Network Security Model – Defining an Enterprise Security Strategy


These are the 5 main safety teams that needs to be thought-about with any enterprise safety mannequin. These embody safety coverage, perimeter, community, transaction and monitoring safety. These are all a part of any efficient firm safety technique. Any enterprise community has a fringe that represents all gear and circuits that connect with exterior networks each private and non-private. The inner community is comprised of all of the servers, functions, knowledge, and units used for firm operations. The demilitarized zone (DMZ) represents a location between the interior community and the perimeter comprised of firewalls and public servers. It that enables some entry for exterior customers to these community servers and denies visitors that may get to inner servers. That doesn’t suggest that every one exterior customers can be denied entry to inner networks. On the opposite, a correct safety technique specifies who can entry what and from the place. For occasion telecommuters will use VPN concentrators on the perimeter to entry Windows and Unix servers. As nicely enterprise companions may use an Extranet VPN connection for entry to the corporate S/390 Mainframe. Define what safety is required in any respect servers to guard firm functions and information. Identify transaction protocols required to safe knowledge because it travels throughout safe and non-safe community segments. Monitoring actions ought to then be outlined that look at packets in actual time as a defensive and professional-energetic technique for safeguarding in opposition to inner and exterior assaults. A latest survey revealed that inner assaults from disgruntled workers and consultants are extra prevalent than hacker assaults. Virus detection ought to then be addressed since allowed classes may very well be carrying a virus on the utility layer with an e-mail or a file switch.

Security Policy Document

The safety coverage doc describes numerous insurance policies for all workers that use the enterprise community. It specifies what an worker is permitted to do and with what assets. The coverage contains non-workers as nicely comparable to consultants, enterprise companions, shoppers and terminated workers. In addition safety insurance policies are outlined for Internet e-mail and virus detection. It defines what cyclical course of if any is used for inspecting and enhancing safety.

Perimeter Security

This describes a primary line of protection that exterior customers should take care of earlier than authenticating to the community. It is safety for visitors whose supply and vacation spot is an exterior community. Many parts are used to safe the perimeter of a community. The evaluation evaluations all perimeter units at present utilized. Typical perimeter units are firewalls, exterior routers, TACACS servers, RADIUS servers, dial servers, VPN concentrators and modems.

Network Security

This is outlined as all the server and legacy host safety that’s carried out for authenticating and authorizing inner and exterior workers. When a person has been authenticated by perimeter safety, it’s the safety that have to be handled earlier than beginning any functions. The community exists to hold visitors between workstations and community functions. Network functions are carried out on a shared server that may very well be working an working system comparable to Windows, Unix or Mainframe MVS. It is the duty of the working system to retailer knowledge, reply to requests for knowledge and keep safety for that knowledge. Once a person is authenticated to a Windows ADS area with a selected person account, they’ve privileges which were granted to that account. Such privileges could be to entry particular directories at one or many servers, begin functions, and administer some or all the Windows servers. When the person authenticates to the Windows Active Directory Services distributed it isn’t any particular server. There is great administration and availability benefits to that since all accounts are managed from a centralized perspective and safety database copies are maintained at numerous servers throughout the community. Unix and Mainframe hosts will normally require logon to a selected system, nevertheless the community rights may very well be distributed to many hosts.

· Network working system area authentication and authorization

· Windows Active Directory Services authentication and authorization

· Unix and Mainframe host authentication and authorization

· Application authorization per server

· File and knowledge authorization

Transaction Security

Transaction safety works from a dynamic perspective. It makes an attempt to safe every session with 5 main actions. They are non-repudiation, integrity, authentication, confidentiality and virus detection. Transaction safety ensures that session knowledge is safe earlier than being transported throughout the enterprise or Internet. This is vital when coping with the Internet since knowledge is susceptible to those who would use the precious data with out permission. E-Commerce employs some trade requirements comparable to SET and SSL, which describe a set of protocols that present non-repudiation, integrity, authentication and confidentiality. As nicely virus detection gives transaction safety by inspecting knowledge information for indicators of virus an infection earlier than they’re transported to an inner person or earlier than they’re despatched throughout the Internet. The following describes trade normal transaction safety protocols.

Non-Repudiation – RSA Digital Signatures

Integrity – MD5 Route Authentication

Authentication – Digital Certificates

Confidentiality – IPSec/IKE/3DES

Virus Detection – McAfee/Norton Antivirus Software

Monitoring Security

Monitoring community visitors for safety assaults, vulnerabilities and weird occasions is important for any safety technique. This evaluation identifies what methods and functions are being employed. The following is an inventory that describes some typical monitoring options. Intrusion detection sensors can be found for monitoring actual time visitors because it arrives at your perimeter. IBM Internet Security Scanner is an glorious vulnerability evaluation testing software that needs to be thought-about in your group. Syslog server messaging is a regular Unix program discovered at many firms that writes safety occasions to a log file for examination. It is vital to have audit trails to document community adjustments and help with isolating safety points. Big firms that make the most of a number of analog dial strains for modems typically make use of dial scanners to find out open strains that may very well be exploited by safety hackers. Facilities safety is typical badge entry to gear and servers that host mission essential knowledge. Badge entry programs document the date time that every particular worker entered the telecom room and left. Cameras typically document what particular actions have been carried out as nicely.

Intrusion Prevention Sensors (IPS)

Cisco markets intrusion prevention sensors (IPS) to enterprise shoppers for enhancing the safety posture of the corporate community. Cisco IPS 4200 collection make the most of sensors at strategic areas on the within and out of doors community defending switches, routers and servers from hackers. IPS sensors will look at community visitors actual time or inline, evaluating packets with pre-outlined signatures. If the sensor detects suspicious habits it’ll ship an alarm, drop the packet and take some evasive motion to counter the assault. The IPS sensor will be deployed inline IPS, IDS the place visitors would not circulation by gadget or a hybrid gadget. Most sensors inside the info heart community can be designated IPS mode with its dynamic safety features thwarting assaults as quickly as they happen. Note that IOS intrusion prevention software program is obtainable at the moment with routers as an possibility.

Vulnerability Assessment Testing (VAST)

IBM Internet Security Scanner (ISS) is a vulnerability evaluation scanner targeted on enterprise prospects for assessing community vulnerabilities from an exterior and inner perspective. The software program runs on brokers and scans numerous community units and servers for identified safety holes and potential vulnerabilities. The course of is comprised of community discovery, knowledge assortment, evaluation and reviews. Data is collected from routers, switches, servers, firewalls, workstations, working programs and community providers. Potential vulnerabilities are verified by non-harmful testing and suggestions made for correcting any safety issues. There is a reporting facility obtainable with the scanner that presents the knowledge findings to firm employees.

Syslog Server Messaging

Cisco IOS has a Unix program known as Syslog that reviews on quite a lot of gadget actions and error circumstances. Most routers and switches generate Syslog messages, that are despatched to a chosen Unix workstation for overview. If your Network Management Console (NMS) is utilizing the Windows platform, there are utilities that enable viewing of log information and sending Syslog information between a Unix and Windows NMS.

Copyright 2006 Shaun Hummel All Rights Reserved

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