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Brandon_12607's avatar
Brandon_12607
Icon for Nimbostratus rankNimbostratus
Jul 12, 2018

Mirroring Setup General Knowledge

Couple questions about Mirroring on HA Pair Do you only enable or use mirroring for persistence? We use snat or snat pools on most every VIPs and are one arm environment mostly.

 

4 Mirrioring Settings/options Device Cluster VIP SNAT Persistence Profile

 

Usually have muptile Vlans and floating and nonfloating SelfIPs Under Cluster options Netwrok Mirroring Within Cluster (This IP will be Different then the Self IPs and VLans) Primary local and secondary local.

 

VIP Normally required enable connection Mirroring?

 

Local trafic>> Address tranaslation>>>Snat list>>> New Snat== Check the Stateful failover Mirror ? When should i use this no clue????

 

Persistence Connections ? DO you have to enable this to mirror Persistence connections Universal and other persistence profiles Mirror Persistence check

 

APM
application delivery
LTM

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  • KevinA_246454's avatar
    KevinA_246454
    Icon for Cirrostratus rankCirrostratus
    Jul 12, 2018

    HI Brandon

     

    Mirroring, in my view is basically needed for a state-full fail over in your HA cluster. For it to be state full the standby device needs to know about the active connections on the active device.Also persistence mirror gives the flexibility of the when a session is no longer active for example user logged of the online clothing store with a cart full of items, when that same user log in again 2 minutes later (in which time my devices failed over) The now active ltm will send the user to the initial back end server he logged in before the 1st session closed, but you will have to consider the application it self. HTTP I am sure a quick 3way handshake will just continue a failover session when my active box fails, but a telnet or ssh session wont.

     

    Mirroring configuration you will need depending your level of failover you need in your HA cluster, on the virtual server for the active connections, on the SNAT configuration for routing purposes I guess, and the actual persistence record as explained above. hope my input helps.

     

  • boneyard's avatar
    boneyard
    Icon for MVP rankMVP
    Jul 14, 2018

    you use mirroring for two things

    • connection mirroring

    that is mainly just keep the session table in sync so sessions don't have to be rebuilt after the failover

    • persistence mirroring

    that is for making sure persistence information is also in sync. not required for some types of persistence, where no persistence state is saved on the BIG-IP, i.e. cookie persistence.

    for more information and configuration see: https://support.f5.com/csp/article/K13478

    i don't totally understand your exact questions but ill try

    VIP Normally required enable connection Mirroring?

    require is a big word, it helps during a failover, but do see some notes about it not working for everything, i.e. FTP, ASM module, ...

    SNAT: When should i use this no clue????

    if you want the connections from the SNAT address to be also mirrored to the standby box, so during a failover the impact is lower

    Persistence Connections ? DO you have to enable this to mirror Persistence connections Universal and other persistence profiles Mirror Persistence check

    little lost at where you now are in the configuration