Policy Manager
Concepts


This topic explains some of the concepts you'll need to understand in order to make the most effective use of Policy Manager.

Information on:

Policy

In Policy Manager, network access policies are called Roles. See Role, below, for a description.

Role

What is a Role

In Policy Manager, a role is a set of network access services that can be applied at various access points in a policy-enabled network. A port takes on a user's role when the user authenticates. Roles are usually named for a type of user such as Student or Engineering. Often, role names will match the NT Domain or NDS (Network Directory Server) naming conventions that already exist in the organization. A role can contain any number of services in Policy Manager.

A role may also contain default access control (VLAN) and/or class of service (priority) characteristics that will be applied to traffic not identified specifically by the set of access services contained in the role. The set of services included in a role, along with any access control or class of service defaults, determine how all network traffic will be handled at any network access point configured to use that role.

Default Role

Once you have created a role, you can assign it as the default role for a port (see Assigning Default Roles to Ports). The default role becomes the current role for the user on a port if:
  1. unauthenticated behavior is set to "Default Role," and
  2. either of these cases is true:
If authentication is disabled on a port, the default role is the only way policy can be assigned to an end user. You can view the ports for which the role is the default role on the role Ports tab, and use the View/Edit Ports button to make default role changes.

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Service

Policy Manager services are sets of rules that define how network traffic for a particular network service or application should be handled by a network access device. A service might consist of only one rule governing, for example, email priority, or it might consist of a complex set of rules combining class of service, filtering, rate limiting, and access control (VLAN) assignment. A service can be included in any number of roles in Policy Manager.

As an example, you might create a service called "High Priority Internet Web Access" that contains priority classification rules for traffic directed toward each of your organization's Internet proxy servers. This service would likely contain one traffic classification rule for each of your Internet proxy servers.

There are two types of services in Policy Manager:

Policy Manager services provide a common language that network engineers, information technology administrators, and business managers understand. See How to Create a Service for more information.

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Rule

What is a Rule

In Policy Manager, a rule defines one element of how traffic for a particular network service or application will be handled by a network access device. For example, you might create a rule that assigns a certain priority to all email traffic, by adding an 802.1p, ToS, or DiffServ value to all SMTP traffic. In Policy Manager, a rule can be included in any number of services, and you can select the types of devices to which the rule applies.

See Traffic Classification Rules for a detailed explanation of rules.

Disabling Rules

In Policy Manager, you can elect to disable a rule during or after its creation. If you disable a rule, it is temporarily unavailable for use by the current service, but it can still be copied to other services and enabled, or re-enabled at another time for the current service. Disabling a rule is a way to temporarily remove a rule from your service without having to delete and recreate it.

Conflict Checking

As your Policy Manager database grows, the potential for conflicts between new and existing rules in a service or role increases. For example, two rules might have the same traffic descriptor but forward traffic to different VLANs, or have different priorities. If the two rules are applied to the same service, or to the same role via two different services, unpredictable and undesired behavior could result.

Policy Manager ensures that this does not occur by checking rule traffic descriptions and action values, providing a message if conflicts are found, and writing the conflict information to the Event Log. Conflicts are checked at the following points:

If a rule is disabled, conflicts between that rule and others are ignored.

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Authentication

Authentication is the process by which end users identify themselves to the network and are given customized access capabilities based on the role they serve in the organization.

In the past, the IP address has been a means of identifying users on a network. But the mobility of today's workforce and the dynamic nature of IP address assignment has rendered the IP address ineffective as an indicator of the user's identity. Authentication via the user's login has become the most viable option for discovering a user's identity, and provides a mechanism by which policy may be enforced, as well.

Authentication Types

Policy Manager offers the following types of authentication. Some devices support multiple authentication types and multiple users (Multi-User Authentication) per port, while others are restricted to only one or two authentication types and single users per port (Single User Authentication). Refer to the Policy Manager Release Notes for information on the authentication types supported by each device type.
  NOTE: Single User 802.1X+MAC Authentication. On Matrix E1 and Matrix E6/E7 devices, if both 802.1X and MAC authentication are enabled on a device, it is possible for the device to receive a start or response 802.1X packet while a MAC authentication is in progress. If this happens, the device immediately terminates the MAC authentication, and the 802.1X authentication proceeds to completion. Regardless of the success of the 802.1X login attempt, no new MAC authentication logins may occur on the port until 1) the link is toggled; 2) the user executes an 802.1X logout; or 3) the 802.1X session is terminated administratively.

