Installing a Different Software Release on M-Series and T-Series Routers

Problem

You want to install a different release of JUNOS software on an M-series or T-series router.

Solution

First, retrieve the JUNOS install package, jinstall, from the Juniper Networks web site (http://www.juniper.net/support) and place it on a local server. You can install the software directly from the server:

	aviva@router1> request system software add validate server1:jinstall-7.4R1.7-domestic
-signed. Tgz

If you want to have a copy of the software on the router, copy it to the router. You can use SSH:

	aviva@router1> file copy server1:jinstall-7.4R1.7-domestic-signed.tgz /var/tmp
	aviva@server1's password:
	jinstall-7.4R1.7-domestic-signed.tgz 100% 64MB 774.5KB/s 01:24
	aviva@router1> file list /var/tmp
	/var/tmp:
	cores/
	install/
	jbundle-7.4jbundle-7.4R1.7-domestic-signed.tgz

You can also use FTP to install the software directly from a server:

	aviva@router1> request system software add validate ftp://aviva:prompt@
server1.mynetwork.com/jinstall-7.4R1.7-domestic-signed.tgz

If you are using anonymous FTP, just specify the name of the server:

	aviva@router1> request system software add validate ftp://server1.mynetwork.com/jinstall-
7.4R1.7-domestic-signed.tgz

If you want a copy of the software on the router, you can also copy it over with FTP:

	avive@router1> file copy ftp://aviva:prompt@
server1.mynetwork.com/jinstall-7.4R1.7-domestic
-signed.tgz /var/tmp/jinstall-
7.4R1.7-domestic-signed
	Password for aviva@server1.mynetwork.com:
	/var/home/aviva/…transferring.file.........YoE4Qe/
jinstall-7.4R1.7-domestic-signed.
	tgz100% of 63 MB 794 kBps 00m00s

After copying the software to the router, install it:

	aviva@router1> request system software add validate /var/tmp/jinstall-
7.4R1.7-domestic-signed.tgz

Once you have installed the new software version, reboot the router to activate it:

	aviva@router1> request system reboot

You can reboot directly as part of the software download process:

	aviva@router1> request system software add validate /var/tmp/ 
jinstall-
7.4R1.7-domestic-signed.tgz reboot

Discussion

JUNOS software is distributed as a set of modular software packages that contain the various components of the software. The packages include the base JUNOS operating system software, the routing software, and the forwarding software. These packages are bundled together in the jinstall package, which you use to install the software when you are upgrading. There is a domestic version for use in the United States and Canada (domestic) and a worldwide version (export) of each package. A given JUNOS software release runs on all J-series, M-series, and T-series routers, and you use the same jinstall package to upgrade the software on M-series and T-series router products.

Upgrade to a newer software release or downgrade to an older one by loading a different version of JUNOS software. You generally never downgrade except when you receive a new router that is running a more recent version than those of your other routers. Retrieve the JUNOS install package, jinstall, from the Juniper Networks web site (http://www.juniper.net/support) and copy it to a local server. The install package is a large file, so you can either install it directly from the server or, if you copy it to the router, put it on the hard disk, which has a large filesystem. A good place is /var/tmp.

When copying files to the router, you normally use SSH because SSH connections are encrypted, so your password and files are secure. FTP connections are not encrypted and hence are not secure. However, you can use FTP if you want, because all JUNOS software packages are signed and the JUNOS software validates the signature to ensure that the package has not been altered in any way. To use the router as an FTP server to transfer the files to the router when you are logged in to the server, enable FTP on the router:

	[edit]
	aviva@router1# set system services ftp
	aviva@router1# commit

You need to enable FTP only if you want to FTP something to the routerthat is, when the router is the FTP server. If the router is the FTP client and you are copying a file from an FTP server, you do not need to enable FTP on the router. The FTP client on the router is always present and running.

If you enable the FTP server, disable it after you have copied the file to the router:

	[edit]
	aviva@router1# delete system services ftp
	aviva@router1# commit

Use the request system software add command to install the new software. During the installation, the filesystem on the router's flash disk is rebuilt and all components of the JUNOS software are completely reinstalled. Configuration information from the previous software installation is retained, but the contents of logfiles might be erased. This is why you take a snapshot of the software using the request system snapshot command before you load a new version of the software (see Recipe 1.19).

In the request system software add command, include the validate option to check that the new software is compatible with your current router configuration file. When you are updating to a different release of the JUNOS software, the validation check is performed automatically.

In all these commands, the password is not displayed when you type it.

After you have installed the new software version and rebooted the router, verify that the software is operating properly. Then take another snapshot of the software.

If you don't want to rebuild the entire filesystem each time you upgrade software, you can install the software using the jbundle package:

	aviva@router1> request system software add validate /var/tmp/jbundle-
7.4R1.7-domestic-signed.tgz

jbundle installs the new software components and modifies the smallest number of files needed to move the new software version.