Keeping A Network Secure Computer Science Essay

Keeping the web secure is one of the more of import ends for a web decision maker which is including when our users remotely entree the web. The Group Policy Object ( GPO ) in Windows Server 2008 provides a dial to put permissions for user groups and abilities.

This study describes the distribution of web entree policy and constellation files are used to allow or deny users entree web resources across distant connexions. We will first look in more item the hallmark protocol is included in Windows Server 2008. We will besides larn how to cover with distant entree runing system security. We will so come in the configure user entree profiles and inside informations of schemes and plunging. We will besides larn how to configure our waiter to utilize Windows hallmark or RADIUS hallmark.

This study has covered configuring web hallmark, may include but is non limited to: LAN hallmark by utilizing NTLMv2 and Kerberos. , WLAN hallmark by utilizing 802.1x, RAS hallmark by utilizing MS-CHAP, MS-CHAPv2 and EAP, Remote Access Policy, Network Address Translation ( NAT ) , Connection Manager. It is configuring Network Access Protection ( NAP ) . May include but is non limited to: Network bed protection, DHCP enforcement, Default user profiles, VPN enforcement, Configure NAP wellness policies, IPSec enforcement, 802.1x enforcement, and Flexible host isolation. Its configuring firewall scenes, may include but non limited to: entrance and surpassing traffic filtering, Active Directory history integrating, Identify ports and protocols, Windows Firewall vs. Windows Firewall with advanced security, Configure firewall by utilizing group policy, Isolation policy.


Distant Access Security

In the yesteryear, the bulk of distant entree is seldom portion of the company ‘s web. This is excessively hard to implement, pull off excessively difficult, excessively difficult security. It is reasonably easy to derive unauthorised physical entree to our web, but it is considered distant entree even more hard to make so. Recently, security policies, protocols and techniques have been developed to relieve this job.

User Authentication

In the constitution of secure distant entree connexion is one of the first measure, leting the user to do some certificates to the waiter. We can utilize any or all of the hallmark protocol support for Windows Server 2008:

Password Authentication Protocol

The Password Authentication Protocol ( PAP ) is the simplest hallmark protocol. It transmits all hallmark information in clear text with no encoding, which makes it vulnerable to spying if aggressors can set themselves between the modem bank and the distant entree waiter. However, this type of onslaught is improbable in most webs. The security hazard with PAP is mostly overemphasized sing the trouble of puting up a sniffer in between the modems and the distant entree waiter. If an aggressor has the ability to put in a sniffer this deep in the web, we have larger jobs to turn to.

PAP is the most widely supported hallmark protocol, therefore may happen that we need to go forth it enabled.

Microsoft CHAPv2

Microsoft CHAPv2 device ( MS – CHAPv2 ) CHAP protocol by Microsoft as an extension, let the usage of Windows hallmark information. Version 2 Release 1 ratio, which is non supported by the Windows 2008 security. Other runing systems support MS – CHAP version 1.

Extensile Authentication Protocol

Extensile Authentication Protocol ( EAP ) does non supply any hallmark itself. Alternatively, it relies on external third-party hallmark method ; we can be added to the bing waiter. Alternatively of a difficult connexion to any hallmark protocol, client / server can understand negotiate EAP hallmark methods. Required to authenticate a computing machine to verify who is free to inquire a few pieces of information, such that for every individual question. This allows about any usage of hallmark methods, including smart cards, secure entree, such as SecurID items, such as the S / key, or an ordinary user name / watchword system, a erstwhile watchword system.

Each hallmark scheme supported in EAP is called an EAP type. Each EAP type is as a plug-in faculty. Windows Server 2008 can back up any type of EAP ranked foremost in the Routing and Remote Access Service ( RRAS ) waiter can utilize any type of EAP hallmark, the faculty if we are allowed to hold jobs with the client for the faculty.

Windows Server 2008 comes with EAP-Transport Level Security ( TLS ) . ) . This EAP type can be used to verify the public key certification. TLS is similar to the familiar Secure Sockets Layer ( SSL ) protocol used Web browser. When EAP_TLS is turned on, the client and server direct TLS-encrypted message back and Forth EAP – Thallium is the most powerful hallmark method, we can utilize ; as a fillip, it supports smart cards. However, EAP – TLS needs of our RRAS waiter is portion of Windows Server 2008 sphere.

