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Amyoussef's avatar
Amyoussef
Icon for Nimbostratus rankNimbostratus
Nov 03, 2022
Solved

F5 ltm load balancer

Hello, 

We have a routers load balancing problem.

We have one pool that contain two routers isp1 and isp2 with round robin and icmp health monitor.

One virtual server that handle traffic from lan to wan, without persistence.

Problem:

I start downloading iso from internet ( linux iso for example) and i start ping 8.8.8.8, when i turned off one router ( isp1 or isp2 ) the iso download stop and the ping stop however at the same time if i try to ping anouther address it work and if i try to download anouther iso from another server it work.

 

application delivery
  • Mohamed_Ahmed_Kansoh's avatar
    Mohamed_Ahmed_Kansoh
    Nov 04, 2022

    Hi Amyoussef , 
              I see that this issue is arising out of breaking a stateful connection when turning off one of your pool members which means one of your router.
    I do not know what type of virtual servers do you use in this implementation , but I would like to share with you a solution from my perspective. 

    > First , go to ( Local traffic > Pool > choose your pool > select properties > Select advanced in configuration field > then Action On Service Down and choose "reselect" Option ). 

    > By enabling " Action On Service Down" feature you make a quite stateful connections and maintains it when one of your routers become unavailable. 
    Please note , you need to adjust your virtual server such as ( not using tcp profile and disable Port and address translation ) , also if the traffic goes through a firewall to internet you need make sure that traffic will be allowed through this firewall if one of routers become unavailable. 

    > Please refer to this KB as well , it will help you to configure "Action On Service Down" feature well : 


        https://support.f5.com/csp/article/K15095

    I hope you get ride of your issue soon. 
    Goodluck 

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  • LiefZimmerman's avatar
    LiefZimmerman
    Icon for Admin rankAdmin
    Jan 12, 2023

    Amyoussef - I've marked Mohamed_Ahmed_Kansoh's answer as the solution. If you disagree, or want to add Paulius as another part of the Solution feel free to select/unselect Accept As Solution on the relevant posts.

    This helps future readers find answers more quickly and confirms the efforts of those who helped.
    Thanks for being part of our community.
    Lief

  • Mohamed_Ahmed_Kansoh's avatar
    Mohamed_Ahmed_Kansoh
    Icon for MVP rankMVP
    Nov 04, 2022

    Hi Amyoussef , 
              I see that this issue is arising out of breaking a stateful connection when turning off one of your pool members which means one of your router.
    I do not know what type of virtual servers do you use in this implementation , but I would like to share with you a solution from my perspective. 

    > First , go to ( Local traffic > Pool > choose your pool > select properties > Select advanced in configuration field > then Action On Service Down and choose "reselect" Option ). 

    > By enabling " Action On Service Down" feature you make a quite stateful connections and maintains it when one of your routers become unavailable. 
    Please note , you need to adjust your virtual server such as ( not using tcp profile and disable Port and address translation ) , also if the traffic goes through a firewall to internet you need make sure that traffic will be allowed through this firewall if one of routers become unavailable. 

    > Please refer to this KB as well , it will help you to configure "Action On Service Down" feature well : 


        https://support.f5.com/csp/article/K15095

    I hope you get ride of your issue soon. 
    Goodluck 

  • Paulius's avatar
    Paulius
    Icon for MVP rankMVP
    Nov 06, 2022

    AmyoussefIn this topology does your BIG-IP have to act as your gateway to your ISP routers? If not you would probably benefit more from having your own edge router or firewall and configuring ECMP on it and point to ISP1 and ISP2 routers. You can then move your F5 further down from the edge and have it handle load balancing for websites, applications, and various other tasks that it is more suited to handling. If you must use the BIG-IP as your edge then Mohamed's response could fix your issue.