Technical Documentation

underlying-interface (demux0)


underlying-interface underlying-interface-name;

Hierarchy Level

[edit dynamic-profiles profile-name interfaces demux0 interface-name unit unit logical-unit-number demux-options]

Release Information

Statement introduced in JUNOS Release 9.3.

Support for aggregated Ethernet added in JUNOS Release 9.4.


Configure the underlying interface on which the demultiplexing (demux) interface is running.


underlying-interface-name—Either the specific name of the interface on which the DHCP discover packet arrives or one of the following interface variables:

  • $junos-underlying-interface when configuring dynamic IP demux interfaces.
  • $junos-interface-ifd-name when configuring dynamic VLAN demux interfaces.

The variable is used to specify the underlying interface when a new demux interface is dynamically created. The variable is dynamically replaced with the underlying interface that DHCP supplies when the subscriber logs in.

Note: Logical demux interfaces are currently supported on Gigabit Ethernet, Fast Ethernet, 10-Gigabit Ethernet, or aggregated Ethernet interfaces.

Required Privilege Level

interface—To view this statement in the configuration.

interface-control—To add this statement to the configuration.

Published: 2010-04-15