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axa0176_2322
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Nov 23, 2010

Floating IPs and MAC Masquerade Question

Hi guys,

 

 

I'm relatively new w/ application layer load balancing and I had a question about the documentation I was reading on floating IPs and MAC Masquerading. Here are my questions:

 

 

 

 

 

1. In a high availability setup, is the floating IP used by default ?

 

 

 

2. Does the floating IP have its own MAC address or does it use the MAC address of the currently active system?

 

 

 

2. Does configuring a floating IP in a high availability setup implicitly configure a MAC masquerade?

 

 

 

 

 

 

 

Thanks in advance!

 

1 Reply

  • 1. In a high availability setup, is the floating IP used by default ?

     

     

    LTM will source traffic configured for SNAT automap from floating self IP's. Monitor and other admin traffic going out a switch port will use a static (non-floating) self IP address.

     

     

    2. Does the floating IP have its own MAC address or does it use the MAC address of the currently active system?

     

     

    By default, there is one MAC address per VLAN per LTM unit. All self IP addresses on that VLAN on a given unit will share the same MAC address. By default, no MAC addresses are the same between two units. MAC masquerading can be used to specify a custom MAC address that both units share for floating IP addresses.

     

     

    3. Does configuring a floating IP in a high availability setup implicitly configure a MAC masquerade?

     

     

    No, see 2 above.

     

     

    See SOL7214 for details on selecting a MAC address and configuring MAC masquerading:

     

     

    SOL7214: Configuring MAC masquerading

     

    http://support.f5.com/kb/en-us/solutions/public/7000/200/sol7214.html

     

     

    Aaron