Security is a fundamental aspect of any network infrastructure. The goal is to always have the most up to date programs and protocols to ensure the protection of the network. No aspect is too small to over look. That could mean the difference between a secure network and a compromised network. The best way to achieve this is to break down every level and approach each one as a separate entity and secure it. Then you can modify it to suit the needs of your network.
We can start with the Application layer. The Application layer provides the interface to the user. First the end user should be subjected to a background check to ensure against any potential malicious or questionable acts in the users past. Then the end user should be properly trained in the use of the computer and the proper protocols to access the network. Updates should be made frequently to keep the user up to date. When the user is in the network, make sure that any unnecessary devices, USB ports and any back doors are disabled. You also want to make sure that all files and emails and downloadable attachments are all thoroughly scanned prior to downloading. Finally, be sure to ensure content filtering, and restrict the end user to only what pertains to their primary function.
The Presentation layer is responsible for encoding and decoding data that is passed from the application layer to another station on the internetwork. You must first ensure that all USB ports are disabled, as well as CD and DVD. This helps to prevent any unauthorized uploads or downloads Make sure that any devices that are not pertinent to the user are disabled as well. To prevent any downloads, use filtering and antivirus scanning. Make sure that any external devices are not used unless proper authorization is obtained. Update all software regularly and enable password protection and screen lock out when the computer is inactive.
The session layer is responsible for creating, managing and terminating sessions that are used by entities at the presentation layer. First you must secure the physical part by making sure that your closets are secure under lock and key and video monitored as well. Make sure that you have an access list of personnel authorized into the closet and keep a log of all who access the closets. Use the highest key possible for all wireless access points. Finally, make sure that all the work stations are individually encrypted as well. You could use two forms of authorization at the users work station.
The Transport layer implements reliable internetwork data transport services that are transparent to upper-layer protocols. First you want to disable ping, probing and port scanning on all the IP devices in the LAN to WAN, this helps prevent phishing and trolling for open ports or any vulnerabilities in the network. you also need to make sure you disable all IP port numbers and monitor with intrusion detection and intrusion prevention systems. You would also like to monitor all of the inbound traffic for any questionable items and apply file transfer monitoring, scanning, and alarming for unknown files. Finally, you should continuously check for vulnerabilities and fix them when they are found, and ensure domain name content filtering is used to keep users on task.
The Network layer defines routing services that allow multiple data links to be combined into an internetwork. You should first restrict using the internet for private communications, set permissions to deny any social or streaming web sites or pages. Then put firewalls in place and apply Acceptable Use Policy in accordance to the RFC 1087: Ethics and the internet. Then get your ISP to put the proper filters on its IP router interfaces. Finally, you should back up all data in an offline, and of site location. Be sure to scan all email attachments for possible threats to the network.
The Data Link layer provides reliable transit of data across a physical network link. The Data Link layer also defines the physical network-addressing scheme, such as the MAC Address on network interface cards in a workstation connected to a LAN. First you should encrypt all confidential data transmissions through the service provider. You should also make sure that your access control lists are enabled and implement continuous SNMP alarms and security monitoring.
The Physical layer defines the parameters necessary to build, maintain, and break the physical link connections. First set automatic blocking for attempted logon retries, this will help against dictionary attacks. You could also apply first-level and secondary level security for remote access to sensitive systems. Be sure to encrypt all private data within the database or hard drive. Finally apply real-time lockout procedures if a token is lost or device is compromised.
Part 2: Student SSCP Domain Research Paper
This is a multi-layered security plan. First, Assign people that are fully trained and/or provide the training that makes it possible to do the job. To prevent malicious software and etc. in the 7 domains of an IT infrastructure, you can isolate and install preventions for each domain. The domains are as follows: User Domain, Workstation Domain, LAN Domain, and LAN to WAN Domain, Remote Access Domain, WAN Domain, and the System/Application Domain.
The first part of the IT infrastructure is the User Domain. It is the weakest link in the IT infrastructure and this is where the users connect to the system. You can make the user aware to the risks and threats that they are susceptible to by holding an Awareness Training session. The system is password protected however; you should change passwords every few months to prevent an attack. Also, log the users as they enter and exit the system to make sure theres no unauthorized access. While its the companys choice to allow employees to bring in USB/Removable drives, you have a threat to someone obtaining the wrong information, or getting malicious software into the system. If you allow the USB/Removable drives, have a virus scan every time someone inserts one into a company computer.
In a Workstation Domain, you need to make sure virus protection is set up. You are protecting administrative, workstations, laptops, departmental workstations and servers, network and operating system software. You can enable password protection and auto screen lockout for inactive times, use workstation antivirus and malicious code policies, use content filtering and antivirus scanning at internet entry and exit, and update application software and security patches according to the policies and standards. You need to also make sure that the laptops are up to date on the anitivirus software.
The LAN domain will have all the protocols for the users to make sure that they are authorized to access those areas. Make sure that the server rooms are locked and wireless access points are password protected. A LAN to WAN domain is where the IT infrastructure links to a wide area network and the internet. To prevent any problems make sure you apply strict security monitoring controls for intrusion detection, apply file transfer monitoring, and disable ping, probing and port scanning on all exterior IP devices within this domain and have an alert system when someone plugs in a removable media disk(since they are not allowed). If a problem occurs, fix it fully to make sure it doesnt happen again.
In a WAN Domain, make sure to implement encryption and acceptable use policies. Scan all email attachments and prohibit the internet for private communication (if possible). Make sure security policies are being followed and every employee is in compliance and signs an acceptable use policy. You can allow only access to the mainframe from the job site or on an acceptable laptop.
For the Remote Access Domain, you need to focus on password attempts and encryption. First, you need to apply a user id and password. Then, limit the number of times that a user can enter his or her password before it locks out. Also, apply time lockout procedures on confidential data and make sure you encrypt also. Make sure you have qualified people doing their jobs correctly since they will have remote access to other peoples computers.
In a System/Application Domain, it holds all the mission critical systems, such as, operating system software, applications, and data. To prevent any virus, malware, or unauthorized access into your system, apply a code of ethics, and implement daily backups. Also, apply polices, standards, and guidelines for all employees who enter and exit the building, make sure all server rooms are secure and that only the people that have access to them are entering them.
In conclusion, encryption is a big part of domain security, along with firewalls and doing virus and malware scans. As long as you cover the major aspects and security measures listed in this document, that will be a big plus for your company.