Forum Discussion

peter_71591's avatar
peter_71591
Icon for Nimbostratus rankNimbostratus
Mar 21, 2012

Recommendation needed

Hi, I'd like to know whether F5's can do the following. I have two servers I want to keep in sync (see exactly the same traffic) they must be seen as one machine from the outside world. So they would both receive the same data, and both reply, but the reply from only one would be sent to the client. I am not sure about the technical terms for all this, I am a newbie. Also the F5's would have to be redundant, so if one failed the other would take over seamlessly. If one of the servers fails the F5's would detect this and keep the connections going so the outside world wouldn't know that anything had happened.

thanks.

 

basic
getting started
new to f5

2 Replies

  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    Mar 21, 2012
    Hi Peter,

     

     

    What protocol(s) do you want to do this for? For HTTP you can clone requests to a second pool. Requests are copied and responses from the second pool are dropped.

     

     

    HTTP Request Cloning via iRules

     

    http://devcentral.f5.com/Tutorials/TechTips/tabid/63/articleType/ArticleView/articleId/1088513/HTTP-Request-Cloning-via-iRules-Part-1.aspx

     

     

    It should be possible to do something similar for generic TCP and/or UDP traffic using high speed logging.

     

     

    If the first server is down, you could send all requests to the second pool. And generally BIG-IP's are deployed in an HA pair, so redundancy at that level is taken care of.

     

     

    Aaron
  • Hamish's avatar
    Hamish
    Icon for Cirrocumulus rankCirrocumulus
    Apr 17, 2012
    Your switch can also probably do this with a SPAN (Cisco terminology) or RSPAN session. At the switch level you have the advantage of capturing anything that hits the server that doesn't pass through the BigIP.

     

     

    H