What is the first line of defense when an organization is using a defense-in-depth approach to network security?proxy serverIPSfirewalledge router

In a defense-in-depth approach to network security, the first line of defense is typically the edge router. Here’s a step-by-step explanation:

1. Edge Router: This is the first device that connects the internal network to the external internet. It is responsible for routing traffic and often includes basic filtering capabilities to block unwanted traffic from entering the network.

2. Firewall: After the edge router, the firewall provides a more detailed level of security by monitoring and controlling incoming and outgoing network traffic based on predetermined security rules.

3. Proxy Server: This acts as an intermediary for requests from clients seeking resources from other servers. It can provide additional security by filtering content and hiding the internal network's IP addresses.

4. Intrusion Prevention System (IPS): This system monitors network traffic for suspicious activity and can take action to prevent potential threats. It is typically placed behind the firewall and proxy server to provide deeper inspection and protection.

In summary, the edge router is the first line of defense in a defense-in-depth strategy, followed by the firewall, proxy server, and IPS.