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Cristiano_Costa's avatar
Cristiano_Costa
Icon for Nimbostratus rankNimbostratus
May 17, 2018

DOS Layer 7 memory consumption

Hello,

 

Recently we had a problem where BIGIP started killing several tcp connections. Analyzing the issue we discovered that the TMM "used memory" was over 85% and BIGIP began to kill the connections.

 

So, we started looking why TMM was using so much memory and found out that the "Memory Pool" with the name "DoS Layer 7 ACY" was using 2.7G (a much higher value than any other entry in the memory pool table).

 

Does this "DoS Layer 7 ACY" use TMM's allocated memory? If yes, is there a way to reduce this amount of memory?

 

ps:

 

  • BIGIP VE 12.1.1 (LTM, ASM, AVR, AFM and AAM);
  • We use "DOS Layer 7" feature in 15 Virtual Servers (mainly to block bots);
  • We have 5.6G allocated to TMM.

Thank you,

 

Cristiano

 

ASM Advanced WAF
BIG-IP
connection reset
dos layer 7
high memory utilization
security
tmm memory
  • Cristiano_Costa's avatar
    Cristiano_Costa
    Icon for Nimbostratus rankNimbostratus
    Jul 12, 2018

    Yes, I did.

     

    The solution was to increase the amount of memory in my virtual machine to stop the connection killing. It seems that the DoS feature is consuming a lot of memory in my setup.

     

  • boneyard's avatar
    boneyard
    Icon for MVP rankMVP
    May 20, 2018

    i would advise you to open a ticket with F5 support, they can look at your full setup and provide better guidance on memory changes.