The radius is another EAP hallmark method with the Window Server 2008 in. Radius EAP type is false to any incoming message to the Remote Authentication Dial in User Service ( RADIUS ) hallmark waiter.


NTLMv2 aid system for Windows NT4 or earlier versions of the enfranchisement procedure and between any two computing machines running these minutess allow the old system. Networks use NTLMv2 is called mixed-mode, which is the default puting in Windows Server 2008 sphere.


Active Directory sphere hallmark is done by utilizing the Kerberos hallmark protocol. By default, all computing machines joined to a Windows Server 2008 sphere to utilize the Kerberos hallmark protocol Allow Kerberos individual sign-on to a sphere or trusted sphere web resources. Administrators have the ability to control, through the history of the Kerberos security policy set some parametric quantities.


In IEEE 802.1X a enfranchisement criterion called Wireless.802.1X authenticated wireless web to wired Ethernet or radio allows 802.11 webs. IEEE 802.1X criterion EAP hallmark procedure used in the exchange of information.

Connection Security

We can utilize some extra characteristics for us to supply distant entree client connection-level security:

Callback Control Protocol ( CBCP ) to let our RRAS waiter or client in audience with the other terminal of the recall. When the CBCP is enabled, the client or waiter can inquire the waiter at the other terminal of the call by the client or reserve figure stored on the waiter back to the figures provided by the client.

We can plan the RRAS waiter to accept or reject the company ID or automatic figure designation ( ANI ) information transportation Phone Company ‘s phone. For illustration, we can bespeak major RRAS waiter merely accepts linear line from our place phone. This means that we can non name the waiter, we are on the route, and it besides prevents aliens ‘ waiter.

We can stipulate different types and degrees of encoding to protect our connexion is blocked or tampered with.

Access Control

Addition to connection-level steps, we can utilize it to speak to the waiter other than the forbidden calls, we can curtail which users can remotely link in a assortment of ways:

We can enable or disenable user histories from a individual distant entree. This is the same limited control which have in Windows NT, but it is merely the beginning for the Windows Server 2008.

We can utilize the web entree policies to command whether users can entree.

Like Group Policy, web entree policies give us a simple manner to use a consistent set of policies for the user group. However, the policy mechanism is a small different: we create a regulation, included or excluded in the policy of our user demands.

Unlike group policy, web entree policy applies merely to Windows 2000 native manner, Windows Server 2003 and Windows Server 2008 sphere functional degree ( that is, each of these countries, including Windows NT domain accountant does non be ) .This means that we may non take to utilize until our Windows 2000 and Windows Server 2003 and Windows Server 2008 to deploy web entree scheme is to travel farther. In the following subdivision, we will larn how to configure user entree control.

Configuring User Access

In the old subdivision, we set the waiter to accept incoming calls. Now is the clip to make up one’s mind who can really utilize the distant entree service. We can make this in two ways:

By puting up distant entree profiles on single histories

By making and pull offing web entree policies that apply to groups of users

The differentiation is elusive but really of import, because we direction and application profiles in different topographic points and policies.

Puting up User Profiles

Windows Server 2008 stored in the user ‘s history information for each batch. In general, this information is known as the history ‘s constellation file, which is normally stored in Active Directory. Configuration file in the user scenes are available through some of these one of the user direction unit:

If our RRAS waiter is portion of an Active Directory sphere, the user profile scenes are in the Active Directory Users and Computer snap-in.

If our RRAS waiter is non portion of an Active Directory sphere, the user profile scenes are in the Local Users and Group snap-in.

In both instances, the constellation file of the interesting portion is the dial-up user ‘s Properties duologue box check ( see Figure 1.1 ) . This check has a figure of controls that regulate how the user

Network Access Permission control group

The first and likely most familiar in this check command the web entree control group. These options control whether the user has dial-in permissions. They are similar to the control of us may retrieve from the Windows NT User Manager, nevertheless, Windows Server 2008 ‘s new characteristics: In add-on to explicitly let or deny entree, we can entree through the web entree policy control.

