Basic Layer 4 server load balancing configuration example

In Figure 48, physical servers Server A, Server B, and Server C provide FTP services, and are in descending order of hardware configuration.

Configure server load balancing on the LB device to distribute user requests among the servers based on their hardware performance, and use health monitoring to monitor the reachability of the servers.

1. Configure the LB device:

   • Configure IP addresses for interfaces.

     <LB> system-view
     [LB] interface gigabitethernet 1/0/1
     [LB-GigabitEthernet1/0/1] ip address 61.159.4.100 24
     [LB-GigabitEthernet1/0/1] quit
     [LB] interface gigabitethernet 1/0/2
     [LB-GigabitEthernet1/0/2] ip address 192.168.1.100 24
     [LB-GigabitEthernet1/0/2] quit
     

   • Configure a server farm.

     # Create the ICMP-type NQA template t1.

     [LB] nqa template icmp t1
     [LB-nqatplt-icmp-t1] quit
     

     # Create the server farm sf, and specify the scheduling algorithm as weighted round robin and health monitoring method as t1.

     [LB] server-farm sf
     [LB-sfarm-sf] predictor round-robin
     [LB-sfarm-sf] probe t1
     [LB-sfarm-sf] quit
     

   • Configure real servers.

     # Create the real server rs1 with IPv4 address 192.168.1.1, port number 21, and weight 150, and add it to the server farm sf.

     [LB] real-server rs1
     [LB-rserver-rs1] ip address 192.168.1.1
     [LB-rserver-rs1] port 21
     [LB-rserver-rs1] weight 150
     [LB-rserver-rs1] server-farm sf
     [LB-rserver-rs1] quit
     

     # Create the real server rs2 with IPv4 address 192.168.1.2, port number 21, and weight 120, and add it to the server farm sf.

     [LB] real-server rs2
     [LB-rserver-rs2] ip address 192.168.1.2
     [LB-rserver-rs2] port 21
     [LB-rserver-rs2] weight 120
     [LB-rserver-rs2] server-farm sf
     [LB-rserver-rs2] quit
     

     # Create the real server rs3 with IPv4 address 192.168.1.3, port number 21, and weight 80, and add it to the server farm sf.

     [LB] real-server rs3
     [LB-rserver-rs3] ip address 192.168.1.3
     [LB-rserver-rs3] port 21
     [LB-rserver-rs3] weight 80
     [LB-rserver-rs3] server-farm sf
     [LB-rserver-rs3] quit
     

   • Configure a virtual server.

     # Create the TCP virtual server vs with VSIP 61.159.4.100, specify its default master server farm sf, and enable the virtual server.

     [LB] virtual-server vs type tcp
     [LB-vs-tcp-vs] virtual ip address 61.159.4.100
     [LB-vs-tcp-vs] default server-farm sf
     [LB-vs-tcp-vs] service enable
     [LB-vs-tcp-vs] quit
     

2. Configure the physical servers:

   # Specify the default gateway 192.168.1.100 for physical servers Server A, Server B, and Server C. (Details not shown.)

# Display brief information about all real servers.

[LB] display real-server brief
Real server      Address              Port  State       VPN instance   Server farm
rs1              192.168.1.1          21    Active                     sf
rs2              192.168.1.2          21    Active                     sf
rs3              192.168.1.3          21    Active                     sf

# Display detailed information about all server farms.

[LB] display server-farm
Server farm: sf
  Description:
  Predictor: Round robin
  Proximity: Disabled
  NAT: Enabled
  SNAT pool:
  Failed action: Keep
  Active threshold: Disabled
  Slow-online: Disabled
  Selected server: Disabled
  Probe information:                                                            
    Probe success criteria: All                                                 
    Probe method:                                                               
    t1
  Total real server: 3
  Active real server: 3
  Real server list:
  Name             State    VPN instance      Address           Port  Weight Priority
  rs1              Active                     192.168.1.1       21    150    4
  rs2              Active                     192.168.1.2       21    120    4
  rs3              Active                     192.168.1.3       21    80     4

# Display detailed information about all virtual servers.

[LB] display virtual-server
Virtual server: vs
  Description:
  Type: TCP
  State: Active
  VPN instance:
  Virtual IPv4 address: 61.159.4.100/32
  Virtual IPv6 address: --
  Port: 0
  Primary server farm: sf (in use)
  Backup server farm:
  Sticky:
  LB policy:
  Connection limit: --
  Rate limit:
    Connections: --
    Bandwidth: --
    Inbound bandwidth: --
    Outbound bandwidth: --
  Connection synchronization: Disabled
  Sticky synchronization: Disabled
  Bandwidth busy protection: Disabled
  Interface bandwidth statistics: Disabled
  Route advertisement: Disabled