Cisco weird interfaces, nvi, svi, bvi

NVI – NAT Virtual Interface

Not everyone knows that from IOS version 12.3(14)T, Cisco has introduced a new feature called NAT Virtual Interface; NVI removes the requirements to configure an interface as either NAT inside or NAT outside. An interface can be configured to use NAT or not use NAT.

How to use NVI? It’s easy! You must use the command ‘ip nat source …’ without specifying the inside/outside tag and enable the nat to the interfaces using the command ‘ip nat enable’. Continue reading