] ipv6 address 2001:db8:1::3/64
[*DeviceA-GigabitEthernet0/1/3] vrrp6 vrid 1 virtual-ip FE80::7 link-local
[*DeviceA-GigabitEthernet0/1/3] vrrp6 vrid 1 virtual-ip 2001:db8:1::1
[*DeviceA-GigabitEthernet0/1/3] vrrp6 vrid 1 priority 200
[*DeviceA-GigabitEthernet0/1/3] vrrp6 vrid 1 preempt-mode timer delay 1800
[*DeviceA-GigabitEthernet0/1/3] vrrp6 recover-delay 20
[*DeviceA-GigabitEthernet0/1/3] quit
[*DeviceA] commit

# Configure DeviceB.

[~DeviceB] interface gigabitethernet 0/1/3
[~DeviceB-GigabitEthernet0/1/3] ipv6 enable
[*DeviceB-GigabitEthernet0/1/3] ipv6 nd dad attempts 0
[*DeviceB-GigabitEthernet0/1/3] ipv6 address 2001:db8:1::2/64
[*DeviceB-GigabitEthernet0/1/3] vrrp6 vrid 1 virtual-ip FE80::7 link-local
[*DeviceB-GigabitEthernet0/1/3] vrrp6 vrid 1 virtual-ip 2001:db8:1::1
[*DeviceB-GigabitEthernet0/1/3] quit
[*DeviceB] commit

Configure an RBS.

# Configure DeviceA.

[~DeviceA] interface gigabite preempt-mode timer delaythernet 0/1/1
[~DeviceA-GigabitEthernet0/1/1] ipv6 enable
[*DeviceA-GigabitEthernet0/1/1] ipv6 nd dad attempts 0
[*DeviceA-GigabitEthernet0/1/1] ipv6 address 2001:db8:3::2/64
[*DeviceA-GigabitEthernet0/1/1] commit
[~DeviceA-GigabitEthernet0/1/1] quit
[~DeviceA] remote-backup-service service1
[*DeviceA-rm-backup-srv-service1] peer-ipv6 2001:db8:3::1 source-ipv6 2001:db8:3::2 port 2046
[*DeviceA-rm-backup-srv-service1] quit
[*DeviceA] commit

# Configure DeviceB.

[~DeviceB] interface gigabitethernet 0/1/1
[~DeviceB-GigabitEthernet0/1/1] ipv6 enable
[*DeviceB-GigabitEthernet0/1/1] ipv6 nd dad attempts 0
[*DeviceB-GigabitEthernet0/1/1] ipv6 address 2001:db8:3::1/64
[*DeviceB-GigabitEthernet0/1/1] commit
[~DeviceB-GigabitEthernet0/1/1] quit
[~DeviceB] remote-backup-service service1
[*DeviceB-rm-backup-srv-service1] peer-ipv6 2001:db8:3::2 source-ipv6 2001:db8:3::1 port 2046
[*DeviceB-rm-backup-srv-service1] quit
[*DeviceB] commit

Configure an RBP.

# Configure DeviceA.

[~DeviceA] remote-backup-profile profile1
[*DeviceA-rm-backup-prf-profile1] peer-backup hot
[*DeviceA-rm-backup-prf-profile1] vrrp6-id 1 interface gigabitethernet 0/1/3
[*DeviceA-rm-backup-prf-profile1] backup-id 10 remote-backup-service service1
[*DeviceA-rm-backup-prf-profile1] quit
[*DeviceA] commit

# Configure DeviceB.

[~DeviceB] remote-backup-profile profile1
[*DeviceB-rm-backup-prf-profile1] peer-backup hot
[*DeviceB-rm-backup-prf-profile1] vrrp6-id 1 interface gigabitethernet 0/1/3
[*DeviceB-rm-backup-prf-profile1] backup-id 10 remote-backup-service service1
[*DeviceB-rm-backup-prf-profile1] quit
[*DeviceB] commit

Enable DHCPv6 relay remote backup.

