# A Survey on Intrusion Detection Systems for Fog and Cloud Computing
## 8 Case Studies
### Adopting Content for Teaching and Learning in Higher Education
#### 8.1.3 Xiang'an Campus of Xiamen University  
Located in Xiamen, this campus was built in the 1950s and had over 20 low-rise buildings. It has its own independent financial and personnel systems and a range of student admissions, administration, and logistics services management systems, its own library and modern education center, and is a relatively independent branch campus. Relative to the size of other campus networks, the campus network is small, but there are distinctive features. First, the campus network has a large and dense user base. Students live in centralized accommodation and have regular working and resting hours; therefore, their internet access is relatively concentrated. The high broadband and large user base provide favorable conditions for the rapid spread of network security issues. Secondly, as the campus has many buildings, but fewer floors per building, the campus network of the college adopts a two-layer network topology, i.e., a core layer and access layer, with no convergence layer. However, the access is complex and there is no single outlet. The coexistence of LAN, MAN, and WAN in the campus network makes it necessary for campus managers to face a complex network environment. Thirdly, the campus network is open and more relaxed. To facilitate access to the internet for students without computers, the college has a computer room with direct access to the campus network. This open network environment is also fraught with hidden dangers. Fourthly, user identities are complex and mobile, and pirated software, film, and TV resources, as well as all kinds of shareware, are prevalent in the campus network, providing opportunities for network viruses to invade. Fifth, many of the campus's network hardware devices are exposed to the public space of the campus and are vulnerable to natural disasters and human damage.  
In order to combat the above issues, as a part of the security system of the campus network, this campus has deployed a firewall and intrusion detection system (IDS) from Tianrongxin at the central exit of the network. The intrusion detection system captures and monitors the transmission of data on the campus network in real time, deeply inspects all packets entering the campus network, detects whether DMZ servers and data center applications are under attack, audits malicious port scanning and probing behavior, and implements supervision of all activities on the network. As soon as a potential threat is detected, the system sends out an alert to notify the relevant management. It alsoprevents some wrong actions, generates log files for analysis, detects intrusions against the network and servers in real time, and makes up for the lack of equipment such as routers, firewalls, and switches. Physical security avoids damage to network equipment from natural disasters and environmental incidents, ensuring that it is protected from dust, lightning, and static electricity, and especially from deliberate human damage. Xiamen is a typhoon-prone and humid city, and the campus's short buildings have a negative impact on the physical protection of network equipment. Therefore, the campus places servers and core switches on the third floor and builds network cabinets according to relevant standards. It also sets up dedicated equipment grounding cables and equips them with uninterruptible power supplies to ensure that equipment has a continuous and stable power supply and is not affected by external power supplies. The batteries are also regularly maintained following the requirements of the operating code. Moreover, air conditioning is installed to maintain a certain temperature and humidity [53].