Juniper SYSTEM BASICS - CONFIGURATION GUIDE V 11.1.X User Manual

Figure 20: Example of IP over Ethernet Stacking Configuration Steps
Configuring IP Tunnels, Shared IP Interfaces, and Subscriber Interfaces
The E Series router supports IP tunnels, shared IP interfaces, and subscriber interfaces.
Configuring IP Tunnels
IP tunnels provide a way of transporting datagrams between routers separated by
networks that do not support all the protocols that those routers support. To configure
an IP tunnel, you must first configure a tunnel-service interface. (See “Configuring
Tunnel Service Interfaces” on page 16.)
When you have configured a tunnel-service interface, treat it in the same way as any
IP interface on the router. For example, you can configure static IP routes or enable
routing protocols on the tunnel interface. The IP configurations that you apply to the
tunnels control how traffic travels through the network.
Configuring Shared Interfaces and Subscriber Interfaces
A shared IP interface is one of a group of IP interfaces that use the same layer 2
interface. Shared IP interfaces are unidirectional—they can transmit but not receive
traffic. A subscriber interface is an extension of a shared IP interface. Subscriber
interfaces are bidirectional—they can both receive and transmit traffic.
You can create multiple shared IP interfaces over the same layer 2 logical
interface—for example, atm 5/3.101—enabling more than one IP interface to share
the same logical resources. This capability is useful, for example, when data received
in one VRF needs to be forwarded out an interface in another VRF, such as for
BGP/MPLS VPNs (see JUNOSe BGP and MPLS Configuration Guide, for more
information). You can configure one or more shared IP interfaces. Data sent over
shared interfaces uses the same layer 2 interface. You can configure shared interfaces
as you would other IP interfaces. Each shared interface has its own statistics.
The E Series router supports subscriber interfaces on a particular type of layer 2
interface, Ethernet. In the absence of VLANS, Ethernet does not have a demultiplexing
layer. A subscriber interface adds a demultiplexing layer for an Ethernet interface
that is configured without VLANs. Using subscriber interfaces, the router can
demultiplex or separate the traffic associated with different subscribers. You can use
subscriber interfaces to separate traffic for cable modem subscribers with different
levels of service and to separate traffic for VPNs.
For information about configuring shared interfaces and subscriber interfaces, see
JUNOSe IP, IPv6, and IGP Configuration Guide.
Configuring IP Tunnels, Shared IP Interfaces, and Subscriber Interfaces ■ 23
Chapter 1: Planning Your Network

Juniper SYSTEM BASICS - CONFIGURATION GUIDE V 11.1.X Specifications

General

Brand	Juniper
Model	SYSTEM BASICS - CONFIGURATION GUIDE V 11.1.X
Category	Software
Language	English