# Subscriber Management Attributes

E Series routers take advantage of many of the JunosE features to enable you to create the subscriber management environment that best meets your requirements. These features include:

- Authentication—Uses RADIUS to determine whether a user can access a specific service or resource.
- Accounting—Uses RADIUS and policy management to track service usage that can be used for volume-based billing.
- Dynamic address assignment—Uses RADIUS, DHCP, and profiles to dynamically allocate IP addresses to subscribers.
- Dynamic policy management—Uses policy and quality of service (QoS) management to assign and monitor subscriber bandwidth restrictions.
- Security—Uses policy management, source address validation, and media access control (MAC) address validation to grant subscriber access and to enable the use of classification when monitoring subscriber traffic flows.
- Dynamic interfaces—Automatically creates an interface column based on a catalyst packet or event.
- Marking—Uses policy management marking to enable differential treatment of specific packets.
- Policy routing—Uses policy management routing policies to assign subscriber routes that are based on classification.

## Dynamic IP Subscriber Interfaces

You can set up your subscriber management environment to create dynamic IP subscriber interfaces in two situations—when a DHCP event occurs or when a packet is detected.

In the first case, the interface is created when an external DHCP server or the DHCP local server responds to a subscriber request. In the second case, the subscriber interface is created when the router receives a packet (the packet detect feature) with a source IP address that is not in the demultiplexer table. In this second case the primary IP interface must be in autoconfiguration mode.

Subscriber management uses the following process when validating the IP source address of the packet:

- If the address is not valid, no subscriber interface is created. A discard entry is added to the demultiplexer table, and an error message is generated.
- If the address is valid with respect to the address ranges configured on the primary IP interface, subscriber management uses packet information to select the appropriate dynamic subscriber interface profile. The commands corresponding to the profile are then used to create the subscriber interface.