Example for Performing Capacity Expansion in a Dual-Device Hot Backup Scenario

This section describes how to expand the interface capacity and change a user access interface in a dual-device hot backup scenario.

Networking Requirements

In a dual-device hot backup scenario, a pair of RBP instances in master/backup mode must be configured on the master and backup devices to back up services between the two devices.

On the example network, users access BRAS 1 and BRAS 2 through the LAN switch (LSW). The user access interfaces on the two devices are GE or Eth-Trunk interfaces.

The dual-device hot backup mechanism determines the corresponding RBP instance based on the backup ID and RBS values in the backup table, and then determines the user access interface based on the RBP instance and user VLAN ID. The values of the backup ID, RBS, and VLAN ID cannot be changed.

Figure 1 Performing capacity expansion in an IPv6 dual-device hot backup scenario

In this example, interface 1 and interface 2 represent GE 0/1/0 and GE 0/1/16, respectively.



Device Name

Interface Name

IP Address and Mask

BRAS1

GE 0/1/0.1

This is a BAS interface, and no IP address needs to be configured.

BRAS1

GE 0/1/16

10.1.1.1/24

BRAS2

GE 0/1/0.1

This is a BAS interface, and no IP address needs to be configured.

BRAS2

GE 0/1/16

10.1.1.2/24

Configuration Roadmap

You can use either of the following methods for capacity expansion in dual-device hot backup scenarios.

  • Add an Eth-Trunk member interface for capacity expansion.
    1. Expand the capacity of BRAS 1. Shut down the original Eth-Trunk member interface on BRAS 1. Then, a master/backup device switchover is performed. BRAS 1 functions as the backup device, and users on BRAS 1 are switched to BRAS 2.
    2. Add a new member interface to the Eth-Trunk interface on BRAS 1.

      Ensure that the new member interface is of the same type as the existing member interface. Otherwise, the new member interface fails to be added. For example, if the existing member interface is a 10GE interface but the new member interface is a 100GE interface, the new member interface fails to be added to the Eth-Trunk interface. You must remove the existing member interface and then add the new member interface.

    3. Enable the existing Eth-Trunk member interface on BRAS 1 to restore user services.
  • Create a BAS interface to replace the original one for capacity expansion.
    1. Expand the capacity of BRAS 1. Disconnect the RBS channel between the master and backup devices, and shut down the user access interface on BRAS 1. Then, a master/backup device switchover is performed. BRAS 1 functions as the backup device, and users on BRAS 1 are switched to BRAS 2.
    2. Log out online users.

      Online users can be logged out only after the RBS channel between the master and backup devices is disconnected. Otherwise, users on the peer device are logged out.

    3. Delete the user access configurations of the original BAS interface on BRAS 1, create a BAS interface on BRAS 1, and synchronize the configurations of the original BAS interface to the new BAS interface.
    4. Restore the RBS channel between the master and backup devices.

The configurations on BRAS 2 are similar to those on BRAS 1. For details about configurations on BRAS 2, see the configuration file of BRAS 2.

The BAS interface can be a GE or an Eth-Trunk interface. When an Eth-Trunk interface is used for capacity expansion, adding an Eth-Trunk member interface is recommended.

Data Preparation

To complete the configuration, you need the following data:

  • VRRP parameters (VRRP ID and preemption delay)

  • RBS channel parameters

  • IP address of each interface on BRAS 1 and BRAS 2

  • Backup ID, which works together with an RBS to identify an RBP to which users belong

Procedure

  • Add an Eth-Trunk member interface for capacity expansion.
    1. Expand the capacity of BRAS 1. Shut down the existing Eth-Trunk member interface on BRAS 1. Then, users on BRAS 1 are switched to BRAS 2, and BRAS 1 functions as the backup device.

      # In this example, the interface GigabitEthernet 0/1/0 command has been configured before capacity expansion is performed.

