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Amnard's avatar
Amnard
Icon for Nimbostratus rankNimbostratus
Nov 13, 2012

ARP table changes between reboot

It's annoying that I have to clear the ARP table every time I reboot the F5 standalone unit or both units in HA config.

 

Is there a setting where the F5 MAC addresses in the ARP table be static or persistent between reboot?

 

config
design

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  • What_Lies_Bene1's avatar
    What_Lies_Bene1
    Icon for Cirrostratus rankCirrostratus
    Nov 13, 2012
    The ARP table is dynamic and should be cleared on a reboot. Static entries can be configured but I'm assume you've not done so. It's possible the Reciprocal Update feature is populating the ARP table very quickly and you could always disable that feature.

     

     

    Why do you need to clear the table anyway?
  • Amnard's avatar
    Amnard
    Icon for Nimbostratus rankNimbostratus
    Nov 13, 2012
    When an F5 box is rebooted, VS are no longer accessible due to MAC addresses change. I have to flush the ARP tables on the devices that F5 box is connected to. Just to be clear, ARP entries on the F5 box themselves are not the problem, but what other devices see after the reboot is the problem.

     

     

    Note: we don't use F5 for routing traffic.
  • What_Lies_Bene1's avatar
    What_Lies_Bene1
    Icon for Cirrostratus rankCirrostratus
    Nov 13, 2012

    OK, understood. I can't imagine why the MAC addresses would change on a standalone device for any reason.

     

     

    They might on a HA pair if the active/standby role changes but this is easily overcome by using MAC-Masquerade with the floating Self IP, assuming you're using one? Based on some of your comments in earlier forums, I suspect not!