# Enable DHCPv6 relay remote backup in the RBP view of DeviceA.

[~DeviceA] remote-backup-profile profile1
[~DeviceA-rm-backup-prf-profile1] service-type dhcpv6-relay
[*DeviceA-rm-backup-prf-profile1] quit
[*DeviceA] commit

# Enable DHCPv6 relay remote backup in the RBP view of DeviceB.

[~DeviceB] remote-backup-profile profile1
[~DeviceB-rm-backup-prf-profile1] service-type dhcpv6-relay
[*DeviceB-rm-backup-prf-profile1] quit
[*DeviceB] commit

Bind the RBP to an interface.

# Bind the RBP to the DHCPv6 relay interface on DeviceA.

[~DeviceA] interface gigabitethernet 0/1/3
[~DeviceA-GigabitEthernet0/1/3] remote-backup-profile profile1
[*DeviceA-rm-backup-prf-profile1] quit
[*DeviceA] commit

# Bind the RBP to the DHCPv6 relay interface on DeviceB.

[~DeviceB] interface gigabitethernet 0/1/3
[~DeviceB-GigabitEthernet0/1/3] remote-backup-profile profile1
[*DeviceB-rm-backup-prf-profile1] quit
[*DeviceB] commit

Set a cost value for PD routes generated by the backup device in the DHCPv6 relay dual-device hot standby scenario.

# Configure DeviceA.

[~DeviceA] interface gigabitethernet 0/1/3
[~DeviceA-GigabitEthernet0/1/3] dhcpv6 relay pd-route degrade-cost 100
[*DeviceA-GigabitEthernet0/1/3] quit
[*DeviceA] commit

# Configure DeviceB.

[~DeviceB] interface gigabitethernet 0/1/3
[~DeviceB-GigabitEthernet0/1/3] dhcpv6 relay pd-route degrade-cost 100
[*DeviceB-GigabitEthernet0/1/3] quit
[*DeviceB] commit

Configure daily periodic backup for DHCPv6 relay dual-device hot standby in the RBS view.

# Configure DeviceA.

[~DeviceA] remote-backup-service service1
[~DeviceA-rm-backup-srv-service1] batch-backup service-type dhcpv6-relay daily 03:00:00
[*DeviceA-rm-backup-srv-service1] quit
[*DeviceA] commit

# Configure DeviceB.

[~DeviceB] remote-backup-service service1
[~DeviceB-rm-backup-srv-service1] batch-backup service-type dhcpv6-relay daily 03:00:00
[*DeviceB-rm-backup-srv-service1] quit
[*DeviceB] commit

Verify the configuration.

After completing the configuration, run the display remote-backup-profile command on DeviceA. The command output shows that the RBP profile1 has been created.

<DeviceA> display remote-backup-profile profile1
-----------------------------------------------  
 Profile-Index        : 0x1003  
 Profile-Name         : profile1 
 Service              : dhcpv6-relay   
 Remote-backup-service: service1  
 Backup-ID            : 10  
 track protocol       : VRRP6  
 VRRP-ID              : 1  
 VRRP-Interface       : gigabitethernet0/1/3  
 Access-Control       : --  
 State                : Master  
 Peer State           : --  
 Interface            :  
                         gigabitethernet0/1/3  
 Backup mode          : hot  
 Slot-Number          : 1  
 Card-Number          : 0  
 Port-Number          : 0

Run the display remote-backup-profile command on DeviceB. The command output shows that the RBP profile1 has been created.

<DeviceB> display remote-backup-profile profile1
-----------------------------------------------  
 Profile-Index        : 0x1002  
 Profile-Name         : profile1 
 Service              : dhcpv6-relay   
 Remote-backup-service: service1  
 Backup-ID            : 10  
 track protocol       : VRRP6  
 VRRP-ID              : 1  
 VRRP-Interface       : gigabitethernet0/1/3 
 Access-Control       : --  
 State                : Slave  
 Peer State           : --  
 Interface            :  
                        gigabitethernet0/1/3 
 Backup mode          : hot  
 Slot-Number          : 1  
 Card-Number          : 0  
 Port-Number          : 0

Run the display remote-backup-service command on DeviceA. The command output shows that the RBS service1 has been created.