RADIUS Authentication

Policy Manager uses a RADIUS server and an authentication-enabled switch to allow the active policy (or role) on a port to be dynamically assigned, based on the user's login. Funk Software, Inc.'s RADIUSTM (Remote Authentication Dial In User Service) is an authentication solution that has been tested at Enterasys. It exchanges information between a RADIUS client (a device that provides network access to users) and a RADIUS server (a device that contains authentication information for these users).

How Authentication Works

If authentication is enabled on a network port, a user connected through that port may not be allowed to access network resources unless the user's user name and password are authenticated by the RADIUS authentication server. The unauthenticated port may be configured with some default access permissions, through the use of a default role, or the port may be configured to deny all network access until a user authenticates.

When a user logs in, the RADIUS server is contacted to determine whether or not a policy profile (role) exists for the user in its database. If a role exists, the user is allowed to access the network, and that user's role becomes the current role for the port. If authorization fails, the user is not allowed on the network, and the port assumes the default role for the port. (Only one default role is allowed per port.)  Once a role is assigned to a port, the port's current role takes precedence over its default role, and the only way it can be replaced with another role is via authentication, or if the user logs out.

There are some devices within an IT system that may not be configured for authentication. These include printers, FAX machines, and legacy devices such as software-based routers and shared hubs. You can configure default network behavior for these devices in Policy Manager by assigning default roles to the desired network ports or port groups. (See Assigning Default Roles to Ports for more information.)

Port Authentication States

When deploying an Enterasys authentication-enabled network, there are three primary port authentication states that can exist: You can control the state of a port with regard to authentication by defining its port mode in Policy Manager.

Port Mode

Port mode defines whether or not a user is required to authenticate on a port, and how unauthenticated traffic will be handled. It is a combination of Authentication Behavior (whether or not authentication is enabled on the port), and Unauthenticated Behavior (whether unauthenticated traffic will be assigned the port's default role or discarded). These two settings can be combined to create four possible port modes. It is important to plan in advance the port mode for the ports in your network before implementing authentication in your policy-enabled network. You can configure port mode in the Port Mode window in the Port Configuration Wizard, or in the Authentication Configuration tab for the port. In order for the port mode settings to take effect, authentication must be configured and enabled on the device.

Configuring Authentication in Policy Manager

In Policy Manager you can configure and enable authentication on your devices using the Device Configuration Wizard, or the Authentication tab for the device (see How to Configure Devices). You can configure authentication settings for your ports using the Port Configuration Wizard, or the Authentication Configuration tab for the port (see How to Configure Ports). Before any authentication settings for ports or port groups will take effect, you need to configure and enable authentication on the devices.

You can view login session information for the ports on a selected device on the device's Port Usage Tab, and for a selected port on the port's Port Usage Tab.

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Packet Tagging

Packet tagging in a Policy Manager environment occurs as follows:

Tagged packets and ingress filtering are processed first. Then, VLAN ID and priority are determined. The set of classification rules that are active on a port includes statically created rules that specify the ingress port on their port list, as well as any rules established as a result of a role being applied on that port. If the port has no active role and thus no default access control (VLAN) or class of service (priority), untagged packets that do not match any classification rules are assigned a VLAN and priority from the 802.1Q and 802.1p defaults for the ingress port.

For a graphical illustration of the packet tagging process in a Policy Manager scenario, see the Packet Flow Diagram. The packet passes through the decision-making process illustrated in the graphic twice -- once for VLAN tagging and once for priority tagging.

  NOTE: Policy Manager offers a Drop VLAN Tagged Frames feature which, if enabled, drops any VLAN tagged packet arriving at a port. This provides extra security in that it prevents users from, for example, coming in with a card capable of VLAN tagging and attempting to access the network. It is recommended that you enable the Drop VLAN Tagged Frames feature when you set a default role on a port or when you enable authentication on a port, because these things indicate that the port is a user port that should not be transmitting tagged packets. See Drop VLAN Tagged Frames for more information.