      [~BRAS1] interface GigabitEthernet 0/1/0               
[*BRAS1-GigabitEthernet0/1/0] shutdown                           
[*BRAS1-GigabitEthernet0/1/0] commit            
[~BRAS1-GigabitEthernet0/1/0] quit

    2. Add a new member interface to the Eth-Trunk interface on BRAS 1.

      # In this example, interface GigabitEthernet 0/1/1 is used as the new Eth-Trunk member interface.

      [~BRAS1] interface GigabitEthernet 0/1/1               
[*BRAS1-GigabitEthernet0/1/1] eth-trunk 1                           
[*BRAS1-GigabitEthernet0/1/1] commit            
[~BRAS1-GigabitEthernet0/1/1] quit

    3. Enable the existing Eth-Trunk member interface on BRAS 1 to restore user services.

      [~BRAS1] interface GigabitEthernet 0/1/0               
[*BRAS1-GigabitEthernet0/1/0] undo shutdown                           
[*BRAS1-GigabitEthernet0/1/0] commit            
[~BRAS1-GigabitEthernet0/1/0] quit

    4. Verify the configuration of capacity expansion in the dual-device hot backup scenario.

      [BRAS1] display interface eth-trunk 1
 -----------------------------------------------
  Eth-Trunk1 current state : UP (ifindex: 33)
  Line protocol current state : DOWN 
  Link quality grade : GOOD
  Description: 
  Route Port,Hash arithmetic : According to flow, Maximal BW: 100Mbps, Current BW: 100Mbps, The Maximum Transmit Unit is 1500
  Internet protocol processing : disabled
  IP Sending Frames' Format is PKTFMT_ETHNT_2, Hardware address is 00e0-fc12-3456
  Current system time: 2019-01-03 03:13:49
  Physical is ETH_TRUNK
     Last 300 seconds input rate 0 bits/sec, 0 packets/sec
     Last 300 seconds output rate 1054 bits/sec, 0 packets/sec
     Input: 0 packets,0 bytes
            0 unicast,0 broadcast,0 multicast
            0 errors,0 drops
     Output:5 packets,0 bytes
            0 unicast,3 broadcast,2 multicast
            0 errors,0 drops
     Last 300 seconds input utility rate:  0.00%
     Last 300 seconds output utility rate: 0.01%
  ----------------------------------------------------------
  PortName                      Status              Weight   
  ----------------------------------------------------------
  GigabitEthernet0/1/0          UP                  1        
  GigabitEthernet0/1/1          UP                  1        
 ----------------------------------------------------------
  The Number of Ports in Trunk : 1
  The Number of UP Ports in Trunk : 1

  • Create a BAS interface to replace the original one for capacity expansion.
    1. Expand the capacity of BRAS 1. Disconnect the RBS channel between the master and backup devices, and shut down the user access interface on BRAS 1. Then, users on BRAS 1 are switched to BRAS 2, and BRAS 1 functions as the backup device.

      [~BRAS1] interface GigabitEthernet 0/1/0               
[*BRAS1-GigabitEthernet0/1/0] shutdown                           
[*BRAS1-GigabitEthernet0/1/0] commit            
[~BRAS1-GigabitEthernet0/1/0] quit

    2. Log out online users.

      [~BRAS1] remote-backup-service s1               
[*BRAS1-rm-backup-srv-s1] shutdown                           
Warning: This operation will cause the TCP connection to be interrupted. Continue? [Y/N]:Y
[*BRAS1-rm-backup-srv-s1] commit            
[~BRAS1-rm-backup-srv-s1] quit                             
[~BRAS1] aaa
[*BRAS1-aaa] cut access-user interface GigabitEthernet 0/1/0

    3. Delete the user access configurations of the original BAS interface on BRAS 1, create a BAS interface on BRAS 1, and synchronize the configurations of the original BAS interface to the new BAS interface.