<DeviceA> display remote-backup-service service1
----------------------------------------------------------
 Service-Index    : 3
 Service-Name     : service1
 TCP-State        : Connected
 Peer-ip          : 2001:DB8:3::1
 Source-ip        : 2001:DB8:3::2
 TCP-Port         : 2046
 Track-BFD        : --
 SSL-Policy-Name  : --
 SSL-State        : --
 Last up time     : 2019-01-01 00:00:00
 Batch-backup     : 03:00:00(Daily) for service dhcpv6-relay
----------------------------------------------------------

Run the display remote-backup-service command on DeviceB. The command output shows that the RBS service1 has been created.

<DeviceB> display remote-backup-service service1
----------------------------------------------------------  
 Service-Index    : 2  
 Service-Name     : service1  
 TCP-State        : Connected  
 Peer-ip          : 2001:DB8:3::2  
 Source-ip        : 2001:DB8:3::1  
 TCP-Port         : 2046
 Track-BFD        : --
 SSL-Policy-Name  : --
 SSL-State        : --
 Last up time     : 2019-01-01 00:00:00
 Batch-backup     : 03:00:00(Daily) for service dhcpv6-relay
----------------------------------------------------------

Configuration Files

DeviceA configuration file

# 
sysname DeviceA 
#
dhcpv6 export pd-route
#
remote-backup-service service1
 peer-ipv6 2001:DB8:3::1 source-ipv6 2001:DB8:3::2 port 2046
 batch-backup service-type dhcpv6-relay daily 03:00:00
#
remote-backup-profile profile1
 service-type dhcpv6-relay 
 backup-id 10 remote-backup-service service1
 peer-backup hot
 vrrp6-id 1 interface GigabitEthernet0/1/3
#
interface GigabitEthernet0/1/3
 ipv6 enable
 ipv6 address 2001:DB8:1::3/64
 vrrp6 vrid 1 virtual-ip FE80::7 link-local
 vrrp6 vrid 1 virtual-ip 2001:DB8:1::1
 vrrp6 vrid 1 priority 200
 vrrp6 vrid 1 preempt-mode timer delay 1800
 vrrp6 recover-delay 20
 ipv6 nd dad attempts 0
 remote-backup-profile profile1
 dhcpv6 relay destination 2001:DB8:2::1
 dhcpv6 relay source-ip-address 2001:DB8:2::3
 dhcpv6 relay pd-route degrade-cost 100
# 
interface GigabitEthernet0/1/1
 ipv6 enable
 ipv6 address 2001:DB8:3::2/64
 ipv6 nd dad attempts 0
#
interface GigabitEthernet0/1/2
 ipv6 enable    
 ipv6 address 2001:DB8:2::3/64
 ipv6 nd dad attempts 0
#
return

DeviceB configuration file

# 
sysname DeviceB
#
dhcpv6 export pd-route
#
remote-backup-service service1
 peer-ipv6 2001:DB8:3::2 source-ipv6 2001:DB8:3::1 port 2046
 batch-backup service-type dhcpv6-relay daily 03:00:00
#
remote-backup-profile profile1
 service-type dhcpv6-relay 
 backup-id 10 remote-backup-service service1
 peer-backup hot
 vrrp6-id 1 interface GigabitEthernet0/1/3 
#
interface GigabitEthernet0/1/3
 ipv6 enable
 ipv6 address 2001:DB8:1::2/64
 vrrp6 vrid 1 virtual-ip FE80::7 link-local 
 vrrp6 vrid 1 virtual-ip 2001:DB8:1::1
 ipv6 nd dad attempts 0
 remote-backup-profile profile1
 dhcpv6 relay destination 2001:DB8:2::1
 dhcpv6 relay source-ip-address 2001:DB8:2::2
 dhcpv6 relay pd-route degrade-cost 100
#
interface GigabitEthernet0/1/1
 ipv6 enable
 ipv6 address 2001:DB8:3::1/64
 ipv6 nd dad attempts 0
#
interface GigabitEthernet0/1/2
 ipv6 enable
 ipv6 address 2001:DB8:2::2/64
 ipv6 nd dad attempts 0
#
return