Forum Discussion

neeeewbie's avatar
Nov 08, 2024

Change LB priority based on status

Hi I need help!

Load balance traffic between server A (IP: 1.1.1.1) and server B (IP: 1.1.1.2).
When server A goes down, traffic should be sent to server B.
Even when server A comes back up, traffic should be sent only to server B until server B goes down, and no traffic should be sent to server A.

The same thing happens in reverse.

When server B goes down, traffic should be sent to server A.
Even when server B comes back up, traffic should be sent only to server A until server A goes down, and no traffic should be sent to server B.

Is this setup possible in F5?

 

thank you

  • Hi ,

     

    I only tried this backup method with priority group activation, but it will not work like this

    FOR Eg :) if server A have high priority

    • When both servers are available:
      • Traffic is directed to the server with the highest priority (e.g., Server A).
      • Server B (lower priority) remains on standby and does not receive traffic unless Server A fails.
    • If Server A goes offline:
      • Server B (backup) starts receiving traffic because it becomes the highest available priority member.
    • If Server A comes back online:
      • Traffic automatically returns to Server A due to its higher priority.

    This is an option for backup server(if you need both servers accept connection, this is not expected solution)

     

    Also could u please check manual resume is fine for u, its more near for your request. - Overview of the Manual Resume feature for BIG-IP LTM monitors

    Try this as well in your servers 

     

    BR

    Aswin

     

     

  • Hiii neeeewbie

     

    can you paste the configuration of the pool here?
    In theory, the server A needles high priority for always be a first server in response first

     

     

  • neeeewbie I don't believe this is possible with just the LTM. I believe what you would really want is a GTM to server 2 virtual servers, one with server A in the pool and one with server B in the pool. Once you have that configuration in place you would set the GTM to balance DNS queries between the two sites and only give one site or the other if the opposing site virtual server failed. Maybe it's possible with TCL in an iRule but I don't believe anything exists that would have a running tally like you would need in order to flip back and forth between pool members.