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Larry_G_54476's avatar
Larry_G_54476
Icon for Nimbostratus rankNimbostratus
Nov 29, 2011

F5 Load Balancer VIP pointing to 2 groups of SMTP servers

I have a F5 Load Balancers.

 

 

I want to create a global vip.

 

 

The vip should load balance traffic to 4 SMTP servers in group A.

 

 

The F5 should chekc the health of the 4 SMTP servers in group A.

 

 

If the health check fails and all 4 SMTP servers in group A are not available, I would like the F5 to direct SMTP traffic through the VIP to 4 OTHER SMTP servers (group B).

 

 

The F5 would continue to direct traffic to group B servers until the group A servers come back up.

 

 

Can the F5 do this?

 

 

Thanks

 

Larry
microsoft
partner

2 Replies

  • Helen_Johnson_1's avatar
    Helen_Johnson_1
    Historic F5 Account
    Dec 15, 2011
    Hi Larry,

     

     

    To answer your question, the F5 can do this.

     

     

    In order to have this work the way you want it to, you'll want to monitor both groups, or pools in F5 lingo. Then you'd need an iRule that sends all traffic to the servers in group A, until all 4 are marked down, then send traffic to group B. The forums for iRules can be found here: http://devcentral.f5.com/Forums/tabid/1082223/asg/50/showtab/groupforums/aff/5/Default.aspx

     

     

    By default, the BIG-IP will continue to monitor all pool members and report when they're back up and ready to accept traffic. As a result, the VIP will send traffic to the servers in group A once it sees them as back online.

     

     

    Please let us know if you have further questions.

     

     

    Cheers,

     

    Helen
  • Helen_Johnson_1's avatar
    Helen_Johnson_1
    Historic F5 Account
    Dec 15, 2011
    Hi Larry,

     

     

    I thought of something else after I hit submit...

     

     

    Instead of using iRules, another way to accomplish your goal would be to do priority group activation. Put the members of both groups A and B into a pool, and assign the members that are in group A a higher priority group than those in group B. For more information, go to chapter 4 of the LTM manual: https://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/LTM_config_guide_943/ltm_pools.html?sr=18269610

     

     

    I hope this is a more elegant solution for you.

     

     

    Cheers,

     

    Helen