What technologies allow intranet machines to connect to the Internet?

• A. Mediation servers like IRC, Usenet, SMTP, Proxy server, NAT, and Tunneling protocol.
• B. VPN, firewall, and IDS only
• C. A single gateway router
• D. Local services only

Answer: (A)

Connecting intranet machines to the Internet relies on mechanisms that translate addresses, mediate traffic, and, when needed, encapsulate it for traversal across networks. NAT lets many private hosts share a single public IP by translating internal addresses as traffic leaves the intranet. A proxy server forwards requests to the Internet on behalf of internal clients, enforces access policies, and can cache content. Tunneling protocols, such as those used for VPNs, create secure channels that carry intranet traffic across network boundaries. Together, these technologies enable intranet users to reach external resources while maintaining control and security.

Security devices like VPNs, firewalls, and IDS are important for protection but don’t by themselves provide the full set of mechanisms needed for general Internet connectivity. A single gateway router might enable basic access, but without NAT and proxying, address translation and traffic mediation aren’t handled. Local services only cannot reach external networks at all.