Related Documentation
Before You Begin
Before you begin a unified ISSU, complete the tasks in the following sections:
- Verify That the Master and Backup Routing Engines Are Running the Same Software Version
- Back Up the Router Software
- Verify That Graceful Routing Engine Switchover and Nonstop Active Routing Are Configured
Verify That the Master and Backup Routing Engines Are Running the Same Software Version
To verify that both Routing Engines are running the same version of software, issue the following command:
{master}
user@host> show version invoke-on all-routing-engines
re0: -------------------------------------------------------------------------- Hostname: host Model: m320 JUNOS Base OS boot [9.0-20071210.0] JUNOS Base OS Software Suite [9.0-20071210.0] JUNOS Kernel Software Suite [9.0-20071210.0] JUNOS Crypto Software Suite [9.0-20071210.0] JUNOS Packet Forwarding Engine Support (M/T Common) [9.0-20071210.0] JUNOS Packet Forwarding Engine Support (M320) [9.0-20071210.0] JUNOS Online Documentation [9.0-20071210.0] JUNOS Routing Software Suite [9.0-20071210.0] re1: -------------------------------------------------------------------------- Hostname: host Model: m320 JUNOS Base OS boot [9.0-20071210.0] JUNOS Base OS Software Suite [9.0-20071210.0] JUNOS Kernel Software Suite [9.0-20071210.0] JUNOS Crypto Software Suite [9.0-20071210.0] JUNOS Packet Forwarding Engine Support (M/T Common) [9.0-20071210.0] JUNOS Packet Forwarding Engine Support (M320) [9.0-20071210.0] JUNOS Online Documentation [9.0-20071210.0] JUNOS Routing Software Suite [9.0-20071210.0]
If both Routing Engines are not running the same software version, issue the request system software add command on the desired Routing Engine so that the software version is the same. For more information, see the Installation and Upgrade Guide.
Back Up the Router Software
As a preventive measure in case any problems occur during an upgrade, issue the request system snapshot command on each Routing Engine to back up the system software to the router’s hard disk. The following is an example of issuing the command on the master Routing Engine:
{master}
user@host> request system snapshot
Verifying compatibility of destination media partitions... Running newfs (220MB) on hard-disk media / partition (ad1s1a)... Running newfs (24MB) on hard-disk media /config partition (ad1s1e)... Copying '/dev/ad0s1a' to '/dev/ad1s1a' .. (this may take a few minutes) Copying '/dev/ad0s1e' to '/dev/ad1s1e' .. (this may take a few minutes) The following filesystems were archived: / /config
![]() | Note:
The root file system is backed up to |
Verify That Graceful Routing Engine Switchover and Nonstop Active Routing Are Configured
Before you begin a unified ISSU, ensure that graceful Routing Engine switchover and nonstop active routing are configured on your router.
- To verify that graceful Routing Engine switchover is configured,
on the backup Routing Engine (re1) issue the show system switchover command. The output should be similar to the
following example. The Graceful switchover field state
must be On.
{backup}
user@host> show system switchover
Graceful switchover: On Configuration database: Ready Kernel database: Ready Peer state: Steady State
- To verify that nonstop active routing is configured, on
the master Routing Engine (re0) issue the show task replication command. The output should be similar to the following
example.
{master}
user@host> show task replication
Stateful Replication: Enabled RE mode: Master Protocol Synchronization Status OSPF Complete IS-IS Complete
If graceful Routing Engine switchover and nonstop active routing are not configured, complete the following steps:
- On the master Routing Engine (re0), enable graceful Routing Engine switchover. Include the graceful-switchover statement at the [edit chassis redundancy] hierarchy level.
- On the master Routing Engine, enable nonstop active routing. Include the commit synchronize statement at the [edit system] hierarchy level and the nonstop-routing statement at the [edit routing-options] hierarchy level.
- On the master Router Engine, issue the commit command.
The system provides the following confirmation that the master and backup Routing Engines are synchronized:
re0: configuration check succeeds re1: commit complete re0: commit complete