# Before You Configure Bridged IP

Before you configure bridged IP on an ATM interface, verify that:

- You have correctly installed a module that supports bridged IP. For information, see ERX Module Guide, Appendix A, Module Protocol Support (on ERX7xx models, ERX14xx models, and the ERX310 router) or E120 and E320 Module Guide, Appendix A, IOA Protocol Support (on the E120 or the E320 router).
- Each configured line can transmit data to and receive data from your switch connections.

Table 25 lists the prerequisite tasks for configuring bridged IP and the resources that you can consult to learn how to perform these tasks.

Table 25: Prerequisite Tasks for Configuring Bridged IP

To Learn About | See
--- | ---
Preconfiguration and hardware diagnostic procedures | ERX Hardware Guide E120 and E320 Hardware Guide
Configuring T3 and E3 line modules | Chapter Configuring T3 and E3 Interfaces in JunosE Physical Layer Configuration Guide
Configuring OC3 line modules | Chapter Configuring Unchannelized OCx/STMx Interfaces in JunosE Physical Layer Configuration Guide

Also have the following information available:

- Interface specifiers for the ATM interfaces on which you want to configure bridged IP

  For more information about specifying ATM interfaces and subinterfaces on E Series routers, see Interface Types and Specifiers in JunosE Command Reference Guide.

- Subinterface numbers for each logical interface that you want to create
- Virtual path and channel numbers for each virtual circuit that you want to create
- IP addresses and subnet mask assignments for IP interfaces
- IP address of the DHCP server