Verify Caller-ID controls

RRAS can verify the user ‘s company ID information, and utilize the consequences to let or deny entree. Caller ID when we check that box, and come in a phone figure in the field, we tell RRAS the phone to anyone who refused to supply the user name and watchword, but the company ID information does non fit our input. This means that users can merely name a phone figure.

Callback Option control group

The Callback Option control group gives us three picks for modulating recall:

No Callback ( the default puting ) means the waiter will ne’er honour recall petitions from this history.

Set By Caller allows the naming system to stipulate a figure honor recall petitions from this history.

Always Callback To let us to come in a figure that the waiter will name back no affair from where the client is really naming. This option is less flexible but more secure than the Set By Caller option.

Delegate A Static IP Address controls

If we want this user to ever acquire the same inactive IP reference, we can take a inactive IP reference allotment agreements for cheque box, and enter the IP reference. This allows us to put the non-dynamic DNS records for single users, to guarantee that their machines will ever hold a valid DNS entry. On the other manus, this can be easier than the dynamic DNS, DHCP combination, we can put in and utilize, alternatively of publishing mistakes.

Apply Static Routes cheque box

In a normal LAN, we do non make anything particular clients, enabling them to route packages, merely configure a default gateway to them, the remainder of the gateway intervention. For dial-up connexion, but we may desire to specify a inactive routing tabular array so that the distant client to the host on the web, otherwise, no package is sent to the gateways. Depending on the distant entree waiter, but the client may be able to utilize a local device Address Resolution Protocol ( ARP ) of the. If we want to specify a inactive path on the client scenes, we will hold to make it manually. If we want to delegate a inactive path on the waiter, inactive routing to use look into box, and so utilize the inactive path button, attention deficit disorder and take paths as needed.

Using Network Access Policies

Windows Server 2008 includes support for two extra constellation systems:

Network entree policies ( which used to be called distant entree policy )

Remote entree profiles

Policies determine who can and can non link ; our definition of the conditions of the regulations, systems appraisal, to see if a peculiar user can link

We can either pure Windows Server 2008 sphere, some of the policies ; each policy must hold an associated personal informations.

We have to pull off distant entree logging and policy web entree policy booklet in the RRAS snap-in. Our policy conditions, including choice from the list. When a company connects, the policy ‘s conditions are evaluated, one by one, to see whether the company gets in. All the conditions in the policy must fit for the user to derive entree. If there are multiple schemes, they evaluate the order us specify.

Network Access Policy Attributes

Authentication Type – Specifies the hallmark methods required to fit this policy.

Allowed EAP Types – Specifies the EAP types required for client computing machine hallmark method constellation to fit this policy.

Called-Station-Id – Specifies the phone figure of the distant entree port called by the company.

Calling-Station-Id – Specifies the company ‘s phone figure.

Client-Friendly-Name – Specifies the name of the RADIUS waiter that ‘s trying to formalize the connexion.

Client-IP-Address ( IPv4 and IPv6 ) – Specifies the IP reference of the RADIUS waiter that ‘s trying to formalize the connexion.

Client-Vendor – Specifies the seller of distant entree waiter that originally accepted the connexion. This is used to put different policies for different hardware.

Day-And-Time Restrictions – Specifies the weekdays and times when connexion efforts are accepted or rejected.

Framed-Protocol – Specifies the protocol to be used for bordering incoming packages ( for illustration, PPP, SLIP, and so on ) .

HCAP ( Host Credential Authorization Protocol ) User Groups – Used for communications between NPS and some third-party web entree serves ( NAS ) .

Location Groups – Specifies the HCAP location groups required to fit this policy. This is used for communications between HCAP and some third-party web entree waiters ( NAS ) .

MS-RAS Vendor – Specifies the seller designation figure of the web entree waiter ( NAS ) that is bespeaking hallmark.

NAS-Identifier – Specifies the friendly name of the distant entree waiter that originally accepted the connexion.

NAS-IP-Address ( IPv4 and IPv6 ) – Specifies the IP reference of the distant entree waiter that originally accepted the connexion.

NAS-Port-Type – Specifies the physical connexion ( for illustration, ISDN, POTS ) used by the company.

Service-Type – Specifies Framed or Async ( for PPP ) or login ( Telnet ) .

