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aLuViAn_187519's avatar
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Feb 15, 2015

How to setup F5 Big-IP LTM for Weblogic on different ports, same IP

Hi Everyone,


I am a Weblogic/Oracle DB administrator. Currently we are establishing our web application on a Weblogic Cluster using two redundant Big-IP 1600 LTM devices. We have a 9-node Weblogic cluster on 3 different AIX 7.1 machines (each machine has 3 different Virtual Servers). Our F5 consultants have asked us to establish our Virtual servers on different IPs due to some constraints on F5 LTM that you cannot have more than one pool member with the same IP. So we tried multihoming on our cluster (to use more than one NIC with different IP addresses and bind each Weblogic Virtual Server to each one of them) but later we found out that multihoming causes issues with Weblogic internal messaging system. What we are currently looking at is to have one IP per machine and running our Virtual Servers on a different port. But it seems it causes issues for F5 in configuration. How we can deal with this? Anyone has any ideas?


So far, I've found two solutions : IP teaming and reverse proxy, we are still investigating these two but due to some project constraints we might not be able to proceed with these two. I wanted to know if there is something inside F5 (like iRule) to direct the requests to different VIP/Ports.


Let me know if "any" ideas on "any" layers came into your mind!


6 Replies

  • single node, with two different pools, each has its related service port, then two virtual servers utilizing the pools, respectively


  • THi's avatar
    Icon for Nimbostratus rankNimbostratus

    There are two concepts:


    • a node which is an IP address, typically a physical or virtual server instance


    • a member which is a combination of IP address and port (port can also be any (0 or wildcard meaning all ports)), typically an application instance behind the IP address:port listener in a server


    A load balancing pool has members, not nodes. You can have three members in a pool, all having same IP address but each a different port.


    Thus you scenario of three physical nodes (=3 IP addresses), each having 3 WebLogic instances listening on different ports is feasible. You can have all those 9 members in the same load balancing pool.


  • Let me give you a better understanding. Initially we had the following setup of our Weblogic cluster:


    On machine 1 : x.x.x.10:10010 x.x.x.10:10020 x.x.x.10:10030


    On machine 2 : x.x.x.11:10040 x.x.x.11:10050 x.x.x.11:10060


    On machine 3 : x.x.x.12:10070 x.x.x.12:10080 x.x.x.12:10090


    Then , after the first consultant, we had this:


    On machine 1 : x.x.x.10:10010 x.x.x.11:10010 x.x.x.12:10010


    On machine 2 : x.x.x.13:10010 x.x.x.14:10010 x.x.x.15:10010


    On machine 3 : x.x.x.16:10010 x.x.x.17:10010 x.x.x.18:10010


    Which caused us problems, now we have :


    On machine 1 : x.x.x.10:10010 x.x.x.10:10020 x.x.x.10:10030


    On machine 2 : x.x.x.11:10010 x.x.x.11:10020 x.x.x.11:10030


    On machine 3 : x.x.x.12:10010 x.x.x.12:10020 x.x.x.12:10030


    I understand there is no limitation on any of the setup of IP/port above. I just want to know which one is "most suitable" for F5. Except the second one (Multihomed servers) the others are OK for Weblogic, and also changing them won't take that long.


  • Actually we have had a lot of problems with our previous F5 consultant, he claimed that we cannot have different ports on one IP for service because F5 does not translate the port, just the IP, so we had to add more NICs and use the same port for each of our Virtual instances of Weblogic which created a bunch of problems for us.


    By the way, will there be any consideration for Load balancing and failover when we have separate pools with the same pool member? Or it just works fine?


    • StephanManthey's avatar
      Icon for MVP rankMVP
      Hi aLuViAn, by default a virtual server (of type host) does both address and port translation. It is possible, to combine servers with same IP but different ports in the same pool. Depending on load balancing method and persistence settings incoming traffic will be forwarded to the available pool members and destination address and port translation will be applied. Persistence records will be set accordingly. Perhaps I misunderstood your question. But I don´t see a reason to create multiple virtual servers and pools. And as NikhilB already pointed out, it is possible as well use the same pool member address-port combinations simultaneously in multiple pools. Thanks, Stephan
  • our Virtual servers on different IPs due to some constraints on F5 LTM that you cannot have more than one pool member with the same IP.


    What constraints are you referring to? You can create separate pools with the same pool member. You can have a node listening on a different service and in a different pool.