# Deploying Secure Distributed Systems: Comparative Analysis of GNS3 and SEED Internet Emulator
## 6 Results and Evaluation
### Cost Evaluation
#### 6.4.3 Maintenance and Reliability  
Computer network maintenance involves monitoring, updating, and running the network to prevent issues from arising. However, it is important to consider the cost implications associated with network maintenance. The cost considerations include the following:  
* **Network security**: Ensuring a secure network environment by implementing contemporary and robust defense systems and mechanisms, such as access control, intrusion detection, and firewalls. The cost of acquiring and maintaining security solutions, as well as the associated personnel required to manage them, should be considered. In GNS3, these security measures can be implemented by integrating specific appliances such as pfSense, which can be attached to the network to provide firewall functionality and other security features. Similarly, the SEED Internet Emulator allows the use of programmable code integrated into the emulated network, which enables the deployment of various firewall software and other security solutions. Both platforms offer flexibility in choosing appropriate security solutions to protect the emulated networks effectively. By investing in robust security measures, potential threats can be mitigated, and the overall network resilience and data protection can be significantly enhanced. * **Network performance**: Ensuring the optimal network speed and reliability of devices, which includes managing bandwidth usage and minimizing delay times. * **Network scalability**: Ensuring that the network design and nodes can accommodate the operational demands, such as the number of users, locations, and business functions. To achieve this, it is essential to design the networks with scalability in mind. For instance, using open-source communication protocols such as OSPF can facilitate multi-vendor networking, and in GNS3 and the SEED Internet Emulator, designing the network to allow for the easy attachment of additional nodes contributes to scalability. * **Hardware and software updates**: Regularly updating both the hardware and software elements of the network is crucial for maintaining security, performance, and compatibility. This involves ensuring all hypervisors and Virtual Machines (VMs) are kept up-to-date, along with the platforms running the emulated network. * **Infrastructure compliance**: Ensuring that the network adheres to relevant policies and legislative requirements. This includes meeting security standards, data protection regulations, and any other compliance obligations applicable to the specific network environment. * **Network repairs**: Proactively identifying and resolving problems before they escalate is essential for network stability. This can involve implementing measures such as regularly backing up GNS3 project files to prevent data corruption and creating copies of the code used for SEED Internet Emulator deployments, allowing for easy recovery in case of issues. Computer reliability is a crucial characteristic of any computer-related component, encompassing software, hardware, and networks. A reliable system should demonstrate dependability, characterized by high uptime, low downtime, and minimal system failure rates. To ensure this, the following metrics can be monitored:  
* **System availability**: This metric represents the ratio of the system's actual operating time to the total time it is expected to be available. Ensuring availability in GNS3 requires attention to various factors, such as the GNS3 VM (GNS3 server)--which stores and runs all virtual devices, VMs providing services, and network nodes. Regular audits should be conducted to ensure all components of the emulated network are in optimal condition. On the other hand, the SEED Internet Emulator does not depend on decentralized factors such as external VMs. However, it is essential to take precautions to secure all the relevant files required for emulation. Any accidental removal, corruption, or unauthorized access to these files could potentially lead to system unavailability.