Problématique et concepts de base

Disadvantages

• one proxy per service !
• may require modifications of the client
• do not exist for all services

Static Network Address Translation (NAT) (I)

The FW maintains an address translation table

• The FW maintains an address translation table

• The FW transforms address xxx.xxx.xxx.xxx into yyy.yyy.yyy.yyy in the field « source address »

• The FW transforms address yyy.yyy.yyy.yyy into address xxx.xxx.xxx.xxx in the field « destination address »

• This operation is transparent for both the exterior and the interior hosts

Static Network Address Translation (NAT) (III): Applications

• Non TCP/UDP based protocols

• Pre-defined partnership addresses - Host known/authenticated outside the LAN with a specific address

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