In the second half of 2022, the afternoon real questions and answers for information security engineers

Question 1 (20 points)

It is known that the network environment structure of a company is mainly composed of three parts, namely the DMZ area, intranet office area, and production area. The topology structure is shown in Figure 1-1. Wang Gong of the Information Security Department is carrying out security configuration for some business systems in accordance with the requirements of Level Protection 2.0. In Figure 1-1, the IP address of the website server is 192.168.70.140, the IP address of the database server is 192.168.70.141, the network segment where the computer of the Information Security Department is located is 192.168.11.1/24, and the IP address of Wang’s office computer is 192.168 .11.2.

Question 1 (2 points)

In order to prevent the production network from being threatened by external network security, the security policy requires the deployment of security isolation devices between the production network and other networks, and the isolation strength is close to physical isolation. What is the security device most likely represented by X in the picture?

Question 2 (2 points)

Firewall is an important technology for border protection of network security areas. Firewall defense architecture mainly includes dual-homed host firewall, proxy-based firewall and shielded subnet-based firewall. Which architecture type does the firewall layout in the topology diagram in Figure 1-1 belong to?

Question 3 (2 points)

Usually network security needs to establish four lines of defense. The first is protection to prevent network intrusion; the second is monitoring to detect intrusions and damages in time; Recovery, allowing the network to come back to life as quickly as possible in the event of an attack. What line of defense does firewall 1 belong to in topology diagram 1-1?

Question 4 (6 points)

Both firewall 1 and firewall 2 in Figure 1-1 use the iptables firewall that comes with the Ubuntu system, and their default filtering rules are shown in Figure 1-2.