# Overview

If the router contains only one SRP module, we recommend you divert traffic to another router before installing a new software release because the router is unavailable during the installation process. Depending on whether a firewall separates the router from the network host, you can then complete the appropriate software installation. (See Installing Software When a Firewall Exists or Installing Software When a Firewall Does Not Exist.) However, if the router contains two SRP modules, you can upgrade the software while the system is operating. (See Upgrading Systems That Are Operating with Two SRP Modules.)

When installing new JunosE Software, you must copy the contents of the release files to a network host and transfer the release files to at least one router in the network. Depending on the network configuration, you can copy the release files from either the network host or the first router to the other routers in the network. (See Copying Release Files from One Router to Another.)

| Note: Some line modules and SRP modules on ERX14xx models, ERX7xx models, and the ERX310 Broadband Services Router require a minimum amount of memory to be used with JunosE Release 5.3.0 or a higher-numbered release. See the ERX Module Guide for module specifications.

## Identifying the Software Release File

You can find the software release file in the software image bundle that you can download from the Juniper Networks website at http://www.juniper.net/customers/support. The .zip file that you download contains the software release file.

- JunosE <release> #1—Contains the release files for the ERX7xx routers, the ERX14xx routers, and the ERX310 router
- JunosE <release> #2—Contains the release file for the E120 and E320 Broadband Services Routers, the MIB directory, and the Release Notes

You can also download a compressed version of the software release by logging on to https://www.juniper.net/support/. The .zip file that you download contains the software release file.

The release is in the software directory, which is identified by the release number. For example, if the release number is x.y.z, the name of the directory is x-y-z. See Table 11.

Table 11: Software Release Files

Router | File Format (x-y-z is the release number)
--- | ---
E120 and E320 | e320_x-y-z.rel
ERX1440 | erx40_x-y-z.rel
ERX310 | erx310_x-y-z.rel
All other E Series routers | erx_x-y-z.rel

To identify the software release file:

1. Access the software directory.
2. Find the files with the extension .rel.

The procedures outlined in the following sections provide detailed instructions for typical installations. For additional information about commands and troubleshooting, see Command-Line Interface and Interface Types and Specifiers in the JunosE Command Reference Guide