Forum Discussion

Altostratus

Dec 16, 2007

Virtual IP's and Floating IP's

Hi, Apologies in advance, this is not an advanced question, however I'm not sure what other forum to use for general LTM type questions. My question is this: In a typical 2 ar...

config

design

hoolio

Cirrostratus

Dec 18, 2007

Hello,

While it might be technically possible to configure a virtual server using the same IP address as a self IP, it's not advised. The self IP's should be used only for sourcing load balanced traffic or receiving admin traffic.

Typically, you would configure a floating self IP on a VLAN if you want to always have client traffic which is sent out that VLAN sent from the same IP address, regardless of which unit is active. If hosts behind the BIG-IP communicate through the BIG-IP to the external VLAN using a SNAT object, you could configure a floating self IP on that VLAN to ensure that SNAT'd traffic always has the same source IP regardless of which unit is active.

In earlier versions (9.0.x), I remember seeeing cases where TMM would use the floating self IP from the internal VLAN as a source address if a floating self IP wasn't defined on the external VLAN. I think that was considered a bug and fixed though.

Aaron