Tunnel-Type – Specifies which burrowing protocol should be used ( L2TP or PPTP ) .

Windows-Groups – Specifies which Windows groups are allowed entree.

Using Properties with Authentication

Be careful when utilizing properties for web entree policies. We can efficaciously forestall the hallmark, if we specify the belongings is non right, or if a individual ‘s sudden alteration in the value of the belongings.

For illustration, if we use the NAS port type property to stipulate the line type that a user can verify the alterations and NAS port type, the user can non be verified.

Different web entree waiter vendor NAS-Port-Type defined different. A provider can be called a device called the model of another seller ‘s equipment, asynchronous even though both describe a typical dial-up line connected to a modem. In add-on, the value of certain belongingss may alter between versions of the package seller. Imagine 1000s of updated microcode for the modem to happen the name of a belongings has changed, and now no 1 can dial it!

Using Remote Access Profiles

Distant entree policy constellation file is portion of web entree. Configuration file determines the constitution and completion of the call. Each policy has an associated profile ; constellation file scenes determine what will be applied to the connexion line with the policy of a status.

For security grounds, is normally a good thought to curtail entree to the web decision maker history? In peculiar, as a adviser, we normally tell clients are limited to the decision maker history for distant entree ; this manner, from a dial-up reduces the possible hazard of via media.

The Constraints Tab

Constrained to put the label, we think of when we consider the most dial-in entree control. This control allows us to set how long the connexion can be idle before it gets dropped, how long can be achieved, the day of the month and clip to set up a connexion, and the medium can be used for dial-up ports and connexions.

Authentication Link

In the Authentication Methods window glass, we can stipulate the hallmark method in this specific policy allowed. Please note that these scenes, like other policy scenes, will be utile merely when the waiter scenes lucifer. For illustration, if EAP hallmark is turned off in the waiter ‘s Properties duologue box, the hallmark method configured in the file window glass of the Properties duologue box will non hold any consequence on.

Settings Tab

IP Settings window glass

The IP Setting window glass gives us control over the IP-related scenes associated with an incoming call.

Multilink And Bandwidth Allocation Protocol ( BAP ) window glass

Mechanism for the constellation file gives a control server how to manage multiple demands degree. Normally this scene is configured so that server-specific scenes take precedency, but we can overrule them.

Bandwidth Allocation Protocol ( BAP ) Settings group

Bandwidth Allocation Protocol ( BAP ) set the control group provides a manner for us to command the call occurred during the usage of multi-link bandwidth is below a certain threshold. Why, for illustration, three parallel lines tied to supplying 168Kbps bandwidth connexions merely 56Kbps of? We can set the capacity and clip threshold, by default, a multi-line call to drop the bandwidth used by each down to less than 50 per centum of the available bandwidth and keep two proceedingss. Please look into the nexus for dynamic multi-BAP petition, refused to allow client ‘s phone does non back up BAP, which is a simple manner to guarantee that no client ‘s multi-link bandwidth pig.

Encoding check

The Encryption check controls which type of encoding for distant users to be able to entree. The undermentioned wireless buttons are on the Encryption check:

Basic Encryption ( MPPE 40-Bit ) means individual Data Encryption Standard ( DES ) for IPSec or 40-bit Microsoft Point-to-Point Encryption ( MPPE ) for Point-to-Point Tunneling Protocol ( PPTP ) .

Strong Encryption ( MPPE 56 Bit ) means 56-bit encoding ( individual DES for IPSec ; 56-bit MPPE for PPTP ) .

Strongest Encoding ( MPPE128 Bit ) means ternary DES for IPSec or 128-bit MPPE for PPTP connexions.

No Encryption allows users to link utilizing no encoding at all. Unless this button is selected, a distant connexion must be encrypted, or it will be rejected.

Puting Up a VPN Network Access Policy

Early on in this study, we learned how to utilize Windows Server 2008 sphere web entree policy mechanism. Now clip to use what we have learned a practical private web ( VPN ) . Remember that, we have two ways to command which specific users can entree the distant entree waiter:

We can allow and deny dial-up permission to single users in each user ‘s Properties duologue box.

We can make a web entree policy that embodies whatever limitations we want to enforce.