      [~BRAS1] interface GigabitEthernet 0/1/0.1               
[*BRAS1-GigabitEthernet0/1/0.1] shutdown                           
[*BRAS1-GigabitEthernet0/1/0.1] commit
[~BRAS1-GigabitEthernet0/1/0.1] undo user-vlan 2
[~BRAS1-GigabitEthernet0/1/0.1] undo remote-backup-profile p1
[~BRAS1-GigabitEthernet0/1/0.1] commit
[*BRAS1-GigabitEthernet0/1/0.1] quit
[~BRAS1] interface GigabitEthernet 0/1/1.1
[~BRAS1-GigabitEthernet0/1/1.1] ipv6 enable
[*BRAS1-GigabitEthernet0/1/1.1] ipv6 address auto link-local
[*BRAS1-GigabitEthernet0/1/1.1] ipv6 nd autoconfig managed-address-flag
[*BRAS1-GigabitEthernet0/1/1.1] ipv6 nd autoconfig other-flag
[*BRAS1-GigabitEthernet0/1/1.1] user-vlan 2
[*BRAS1-GigabitEthernet0/1/1.1] remote-backup-profile p1
[*BRAS1-GigabitEthernet0/1/1.1] bas
[*BRAS1-GigabitEthernet0/1/1.1-bas] access-type layer2-subscriber default-domain authentication huawei
[*BRAS1-GigabitEthernet0/1/1.1-bas] authentication-method-ipv6 bind
[*BRAS1-GigabitEthernet0/1/1.1-bas] commit
[~BRAS1-GigabitEthernet0/1/1.1-bas] quit
[~BRAS1-GigabitEthernet0/1/1.1] quit

    4. Restore the RBS channel between the master and backup devices.

      [~BRAS1] remote-backup-service s1               
[*BRAS1-rm-backup-srv-s1] undo shutdown                           
[*BRAS1-rm-backup-srv-s1] commit            
[~BRAS1-rm-backup-srv-s1] quit

Configuration Files

  • Add an Eth-Trunk member interface for capacity expansion.

    • BRAS 1 configuration file

      #
 sysname BRAS1
 #
 ipv6
 #
 bfd
 #
 mpls
 #
 mpls ldp
 #
 ipv6 prefix prefix1 local
  prefix 2001:db8:1::2013/64
 #
 ipv6 pool pool1 bas local
  prefix prefix1
 #
 aaa
  domain huawei   
   authentication-scheme default0                    
   accounting-scheme default0                  
   ipv6-pool pool1
 #
 remote-backup-service s1                      
  peer 10.1.2.2 source 10.1.2.1 port 6001       
  protect lsp-tunnel for-all-instance peer-ip 10.1.2.2   
  track interface GigabitEthernet0/1/9          
  ipv6-pool pool1
 #
 remote-backup-profile p1                       
  service-type bras         
  backup-id 1 remote-backup-service s1                   
  peer-backup hot                    
  vrrp-id 1 interface Eth-Trunk1.2
 #
 #
 interface GigabitEthernet 0/1/0
  shutdown
  eth-trunk 1
 #
 interface GigabitEthernet 0/1/1
  undo shutdown
  eth-trunk 1
 #
 #
 interface Eth-Trunk1.2              
  vlan-type dot1q 1                             
  ip address 10.1.1.1 255.255.255.0            
  vrrp vrid 1 virtual-ip 10.1.1.100            
  admin-vrrp vrid 1                             
  vrrp vrid 1 priority 180                      
  vrrp vrid 1 preempt-mode timer delay 60       
  vrrp vrid 1 track interface GigabitEthernet0/1/8 reduced 50                    
  vrrp vrid 1 track bfd-session session-name bfd1 peer
  vrrp recover-delay 20
 #
 interface Eth-Trunk1.1            
  ipv6 enable  
  ipv6 address auto link-local                  
  ipv6 nd autoconfig managed-address-flag       
  ipv6 nd autoconfig other-flag                           
  user-vlan 2   
  remote-backup-profile p1                       
  bas          
   access-type layer2-subscriber default-domain authentication huawei   
   authentication-method-ipv6 bind
 #
 interface LoopBack1
  ip address 10.1.2.1 255.255.255.255
 #
 bfd bfd1 bind peer-ip 10.1.1.2
  discriminator local 8
  discriminator remote 6
 #
 ospf 1        
  import-route direct                           
  area 0.0.0.0 
  network 10.1.2.1 0.0.0.0
 #
 return
 #

