Run new IOS without restart

[Michoud]

Is there a way I can force a router to run a different IOS image without reloading the router?

I've TFTPed a different IOS image into flash on a router but wanted to see if there was a way to have the router use the image without restarting.

 

[vipergg]

The quick answer is no . It has to be reloaded and the code must be copied from flash into RAM .

 

[Michoud]

That's what I was afraid of. Reloading routers in the wee hours of the morning it shall be then.

 

[vipergg]

If you have faith in the reload , then just use a timed reload command and it will reload itself at a given set time.

 

[burtsbees]

Like a kron job, viper? I know you can kron (not cron, like UNIX) in Cisco---works like UNIX Cron. I can't remember the other way...can you give a clue?

Burt

 

[vipergg]

Just use the reload command , type reload and then put your question mark after that and you will see that you can put in a date and time of when you want to reload the router . Just check your device clock to make sure it right before , if you use ntp then that shouldn't be a problem.

 

[vipergg]

The timed reload command is valid for any IOS device . I believe even the catos devices had a timed reset command which is the equivalent.

 

[Michoud]

The scheduled reload was the first thing that came to mind. We even use ntp. Unfortunately, my boss is not comfortable with that idea. We've decided to load the IOS on roughly 100 routers shortly before close of business. After close of business while someone is still on site, reload all routers and verify they all come back online.

 

[Belushi]

If you are interested, Cisco is working on a new style of code that allows the upgrading and reloading of different sections of code on the overall device. Therefore, only the updated process (say for instance OSPF, BGP, EIGRP, SNMP, etc.) could be upgraded and reloaded without affecting any of the other processes.

Juniper has been doing this since it's inception on their products. Cisco is catching up now.