Facts have proved that we can make the same thing VPN connexion, but there are some extra things to see.

Allowing and Denying Per-User Access

To allow or deny VPN entree to single users, all have to make is do the appropriate alteration on the Dial-In check of each user ‘s Properties duologue box. Although this is the easiest method to understand, it gets boring rapidly if need to alter VPN permissions for more than a few users. Furthermore, this method offers no manner to separate between dial-in and VPN permissions.

Making a Network Access Policy for VPNs

We may happen it helps to make a web entree policy enforcement authorization, we want the terminal user has. We can make this in many ways the consequence of which 1 we use will depend on our overall usage of web entree policy.

The easiest manner is to make a policy that allows all users to utilize the VPN. Back in this study, we learn how to make a web entree policy, and stipulate their scenes ; one thing, we may hold noticed, there is a NAS port type properties, we can utilize the policy conditions. The belongings is to construct a policy to let or deny distant entree via VPN the basis, because we use it to accept or reject the connexion, in a peculiar type of VPN connexion to get. For best consequences, we will utilize in concurrence with the NAS port type property type property tunnel.

If we do non desire everybody to give VPN entree, we can polish some of the procedure of alteration. First of wholly, we might desire to travel the VPN policy to the top of the list. We can make an Active Directory group and set our VPN users. Then, we can make a scheme, with two-plus-one status, use the Windows group property to stipulate the new group the conditions outlined. We can besides utilize this procedure, so that everyone VPN dial-up entree for little groups map and modesty.

Connection Manager

To assist decision makers make and pull off distant entree connexions, including Microsoft Windows Server 2008 bundle constituents are called Connection Manager. Connection Manager is non installed by default. We can put in utilizing the Server Manager ; add the function of Connection Manager, and Internet entree services.

Connection Manager allows decision makers to make a distant entree connexion as service constellation file. These profiles, and so displayed in the client computing machine ‘s web connexion. We can utilize the web connexion to the client to link to the VPN or remote webs.

Configuring Security

When we configure a distant entree security, we must see several facets, the most cardinal constellation, including the type of hallmark and encoding will accept client requests the waiter to utilize. We will look at each of these in the undermentioned subdivisions.

Controling Server Security

The waiter ‘s Properties dialog box Security check allows stipulating the hallmark and accounting methods RRAS uses. We can utilize the Authentication supplier drop-down list one of two hallmark suppliers.

RADIUS Authentication Settings

When we select the RADIUS Authentication option from the Authentication Provider drop-down bill of fare, we are enabling a RADIUS client that passes hallmark responsibilities to a RADIUS waiter. This communicating is sent through UDP port 1645 or 1812, depending on the version we are utilizing RADIUS.

Windows Authentication Settings

Choice Windows Authentication from the Authentication drop-down bill of fare provides picks, if we want to authenticate the local computing machine remote entree users. To configure the waiter, stating it the hallmark method, we want to utilize it, click the button to the hallmark method, it shows Authentication Methods duologue box. If we are in forepart of the hallmark protocol, a list of chapters in the study, we will happen that everyone has the appropriate cheque box here: EAP clip, MS – CHAPv2, CHAP and PAP hallmark. We can besides open a checking allows entree to remote systems without connexion, without hallmark box, but non recommended because it allows anyone to entree and usage of our waiter ( and hence by our web enlargement ) .

There is really a set of particular demands to utilize CHAP, because it needs entree to each user ‘s encrypted watchword. Windows Server 2008 is by and large non in a format that cat can utilize to hive away user watchwords.

Configuring Network Access Protection

Another manner we can hold is to allow users procure entree to the individuality of the client computing machine based resources. The new security solution called Network Access Protection ( NAP ) .Determined by the client needs ; web decision makers can now find the web utilizing NAP entree farinaceous degree. National action plan besides allows decision makers to find on the footing of client entree policy conformity and corporate administration.

Network bed protection

Network bed protection is the ability to procure communications at the Network bed of OSI theoretical account.

DHCP enforcement

If the computing machine ‘s IPv4 webs want to acquire limitless entree, the computing machine must run into the corporate administration policies. DHCP force hallmark before allowing entree to limitless computing machine criterions. If the computing machine does non run into, the computing machine receives the IPv4 reference of a really limited web entree and the default user profile.