    • BRAS 2 configuration file

      #
 sysname BRAS2
 #
 ipv6
 #
 bfd
 #
 mpls
 #
 mpls ldp
 #
 ipv6 prefix prefix1 local
  prefix 2001:db8:1::2013/64
 #
 ipv6 pool pool1 bas local
  prefix prefix1
 #
 aaa
  domain huawei   
   authentication-scheme default0                    
   accounting-scheme default0                  
   ipv6-pool pool1
 #
 remote-backup-service s1
  peer 10.1.2.1 source 10.1.2.2 port 6001
  protect lsp-tunnel for-all-instance peer-ip 10.1.2.1
  track interface GigabitEthernet0/1/9
 #
 remote-backup-profile p1
  service-type bras
  backup-id 1 remote-backup-service s1
  peer-backup hot
  vrrp-id 1 interface Eth-Trunk1.2
 #
 #
 interface GigabitEthernet 0/1/0
  shutdown
  eth-trunk 1
 #
 interface GigabitEthernet 0/1/1
  undo shutdown
  eth-trunk 1
 #
 interface Eth-Trunk1.2              
  vlan-type dot1q 1                             
  ip address 10.1.1.2 255.255.255.0           
  vrrp vrid 1 virtual-ip 10.1.1.100            
  admin-vrrp vrid 1                             
  vrrp vrid 1 priority 150                      
  vrrp vrid 1 track interface GigabitEthernet0/1/8 reduced 50                    
  vrrp vrid 1 track bfd-session session-name bfd1 peer
 #
 interface Eth-Trunk1.1          
  ipv6 enable  
  ipv6 address auto link-local                  
  ipv6 nd autoconfig managed-address-flag       
  ipv6 nd autoconfig other-flag                            
  user-vlan 2   
  remote-backup-profile p1                 
  bas          
   access-type layer2-subscriber default-domain authentication huawei
   authentication-method-ipv6 bind
 #
 interface LoopBack1
  ip address 10.1.2.2 255.255.255.255
 #
 bfd bfd2 bind peer-ip 10.1.2.1                
  discriminator local 6                         
  discriminator remote 8                        
 #
 ospf 1
  import-route direct
  area 0.0.0.0
  network 10.1.2.2 0.0.0.0
 #
 return
 #
  • Create a BAS interface to replace the original one for capacity expansion.

    • BRAS 1 configuration file

      #
 sysname BRAS1
 #
 ipv6
 #
 bfd
 #
 mpls
 #
 mpls ldp
 #
 ipv6 prefix prefix1 local
  prefix 2001:db8:1::2013/64
 #
 ipv6 pool pool1 bas local
  prefix prefix1
 #
 aaa
  domain huawei   
   authentication-scheme default0                    
   accounting-scheme default0                  
   ipv6-pool pool1
 #
 remote-backup-service s1                      
  peer 10.1.2.2 source 10.1.2.1 port 6001       
  protect lsp-tunnel for-all-instance peer-ip 10.1.2.2   
  track interface GigabitEthernet0/1/8          
  ipv6-pool pool1
 #
 remote-backup-profile p1                       
  service-type bras         
  backup-id 1 remote-backup-service s1                   
  peer-backup hot                    
  vrrp-id 1 interface GigabitEthernet0/1/0.2
  nas logic-port GigabitEthernet 0/1/0
  nas logic-sysname huawei
  nas logic-ip 1.1.1.1
 #
 interface GigabitEthernet0/1/0.2              
  vlan-type dot1q 1                             
  ip address 10.1.1.1 255.255.255.0            
  vrrp vrid 1 virtual-ip 10.1.1.100            
  admin-vrrp vrid 1                             
  vrrp vrid 1 priority 180                      
  vrrp vrid 1 preempt-mode timer delay 60       
  vrrp vrid 1 track interface GigabitEthernet0/1/8 reduced 50                    
  vrrp vrid 1 track bfd-session session-name bfd1 peer
  vrrp recover-delay 20
 #
 interface GigabitEthernet0/1/0.1    
  shutdown        
  ipv6 enable 
  ipv6 address auto link-local 
  ipv6 nd autoconfig managed-address-flag 
  ipv6 nd autoconfig other-flag 
  bas
   access-type layer2-subscriber default-domain authentication huawei
   authentication-method-ipv6 bind
 #
 interface GigabitEthernet0/1/1.1            
  ipv6 enable  
  ipv6 address auto link-local                  
  ipv6 nd autoconfig managed-address-flag       
  ipv6 nd autoconfig other-flag                           
  user-vlan 2   
  remote-backup-profile p1                       
  bas          
   access-type layer2-subscriber default-domain authentication huawei   
   authentication-method-ipv6 bind
 #
 interface LoopBack1
  ip address 10.1.2.1 255.255.255.255
 #
 bfd bfd1 bind peer-ip 10.1.1.2
  discriminator local 8
  discriminator remote 6
 #
 ospf 1        
  import-route direct                           
  area 0.0.0.0 
  network 10.1.2.1 0.0.0.0
 #
 return
 #

