DHCP Subscriber Interface Overview
You can identify subscribers statically or dynamically.
To identify subscribers statically, you can reference a static VLAN interface in a dynamic profile. To identify subscribers dynamically, you create variables for demux interfaces that are dynamically created by DHCP when subscribers log in.
Statically Identifying Subscribers
Before you can configure static subscriber interfaces in a dynamic profile, you must first configure the logical interfaces on the router to which you expect clients to connect. After you have created the static interfaces, you can modify them by using dynamic profiles to apply configuration parameters.
You can also configure subscribers by creating sets of static IP demux interfaces that are not referenced in a dynamic profile.
When configuring the interfaces stanza within a dynamic profile,
you use variables to specify the interface name and the logical unit
value. When a DHCP subscriber sends a DHCP request to the interface,
the dynamic profile replaces the interface-name and unit variables with the actual interface name and logical unit
number of the interface that received the DHCP request. After this
association is made, the router configures the interface with any
CoS or protocol (that is, IGMP) configuration within the dynamic profile,
or applies any input or output filter configuration that you have
associated with that dynamic profile.
[edit dynamic-profiles] interfaces interface-name { unit logical-unit-number { family family { address address; filter { input filter-name; output filter-name; } unnumbered-address interface-name <preferred-source-address address>; vlan-id; } vlan-tagging; }
Dynamically Identifying Subscribers
You can configure demux interfaces to represent a subscriber interface in a dynamic profile. When a subscriber logs in using a DHCP access method, the demux interface is dynamically created.
You specify variables for the unit number, the name of the underlying interface, and the IP address in the dynamic profile. These variables are replaced with the values that are supplied by DHCP when the subscriber logs in.