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DavidB's avatar
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Jun 23, 2022

Load Balance Host Headers

I posted last week asking for assitance load balancing WebLogic apps. I received some good responses, but they didn't work. I submitted an F5 support case and was basically told they don't help build new configurations, only fix "broken" ones and I should use professional services. I found some third party WebLogic admin books that suggest load balancers should NOT replace proxies, but be used with them.

So my current isue. I had an existing IIS server using host headers to accept the incoming requests, handle SSL requirements and proxy (forward) HTTP requests to some WebLogic nodes.

I changed DNS and put F5 in front of this (still using a single VIP entry point) to route to the same IIS box then proxy to WebLogic. With this setup I have a few sites (4 out of 11) that seem ok. The rest show infinite loops on the redirects. I've rechecked the IIS config multiple times to make sure the SSL redirects were removed and sites are now HTTP only. The IIS logs seem to show that the traffic actually never gets to the IIS server. I can't seem to figure out how I introduced this redirect. I'm wondering if I need to remove the idea of "host headers" on IIS or F5 or both to get this stable and working.

8 Replies

  • Are you able to post the configuration of one of your looping virtual servers?

    Maybe I can find the issue.


    • DavidB's avatar
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      Hi, Are you asking for the iApp or VS on the F5 or the IIS? I suppose I could figure out how to export the full configuration and share it for review. When I was debugging the new setup yesterday I wasn't actually seeing any evidence that the traffic got past the F5. I think my redirect loop might be occurring there. I'm going to try a wireshark capture this morning on the IIS server to see if I can confirm this.

  • Only one of the virtual servers that is redirecting.
    Command is list ltm virtual <name of virtual server>

    • DavidB's avatar
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      Thanks for clarifying. I should be clear though, I am using one VS on F5 and a shared IP on IIS to support IP sharing on both devices. My VS looks like this:

      ltm virtual {
      app-service /Common/
      creation-time 2022-06-17:09:53:43
      ip-protocol tcp
      last-modified-time 2022-06-24:10:25:24
      profiles { {
      context clientside
      } {
      context serverside
      } {
      context clientside
      } { } { } { } { }
      rules {
      serverssl-use-sni disabled
      source-address-translation {
      type automap
      translate-address enabled
      translate-port enabled
      vlans {
      vs-index 21


      The iApp has all the DNS names attached to it and I have an iRule for handling the redirects to URLs that IIS will then proxy to the WebLogic.

      I did start my captures on IIS and did find that I missed some of the require SSL settings so at least some of my failed tests are my own stupidity and lack of quality control. I'm still reviewing. However, I'm now questioning this configuration and if it's something that F5 really isn't going to handle well. If I'm forced to request a bunch of new IPs and DNS entries to make this work properly I can abondon this effort and start that approach.