CCIE Pursuit Blog

April 28, 2007

How to Schedule a Reload

Filed under: Cool Commands — cciepursuit @ 12:23 pm

It has happened to all of us at some time: you’re working on an access-list or an interface configuration when suddenly you’re locked out of the router.  While desperately trying to telnet back to the router it slowly dawns on you: you’ve just made a change to the router that has effectively locked you out of the device.  The good news is that you didn’t write the configuration so you just need to reload/power cycle the device.  The bad news is that the device is at a remote site and it’s 2 am.  The call to the site contact to drive to the site and reboot the router is only going to be slightly less pleasurable than the Monday morning meeting with your supervisor where you get to explain why you made a service-affecting change without proper authorization. :)

One way to avoid this situation is to schedule a router reload so that if you get locked out of the box, you simply need to wait for the reload to take place and then get back in.

You can schedule the reload to happen at a specific time of day* (reload at) or at the end of a certain interval (reload in):

Reload In x

reload in ?
Delay before reload (mmm or hhh:mm)

r1#reload in 1
Reload scheduled in 1 minute by console
Proceed with reload? [confirm]
r1#
***
*** — SHUTDOWN in 0:01:00 —
***

Reload at xx:xx

r1#reload at 10:01

System configuration has been modified. Save? [yes/no]: y
Building configuration…
[OK]
Reload scheduled for 10:01:00 UTC Sat Apr 28 2007 (in 37 seconds) by console
Proceed with reload? [confirm]
r1#
Apr 28 10:00:26: %SYS-5-SCHEDULED_RELOAD: Reload requested for 10:01:00 UTC Sat
Apr 28 2007 at 10:00:08 UTC Sat Apr 28 2007 by console.

So you’ve set the router to reload in 30 minutes while you complete your change.  You complete the change successfully.  How do you cancel the ticking time-bomb of the impending router reload?  Simply enter the “reload cancel” command:

Reload Cancel

r1#reload cancel
r1#
***
*** — SHUTDOWN ABORTED —
***

Being able to schedule a reload is a great feature and has saved my bacon more than once.  The biggest thing to remember is to disable the router reload once you have successfully completed your change.  To verify whether there are scheduled reloads, run the “show reload” command:

Show Reload

r1#show reload
Reload scheduled in 4 minutes and 55 seconds by console
Reload reason: Scheduled reload

You can optionally provide a reason for the reload.  This will show up with “show reload” but will not survive the reload itself (I was hoping that it would show up in the “show version” output):

Reason For Reload

r1#reload in 1 ?
  LINE  Reason for reload
  <cr>

r1#reload in 2 ROUTER_WAS_NAUGHTY
Reload scheduled in 2 minutes by console
Reload reason: ROUTER_WAS_NAUGHTY
Proceed with reload? [confirm]
r1#sh
*Mar  1 01:37:34: %SYS-5-SCHEDULED_RELOAD: Reload requested for 01:39:33 UTC Mon Mar 1 1993 at 01:37:33 UTC Mon Mar 1 1993 by console. Reload Reason: ROUTER_WAS_NAUGHTY.
r1#sh reload
Reload scheduled in 1 minute and 55 seconds by console
Reload reason: ROUTER_WAS_NAUGHTY
r1#
***
*** — SHUTDOWN in 0:01:00 —
***

r1#
***
*** — SHUTDOWN NOW —
***

r1#
*Mar  1 01:39:34: %SYS-5-RELOAD: Reload requested by console. Reload Reason: ROUTER_WAS_NAUGHTY.

*****After the reload****

r1#sh ver
Cisco Internetwork Operating System Software
IOS ™ C2600 Software (C2600-IS-M), Version 12.3(22), RELEASE SOFTWARE (fc2)

r1 uptime is 2 minutes
System returned to ROM by reload
System image file is “flash:c2600-is-mz.123-22.bin”

This command can also be used for evil.  Let’s say – totally hypothetically – that you are in a training class and your buddy did not secure his router.  You could – again this is a hypothetical and cannot be used as evidence of past misuse – enter “write erase” followed by “reload in 1 CUZ_UR_N00B”.  Your buddy had better know about the “reload cancel” command or he may be doing a lot of reconfiguring :)

The Last Thing Your Buddy Might See

***
*** — SHUTDOWN in 0:01:00 —
***

r2#
*Mar  1 05:19:43.554: %SYS-5-SCHEDULED_RELOAD: Reload requested for 05:20:29 UTC
 Mon Mar 1 1993 at 05:19:29 UTC Mon Mar 1 1993 by vty0 (155.1.146.1). Reload Rea
son: CUZ_UR_N00B.
r2#
***
*** — SHUTDOWN NOW —
***

r2#
*Mar  1 05:20:43.066: %SYS-5-RELOAD: Reload requested by vty0 (155.1.146.1). Rel
oad Reason: CUZ_UR_N00B.
r2#
System Bootstrap, Version 12.2(10r)1, RELEASE SOFTWARE (fc1)
TAC Support: http://www.cisco.com/tac
Copyright (c) 2002 by cisco Systems, Inc.
C2600 platform with 65536 Kbytes of main memory

program load complete, entry point: 0x80008000, size: 0x1134810
Self decompressing the image : #################################################

No!!!!!!!!!!

Command Reference

reload
To reload the operating system, use the reload command in privileged EXEC mode.

reload [/verify | /noverify] [warm [file url]] [in [hh:]mm | at hh:mm [month day | day month]] [cancel] [text]

* In order for this command to work, you must be running NTP or have the time set on your router.  To set the time use the “clock set” command from the enable prompt (not in configuration mode):

r1#clock set 10:00:00 April 28 2007
r1#show clock
r1#10:00:03.391 UTC Sat Apr 28 2007

If you set the clock with “clock set”, the clock setting will not survive the reload.

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