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randyw_75267's avatar
randyw_75267
Icon for Nimbostratus rankNimbostratus
Mar 21, 2008

NAT/SNAT + routing order of operations

Hi folks,     Very new to F5, and trying to get a handle on some of the order of operations for traffic flow types. Specifically, I'm curious to see how layer 3 routing is handled by BigIP devic...
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Deb_Allen_18's avatar
Deb_Allen_18
Historic F5 Account
Mar 28, 2008
Hi Randy -

 

 

Thanks for posting, great question.

 

 

For LTM, inbound & outbound flows aren't managed separately and routing will take place after NAT/SNAT/dest translation is performed in all cases.

 

 

Traffic flows from the client to LTM VS address or SNAT with a matching origin address, then source and destination address changes are applied, then the routing table is used to determine the egress vlan.

 

 

It's worth noting that the Last Hop feature is enabled by default, which keeps track of the L2 source of a request and returns responses to the same L2 hop in precedence of the routing table logic.

 

 

HTH

 

/deb