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Khun_Sophavatta's avatar
Khun_Sophavatta
Icon for Nimbostratus rankNimbostratus
Jul 19, 2026

Can BIG-IP perform DNAT before Virtual Server lookup?

Hi everyone I have a question about BIG-IP packet processing. As I understand it, the destination IP received by BIG-IP must match a configured Virtual Server. This can happen either because: - Th...
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Daniel_Wolf's avatar
Daniel_Wolf
Icon for MVP rankMVP
Jul 19, 2026

Hi Khun_Sophavatta​,

The BIG-IP uses the destination address, source address, and service port to match incoming traffic to a virtual server.
But also the BIG-IP is a default deny device. This means, when no traffic processing objects are configured (for example a matching virtual server), the BIG-IP system does not process any network traffic. 
For your question this means - the destination IP must match the Virtual Servers IP address, otherwise the BIG-IP won't do much with it.

Can you explain what you plan to do? Maybe we can suggest a solution.

Cheers
Daniel