Problématique et concepts de base

Avoid to put in the same area entities which have very different security requirements

Using proxies (I)

• Proxies can be used to « hide » the real servers/the real network

• Exterior => Interior traffic

• Gives the external user the illusion that she/he accesses to the interior server
• But intercepts the traffic to the server, analyzes the packets (checks the compliance with the protocol, searches for keywords, etc.), logs the requests

• Interior => Exterior traffic

• Give the internal user the illusion that she/he accesses to the exterior server
• But intercepts the traffic to the server, analyzes the packets (checks the compliance with the protocol, searches for keywords, etc.), logs the requests

Using proxies (II)

• Advantage

• knowledge of the service/protocol => efficiency and « intelligent » filtering
• Ex : session tracking, stateful connection
•