VPN enforcement

VPN enforcement works a batch like DHCP enforcement except that VPN enforcement verifies the complaisance of the system before the VPN connexion is given full entree to the web.

IPSec enforcement

The execution of IPSec will let computing machines and other computing machine communications, every bit long as the computing machine ‘s IPSec criterion. We have the ability to configure the computing machine system compatibility between the secure communicating demands. We can configure the IP reference or TCP / UDP port figure of IPSec-based communicating.

802.1X enforcement

For a computing machine system with an 802.1x web connexion ( Ethernet or wireless 802.11 entree point ) unlimited entree, the computing machine system must 802.1X standard.802.1X enforcement verify the connexion system is 8021X connexion criterion. Defiant computing machines will obtain merely limited entree to web connexions.

Flexible host isolation

Flexible host isolation allows the computing machine waiter and sphere isolation to assist it possible to plan a security bed between computing machines or web. Even if the hacker can entree our web utilizing the authorized user name and watchword, waiter and sphere isolation to halt the onslaught, because the computing machine is the computing machine does non acknowledge the sphere.

Configuring Firewall Options

A firewall is a package or hardware device to look into has been received from the external ( Internet ) or an external web, and from information to make up one’s mind whether to accept or reject the package information. Different on the firewall, we may hold the ability to look into all Active Directory, remote users, remote users authorized to verify the sphere history. This procedure is called Active Directory history integrating. Microsoft Windows Server 2008 has a constitutional firewall. The followers are some of the constellation options included the Windows Firewall Settings duologue box:

Windows Firewall Settings-General check

On the Windows Firewall Settings duologue box ‘s General check, we have the ability to turn the firewall on and off. When we open the firewall, we besides have the ability to barricade all entrance traffic. This will halt all traffic on the entree waiter.

Windows Firewall Settings-Exceptions check

In the Exceptions check allows to use for their exclusion from the firewall scenes. If enable the firewall, this check gives the undermentioned options:

We can let certain applications to go on to entree the firewall.

We besides have the ability to add plans to the exclusions.

We besides have the ability to make traffic filtering by ports and protocols

Finally, we have the ability to see the belongingss of any of the applications for exclude.

Traffic filtrating

When the set of Microsoft Windows Server 2008 firewall, decision makers have the ability to filtrate traffic to the port and protocol.

Windows Firewall Settings-Advanced check

Windows Firewall Settings duologue box Advanced check allows to choose the web connexion and want to enable the firewall. For illustration, if we have multiple web cards, we can take which connexion, the firewall scenes are applied.

Firewall With Advanced Security

Windows Server 2008 firewall in the control panel further than the normal firewall scenes. An MMC snap-in called Windows Firewall with Advanced Security to barricade all entrance and surpassing connexions of its constellation.

One of the chief advantages of utilizing the Advanced Security snap-in firewall is the ability to utilize Group Policy scenes in the firewall constellation on the distant computing machine. Another advantage is the ability to utilize the MMC to put firewall security utilizing IPSec. Firewall with Advanced Security snap-in allows decision makers to put a more in-depth Microsoft Active Directory users and groups, beginning and finish Internet Protocol ( IP ) reference, IP port figure, ICMP scenes, IPSec scenes, the specific regulations of interface types and services.


In this study, we have learned about distant entree and hallmark. We have learned that the user hallmark protocols included with Windows Server 2008 are PAP, CHAP, MS-CHAPv2, Kerberos, NTLMv2, 802.1X, and EAP. We besides learned that the Dial-In check of a user ‘s Properties duologue box has a figure of interesting controls that regulate how the user history may be used for dial-in entree. We covered how to utilize web entree policies to find who may and may non link, every bit good as the procedure for specifying regulations with conditions that the system evaluates to see whether a peculiar user can link. We have learned about the Windows Firewall option and the Windows Firewall With Advanced Security MMC. We discussed the Network Access Protection ( NAP ) options and characteristics. In add-on, you learned how to utilize web entree profiles that contain scenes that determine what happens during call apparatus and completion. Finally, you learned how to configure which accounting and hallmark methods RRAS usage.