    • BRAS 2 configuration file

      #
 sysname BRAS2
 #
 ipv6
 #
 bfd
 #
 mpls
 #
 mpls ldp
 #
 ipv6 prefix prefix1 local
  prefix 2001:db8:1::2013/64
 #
 ipv6 pool pool1 bas local
  prefix prefix1
 #
 aaa
  domain huawei   
   authentication-scheme default0                    
   accounting-scheme default0                  
   ipv6-pool pool1
 #
 remote-backup-service s1
  peer 10.1.2.1 source 10.1.2.2 port 6001
  protect lsp-tunnel for-all-instance peer-ip 10.1.2.1
  track interface GigabitEthernet0/1/8
 #
 remote-backup-profile p1
  service-type bras
  backup-id 1 remote-backup-service s1
  peer-backup hot
  vrrp-id 1 interface GigabitEthernet0/1/0.2
  nas logic-port GigabitEthernet 0/1/0
  nas logic-sysname huawei
  nas logic-ip 1.1.1.1
 #
 interface GigabitEthernet0/1/0.2              
  vlan-type dot1q 1                             
  ip address 10.1.1.2 255.255.255.0           
  vrrp vrid 1 virtual-ip 10.1.1.100            
  admin-vrrp vrid 1                             
  vrrp vrid 1 priority 150                      
  vrrp vrid 1 track interface GigabitEthernet0/1/8 reduced 50                    
  vrrp vrid 1 track bfd-session session-name bfd1 peer
 #
 interface GigabitEthernet0/1/0.1        
  shutdown  
  ipv6 enable 
  ipv6 address auto link-local 
  ipv6 nd autoconfig managed-address-flag 
  ipv6 nd autoconfig other-flag 
  bas
   access-type layer2-subscriber default-domain authentication huawei
   authentication-method-ipv6 bind
 #
 interface GigabitEthernet0/1/1.1          
  ipv6 enable  
  ipv6 address auto link-local                  
  ipv6 nd autoconfig managed-address-flag       
  ipv6 nd autoconfig other-flag                            
  user-vlan 2   
  remote-backup-profile p1                 
  bas          
   access-type layer2-subscriber default-domain authentication huawei
   authentication-method-ipv6 bind
 #
 interface LoopBack1
  ip address 10.1.2.2 255.255.255.255
 #
 bfd bfd2 bind peer-ip 10.1.2.1                
  discriminator local 6                         
  discriminator remote 8                        
 #
 ospf 1
  import-route direct
  area 0.0.0.0
  network 10.1.2.2 0.0.0.0
 #
 return
 #
Parent Topic: Configuration Examples
Copyright © Huawei Technologies Co., Ltd.
Copyright © Huawei Technologies Co., Ltd.
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