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VLAN to Role Mapping

VLAN to Role mapping lets you assign a role to an end user based on a VLAN ID. There are two kinds of VLAN to Role Mapping: Authentication-Based and Tagged Packet.
  NOTE: Tagged Packet VLAN to Role Mapping requires that the TCI Overwrite attribute be enabled. TCI Overwrite allows the VLAN or class of service tag in a received packet to be overwritten by the VLAN (access control) and class of service characteristics defined in the mapped role. You can enable TCI Overwrite on a per-port basis in the port's General tab, or for an individual role in the role's General tab.

To configure VLAN to Role Mapping in Policy Manager, use the role's Mappings tab and/or the VLAN's General tab. For Authentication-Based VLAN to Role Mapping, you must enable RFC 3580 VLAN Authorization on the device using the device Authentication tab. In addition, VLAN IDs must be configured on the RADIUS server for each user authorized to access the network. If a user does not have a configured VLAN ID, the default role (if there is one) or the 802.1Q PVID for the ingress port is assigned. For more information on configuring VLAN ID attributes on the RADIUS server, refer to your device firmware documentation, RFC 3580, and your RADIUS server documentation.

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Dynamic Egress

In Policy Manager, you can control whether or not Dynamic Egress is enabled for a VLAN by checking or unchecking the box in the Dynamic Egress area on the Create VLAN window or on the General tab for the VLAN. The default setting for Dynamic Egress is enabled.

When Dynamic Egress is enabled for a VLAN, any time a device tags a packet with that VLAN ID, the ingress port is automatically added to the VLAN's egress list, enabling the reply packet to be forwarded back to the source. This means that you do not need to add the ingress port to the VLAN's egress list manually. (See Example 1, below.)

Dynamic Egress affects only the egress lists for the source and destination ingress ports. However, GVRP (GARP VLAN Registration Protocol), which automatically adds the interswitch ingress ports to the egress lists of VLANs, is enabled by default in Policy Manager the first time you enforce a Dynamic Egress VLAN. (See Example 2, below.)

  NOTE: If you do not want GVRP enabled on your network, you can disable it by selecting the Policy Manager Edit > GVRP Disabled menu option. If necessary, you can then manually configure the interswitch ports to do what GVRP does automatically, using NetSight Element Manager or local management to set up your interswitch links as Q trunks. The trunk ports will be automatically added to the egress lists of all the VLANs at the time of trunk configuration.

If GVRP is already enabled on your network and you enforce, the GVRP status of ports on which you have disabled GVRP will not change.

When you disable Dynamic Egress for a VLAN, the VLAN effectively becomes a discard VLAN. Since the destination port is not added to the egress list of the VLAN, the device discards the traffic. If you want a VLAN to act as a discard VLAN, disable Dynamic Egress for that VLAN. (See Example 3, below.)

If an endstation is talking to a "silent" endstation which does not send responses, like a printer, you will need to add the silent endstation's ingress port to the VLAN's egress list manually with a tool like NetSight Switch Manager, NetSight Element Manager, or local management. Dynamic Egress and GVRP take care of adding the other ingress ports to the VLAN's egress list. (See Example 4, below.)

  CAUTION: If no packets are tagged with the applicable VLAN on a port within five minutes, Dynamic Egress list entries will time out. The result is that an endstation will appear "silent" if the VLAN has not been used within that time period. For example, if there is a "telnet" rule and two users (A and B) are on ports whose role includes a service containing the "telnet" rule, if User B has not utilized the "telnet" rule within the five minute time frame, User A will not be able to telnet to User B. For this reason, the best application of Dynamic Egress is for containing undirected traffic on "chatty" clients which utilize, for example, IPX, NetBIOS, AppleTalk, and/or broadcast/multicast protocols such as routing protocols.


Example 1: Dynamic Egress Enabled

In this example, Dynamic Egress is enabled for VLAN 5. When source endstation A is tagged with VLAN 5, Dynamic Egress places A's ingress port (1) on VLAN 5's egress list. When destination endstation B's traffic is tagged with VLAN 5, Dynamic Egress places B's ingress port (2) on VLAN 5's egress list. The device can then forward traffic to both endstations.

Example 2: Dynamic Egress + GVRP

In this example, Dynamic Egress is enabled for VLAN 5, and the destination endstation, B, is on a different device from the source endstation, A. When A is tagged with VLAN 5, Dynamic Egress places A's ingress port (1) on VLAN 5's egress list. GVRP then places interswitch ingress ports (2) and (3) on VLAN 5's egress list. When B's traffic is tagged with VLAN 5, Dynamic Egress places B's ingress port (4) on VLAN 5's egress list. GVRP then places interswitch ingress ports (5) and (6) on VLAN 5's egress list. The devices can then forward traffic to both endstations.

