Beginning with this release of JUNOS software, you can configure a subscriber interface using a static or dynamic IP demultiplexing (demux) logical interface stacked on an aggregated Ethernet logical interface. You must configure the aggregated Ethernet logical interface on Enhanced Queuing Dense Port Concentrators (EQ DPCs) in an MX-series router. Prior to this release of JUNOS software, IP demux subscriber interfaces were supported only over Gigabit Ethernet, Fast Ethernet, and 10-Gigabit Ethernet links that were not part of an aggregated Ethernet bundle.
Subscriber interfaces on static or dynamic IP demux interfaces can be used to identify specific subscribers (authenticated users) in an access network or to separate individual circuits. A subscriber interface on a static or dynamic IP demux interface over aggregated Ethernet can support one-to-one active/backup link redundancy or traffic load balancing, depending on how you configure the underlying aggregated Ethernet interface.
To configure a static or dynamic IP demux subscriber interface over aggregated Ethernet, make sure you understand the following concepts:
The following points describe the relationship between a static or dynamic IP demux subscriber interface and the underlying aggregates Ethernet logical interface:
Traffic forwarding through a IP demux logical interface is dependent on the configuration of the underlying logical interface. Using an aggregated Ethernet logical interface as the underlying interface for a static or dynamic IP demux subscriber interface provides you with the following options:
1:1 Active/Backup Link Redundancy
If you need to support one-to-one active/backup link redundancy, configure the aggregated Ethernet interface in link protection mode, which requires that two underlying physical interfaces be designated as primary and backup links. In addition, if you need to support one-to-one active/backup link redundancy at the DPC level, configure the aggregated Ethernet interface on physical interfaces that reside on different EQ DPCs.
Load Balancing
If you need to support traffic load balancing instead of redundancy, configure the aggregated Ethernet interface to operate in Link Aggregation Control Protocol (LACP) active mode. When using LACP link protection, you can configure only two member links to an aggregated Ethernet interface: one active and one standby. The JUNOS implementation of the IEEE 802.3ad standard balances traffic across the member links within an aggregated Ethernet bundle based on the Layer 3 information carried in the packet.
For more information about aggregated Ethernet interfaces, see the JUNOS Network Interfaces Configuration Guide.
Table 26 lists key subscriber access features supported with static or dynamic IP demux subscriber interfaces, organized by type of underlying logical interface:
In this release of JUNOS software, no feature limitations are specific to IP demultiplexing. Instead, IP demux interfaces over aggregated Ethernet are subject to the same scaling and configuration limitations inherent to aggregated Ethernet logical interfaces.
Table 26: Features Supported with Static or Dynamic IP Demux Subscriber Interfaces