Example: Configuring Shared IP Interfaces

This example shows you how to create and configure shared IP interfaces.

• Requirements
• Overview
• Configuring Shared IP Interfaces

Requirements

• JunosE Release 7.1.0 or higher-numbered releases
• E Series router (ERX7xx models, ERX14xx models, the ERX310 router, the E120 router, or the E320 router)
• ASIC-based line modules that support Fast Ethernet or Gigabit Ethernet

Overview

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.

Configuring Shared IP Interfaces

Step-by-Step Procedure

1. Create a layer 2 interface.
   host1(config)#interface atm 5/3 host1(config-if)#interface atm 5/3.101
2. (Optional) Create a primary IP interface.
   host1(config-if)#ip address 10.1.1.1 255.255.255.255 host1(config-if)#exit
3. Create the shared IP interface.
   host1(config)#interface ip si0
4. Associate the shared IP interface with the layer 2 interface by one of the following methods:
   • Statically
     host1(config-if)#ip share-interface atm 5/3.101
   • Dynamically
     host1:vr-a:vrf-1(config-if)#ip share-nexthop 10.0.0.1
5. To fully configure the shared interface, assign an address (or make the interface unnumbered).
   host1(config-if)#ip address 2.2.2.2 255.0.0.0

Related Documentation

• Shared IP Interfaces Overview
• IP Shared Interface Statistics Overview
• Monitoring IP Shared Interfaces
• interface atm
• interface ip
• ip address
• ip share-interface
• ip share-nexthop