DirectAccess clients establish IPsec tunnels for the IPv6 DirectAccess traffic to the Forefront UAG DirectAccess server, which acts as a gateway to the intranet.
By default, DirectAccess clients create two tunnels to the Forefront UAG DirectAccess server.
- The infrastructure tunnel— Provides
access to intranet Domain Name System (DNS) servers, Active
Directory Domain Services (AD DS) domain controllers, and other
infrastructure management servers.
- The intranet tunnel— provides access
to intranet resources such as Web sites, file shares, and other
application servers, and opens once the client logs in.
You can configure Forefront UAG DirectAccess to only use the infrastructure tunnel.
You can choose one of the following deployment models:
- Full intranet access—The DirectAccess
client establishes both the infrastructure and intranet tunnels and
therefore has access to all resources on the intranet.
- Enable Remote management of DirectAccess
clients only—Only establishes the infrastructure tunnel between
the DirectAccess client and the Forefront UAG DirectAccess server.
The DirectAccess client computer therefore only has access to the
infrastructure and management servers configured in the Forefront
UAG DirectAccess Configuration Wizard.
To choose a deployment model
-
In the Forefront UAG Management console, click DirectAccess to start the Forefront UAG DirectAccess Configuration Wizard.
-
From the Forefront UAG DirectAccess Configuration Wizard, under Step 1, in Clients and GPOs, click Edit.
-
Select the deployment model you wish to use.
To enable Full intranet access, click Allow DirectAccess clients to connect to internal networks ….
To enable access to management servers only, click Enable Remote management of DirectAccess clients only.
Note: If you select the Enable Remote management of DirectAccess clients only deployment model: - Allow only services is automatically
selected, and limits access to infrastructure servers to services
with computer-account credentials running on the client computer
(this is the default selection).
- To enable user authentication with management
servers, deselect Allow only services. This would be
necessary in organizations that require a user to authenticate with
management servers.
- Allow only services is automatically
selected, and limits access to infrastructure servers to services
with computer-account credentials running on the client computer
(this is the default selection).
-
Click Next. The Client Domains page of the Forefront UAG DirectAccess Configuration Wizard opens.
Note the following when deploying Forefront UAG DirectAccess for remote management only:
To choose a deployment model
-
In the Forefront UAG Management console, click DirectAccess to start the Forefront UAG DirectAccess Configuration Wizard.
-
From the Forefront UAG DirectAccess Configuration Wizard, under Step 1, in Clients and GPOs, click Edit.
-
Select the deployment model you wish to use.
To enable Full intranet access, click Allow DirectAccess clients to connect to internal networks ….
To enable access to management servers only, click Enable Remote management of DirectAccess clients only.
Note: If you select the Enable Remote management of DirectAccess clients only deployment model: - Allow only services is automatically
selected, and limits access to infrastructure servers to services
with computer-account credentials running on the client computer
(this is the default selection).
- To enable user authentication with management
servers, deselect Allow only services. This would be
necessary in organizations that require a user to authenticate with
management servers.
- Allow only services is automatically
selected, and limits access to infrastructure servers to services
with computer-account credentials running on the client computer
(this is the default selection).
-
Click Next. The Client Domains page of the Forefront UAG DirectAccess Configuration Wizard opens.
Merging local rules
When deploying Forefront UAG DirectAccess for remote management only, clients can potentially access an intranet server via DirectAccess by creating and merging local IPsec rules with corporate policy rules.
This can occur because by default users in the local administrators group can create connection security rules on the local computer using Windows Firewall with Advanced Security. These local rules can be merged with corporate rules and applied to the computer. This can only occur under the following circumstances:
- The user must belong to the local administrators group on the
DirectAccess client computer in order to create transport mode
IPsec rules (and enable rule merging if it is disabled by group
policy).
- The user must have local administrator permissions on an
internal server in order to create transport mode IPsec rules (and
enable rule merging if it is disabled by group policy).
- In order to gain access to the internal server the user must
have configured the IPsec rules on the server before connecting via
DirectAccess. The user cannot gain access to internal servers that
do not have the IPsec rules configured.
To mitigate this potential behavior the following options are available:
- Ensure that your corporate policy states that
users should not create local connection security rules.
- When DirectAccess is deployed for remote
management only, do not provide users with local administrator
privileges on DirectAccess client computers.
- Disable rule merging in each domain, as
follows:
- Open the Group Policy Management console.
- Select the policy you want to edit. You can use an existing
policy such as the default domain policy and apply it on the entire
domain, or create a dedicated policy and apply it to DirectAccess
client computers only.
- In the policy settings, under Security Settings,
right-click Windows Firewall with Advanced Security,
and then click Properties.
- There are two methods for configuring and applying the
setting:
- If you are applying the policy to the entire domain, on each
profile (domain, private, and public) set Apply local
connection security rules to No.
- If you are using a dedicated policy to apply on DirectAccess
client computers only, on private and public profiles, set Apply
local connection security rules to No.
- If you are applying the policy to the entire domain, on each
profile (domain, private, and public) set Apply local
connection security rules to No.
- Open the Group Policy Management console.
Note that local administrators can still manually modify the registry entry that disables the merging of local IPsec policy. If this occurs the administrator can create local rules until the modification is next overwritten with group policy.