We can adjust load balancing ratio according to servers consuming resource such as CPU, Memory and Disk.

In this lab i will be apply this scenario :

  • F5 will monitor server resources via SNMP Agent
  • then F5 will assign ratio on the nodes dynamicaly and perform load balancing

Here is the lab topology ;

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On the Window Servers Perfom Following Task

  • Assign IP address, subnet mask and default gw
  • Windows firewall disable
  • Run IIS Servive
  • Run SNMP Service and configure security strings : TEST , allow IP : any

On the F5

  • Create SNMP DCA monitor, to accomplish that Local Traffic » Monitor » Create
    • Name : snmp_dca_monitor
    • Community : TEST
    • Version : v2c
    • Agent Type : WIN2000

other setting will be remain default or whatever you want.

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  • Assign nodes and add monitor them with snmp_dca_agent Local Traffic > Nodes > Create

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all other two nodes added same way

  • Crete Pool with Load Balancing Method Dynamic Ratio (nodes) and assign pool members and monitor pool member with http

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  • Cretae VS Server
    • IP Address : 192.168.138.200
    • Service Port : 80
    • Default Pool : test-web-pool

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  • Verify dynamic ratio rates from F5 cli

tmsh list ltm nodes dynamic-ratio

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At this moment server 1 resources :

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At this moment server 2 resources :

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At this moment server 3 resources :

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  • Enable and view snmp dca agent logs on the F5

from cli

tmsh modify /sys db snmp.snmpdca.log value true

cat /shared/tmp/snmpdca.log

  • Perform Syn flood from layer 2 network with hping3 and check the dynamic ratio rates from cli.

hping3 -c 15000 -d 120 -S -w 64 -p 80 --flood --rand-source 20.20.20.21

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tmsh list ltm node dynamic-ratio

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At this time server 1 resources

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