Example 3: Dynamic Egress Disabled

In this example, Dynamic Egress is disabled. When source endstation A is tagged with VLAN 5, A's ingress port is not placed on VLAN 5's egress list. GVRP places interswitch ingress ports (1) and (2) on VLAN 5's egress list. When B's traffic is tagged with VLAN 5, B's ingress port is not placed on VLAN5's egress list. GVRP places interswitch ingress ports (3) and (4) on VLAN 5's egress list. But VLAN 5 traffic for both A and B is discarded, because VLAN 5 is not aware of the ingress ports for A and B.

Example 4: Silent Endstation

In this example, Dynamic Egress is enabled for VLAN 5, but the destination endstation, B, is a "silent" endpoint, like a printer. Endstation B does not send responses, so the Administrator must place B's ingress port on VLAN 5's egress list manually (1). When A is tagged with VLAN 5, Dynamic Egress places A's ingress port (2) on VLAN 5's egress list. GVRP then places interswitch ingress ports (3) and (4), then (5) and (6) on VLAN 5's egress list. Endstation A is then able to communicate with the printer.

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Policy VLAN Islands

Policy Manager offers you the ability to set up Policy VLAN Islands which enable you to deploy a policy across your network, while restricting user access to only selected local devices. For example, if you want to have a guest VLAN but you do not want the guests in one facility to be able to communicate with guests in another facility, you can set up a VLAN island containing only selected devices in each facility, with access controlled by local VLANs.

To enable this feature, select Edit > Policy VLAN Islands Enabled from the menu. Policy Manager provides a Policy VLAN Islands Configuration Wizard which leads you through the configuration of local VLANs and the selection of the set of devices for each island. See How to Create a Policy VLAN Island for more information.

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MAC Locking

MAC Locking ensures that only specific MAC addresses can access a port, and that traffic from any other MAC addresses will be discarded. You might take advantage of MAC Locking if, for example, you want to prevent more than one user from accessing a port at a given time. There are two kinds of MAC Locking: Dynamic and Static. When you enable Dynamic MAC Locking on a port, the next MAC address that authenticates or accesses  the port (up to the maximum number of dynamic locked MAC addresses allowed) will have exclusive access to that port from that time on. Static MAC Locking lets you create a list of locked MAC addresses for a port so that the port only accepts traffic from those MAC addresses. MAC Locking is only available on devices that support it, and is not allowed on backplane and logical ports.

In order for MAC Locking to take effect on a port, it must be enabled at the device level. You can do this using the Device Configuration wizard, or the device MAC Locking tab. You can enable and disable MAC Locking for a specific port on the port MAC Locking tab. You can also enable MAC Locking for multiple selected ports in the Port Configuration wizard.

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Device Groups

Policy Manager allows devices to be combined into groups, similar to the way services can be combined into service groups. With device groups, you can perform certain operations on an entire group at once, instead of performing the operation on individual devices. A device can be a member of more than one group.

Policy Manager provides three pre-defined device groups for your convenience. You can also create your own device groups, called User-Defined Device Groups. Policy Manager pre-defined groups are displayed with blue folders. Any group you add will display a yellow folder.

Pre-Defined Device Groups

Policy Manager provides three pre-defined device groups located under the Grouped By folder in the Network Elements tab:

User-Defined Device Groups

You can also create your own device groups under the Grouped By folder. (You cannot create groups under the Device Type, IP, or Location folder.) A device group cannot have the same name as another device group at the same level.

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Port Groups

Policy Manager allows ports to be combined into groups, similar to the way services can be combined into service groups and devices can be combined into device groups. Port groups enable you to configure multiple ports on the same device or on different devices simultaneously, or to retrieve port information from them.

Policy Manager provides you with several commonly used port groups for your convenience, called Pre-Defined Port Groups. You can also create your own port groups, called User-Defined Port Groups.

Pre-Defined Port Groups

Policy Manager provides the following commonly used port groups: Every time one of the Pre-Defined Port Groups is accessed, Policy Manager goes to the devices and retrieves the ports which fit the pre-defined characteristics of the port group. Unlike the port lists for User-Defined Port Groups, Pre-Defined Port Group port lists are not saved in the Policy Manager data (.pmd) file, since the .pmd file is a user-created file. Pre-Defined Port Groups do not have Details View tab associated with them, since Details View tabs display the information from the .pmd file.

