Problématique et concepts de base

Firewalls : usages

• Access control : usage restriction on some protocols/ports/services

• Packet filtering

• Authentication : only authorized users and hosts (machines)

• Monitoring for further auditing

• Compliance with the specified protocols

• Virus detection

• Isolation of the internal network from the Internet

• Data encryption

• Connection proxies (masking of the internal network)

• Application proxies (masking of the « real » software)

Firewalls : architecture (I)

Firewalls : architecture (VI): managing an internal FW

Firewalls : some recommendations

• Bastion hosts

• better to put the bastions in a DMZ than in an internal network
• disable non-required services
• do not allow user accounts
• fix all OS bugs
• safeguard the logs
• run a security audit
• do secure backups
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