User-Defined Port Groups

Policy Manager also enables you to create your own port groups. When you create a user-defined port group, you can either select individual ports to add to the group, or specify a range or ranges of ports from all devices to be included in the group. See General Tab (User-Defined Port Group) for more information.

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Network Resource Groups

Network Resource Groups provide a quick and easy way to define Layer 3 IP address traffic classification rules for groups of network resources such as routers, VoIP (Voice over IP) gateways, and servers. The Policy Manager Demo.pmd file contains examples of network resource groups that you might want to create, such as Internet Proxy Servers and SAP Servers. You create a network resource group by defining a list of IP addresses for the devices that you want included in the group, or by choosing an IP subnet which comprises the group.

Once a network resource group has been defined, you can associate it with an Automated service (see How to Create a Service for more information). The Automated service automatically creates an IP address rule with a specified action (class of service and/or access control), for each IP address in the network resource group.

There are two ways to create a network resource group. The Network Resources Wizard leads you through all the steps required to create a network resource group and the Automated service with which to associate it, and also lets you apply the Automated service to a role. Or you can use the Create Network Resource window when you want to simply create and define a resource group that you will associate with an Automated service at a later time. Network resource groups are located in the Network Resources folder in the left-panel Network Elements tab. See How to Create a Network Resource Group for more information.

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Verifying

Verifying means comparing the roles currently in effect (enforced) on your devices with the roles defined in the Policy Manager data file currently in use (<filename>.pmd). Use this feature if you want to verify that the roles in your data file have been enforced, or, if you use more than one data file, to verify that the current file matches what is on your devices.

You can verify using the Verify (Global) button in the toolbar or the File > Verify Role Set menu option, both of which verify the information on all devices. You can also selectively verify on individual devices or device groups by right-clicking the device or group in the left panel or in the right-panel Details View tab for the Devices folder or Device Group folder, and choosing Verify Role Set from the menu.

After verifying, you see a window that reports any discrepancies. The title bar of the window lets you know if the verify was done on all devices, or a subset of devices. From this window, you can select Enforce Preview to open the Enforce Preview window, where you can view the effects enforcing the current role set would have, prior to actually enforcing.

Turning Off Verify on Startup

When Policy Manager is launched, it automatically performs the verify operation. However, this can take some time when you have many devices and roles. If it is not critical that Policy Manager and the devices be synchronized each time you launch Policy Manager, you can turn off the verify at launch by deselecting the Verify on Startup option in the Options Startup view (Tools  > Options).

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Enforcing

In Policy Manager, enforcing means writing role information to a device or devices. Any time you add, make a change to, or delete a role or any part of it (any of its services and/or rules), the devices in your network need to be informed of the change, otherwise the role will not take effect. To determine if the roles currently in effect on your devices match the set of roles you have defined in your current Policy Manager data file, (<filename>.pmd), use the Verify feature.

To enforce, use the Enforce (Global) button in the toolbar or the File > Enforce Role Set menu option, both of which write the information to all devices. You can also selectively enforce on individual devices or device groups by right-clicking the device or group in the left panel or in the right panel Details View tab for the Devices folder or Device Group folder, and choosing Enforce Role Set from the menu.

Policy Manager's Enforce Preview window enables you to view the information that will be written to your device(s), before you actually enforce. This feature is particularly useful if you have devices that only support certain aspects of policy management. The Enforce Preview window appears whenever you initiate an enforce using one of the methods mentioned above, so that you always have a chance to review the effects of enforcing prior to actually performing the enforce. You can control whether or not this view automatically appears with the Show this view on Enforce checkbox on the Enforce Preview window, or in Options window Optional Views (Tools  > Options). You can also access this window from the File > Enforce Preview menu option, and from the Enforce Preview button on the confirmation message that appears when a verify has taken place.

If you've made changes without enforcing and you attempt to close Policy Manager, you'll be asked if you want to enforce before closing. Also, if you have made changes that need to be enforced, the Enforce icon   appears on the status bar at the bottom of the Policy Manager window as a reminder. After enforcing, you see a window that reports any problems. The title bar of the window lets you know if the enforce was done on all devices, or a subset of devices.

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Related Information

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