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Config snippets : Cisco: Reload command might be handy

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Few times in the past when I was doing some changes on Cisco devices remotely I was a victim of myself, when wrong order of commands just disconnected me from device without ability to connect back. After few experiences of this kind I discovered magic command “reload” which can help and save the day.

So, when doing changes which can impact remote terminal connection to device it’s a good idea to initiate reload before making changes. In case something goes wrong device will reboot itself and will come back with previous configuration.

lab-r01#
lab-r01#reload in 15
Reload scheduled in 15 minutes by admin on console
Reload reason: Reload Command
Proceed with reload? [confirm]
lab-r01#
*Mar  1 03:11:11.659: %SYS-5-SCHEDULED_RELOAD: Reload requested for 03:26:09 UTC Fri Mar 1 2002 at 03:11:09 UTC Fri Mar 1 2002 by admin on console. Reload Reason: Reload Command.
lab-r01#

Once everything is configured and connectivity to device was not lost we can cancel reload process.

lab-r01#
lab-r01#reload cancel
lab-r01#

***
*** --- SHUTDOWN ABORTED ---
***

*Mar  1 03:11:19.415: %SYS-5-SCHEDULED_RELOAD_CANCELLED: Scheduled reload cancelled at 03:11:19 UTC Fri Mar 1 2002
lab-r01#

It is very helpful and can save time and rescue from trouble.

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Config snippets : Setting NTP server on Cisco IOS device

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Quick config snippet to setup external NTP server to synchronize time on Cisco IOS router.

labisr-01(config)#ip name-server 4.2.2.2
labisr-01(config)#ntp server 0.europe.pool.ntp.org
Translating "0.europe.pool.ntp.org"...domain server (4.2.2.2) [OK]
labisr-01(config)#clock timezone GMT 0
labisr-01(config)#
Please note that first I setup nameserver on router to be able to resolve NTP server FQDN.

Once NTP server is set we can check status of it:

labisr-01#sh ntp associations
address         ref clock     st  when  poll reach  delay  offset    disp
*~88.191.227.26    82.197.188.130    3    37    64  377    38.7    2.04     1.4
* master (synced), # master (unsynced), + selected, - candidate, ~ configured
labisr-01#
labisr-01#sh ntp status
Clock is synchronized, stratum 4, reference is 88.191.227.26
nominal freq is 250.0000 Hz, actual freq is 250.0000 Hz, precision is 2**18
reference time is D442C30E.7A93ED17 (22:58:22.478 GMT Mon Nov 5 2012)
clock offset is 2.0449 msec, root delay is 71.69 msec
root dispersion is 61.25 msec, peer dispersion is 1.36 msec
labisr-01#
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Config snippets : Timezones for Cisco devices

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One thing which came handy for me was list of timezones I can use on Cisco devices. That came very useful during NTP deployment. So, here is is… timezones available for use on Cisco platform.

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Config snippets : Cisco : First time 881w ISR with AP configurarion

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When I got cisco 881w first time it was interesting experience. This device presented new concept which was different to model I knew so far, which is 871w. In 881w router module and wireless module are separated. With that being said, router configuration and access point configuration is separated as well. Also, each module (router and access point) has own IOS:

  • c880data-universalk9-mz.152-1.T1 – router IOS
  • ap801-k9w7-mx.124-21a.JA1 – access point IOS

As usual, first I connected device to console cable and attempted to configure it. Not being familiar with new concept it was a bit of a failure 🙂 So, eventually had to refer to documentation to find out what’s going on. Problem which came up was, how to access wireless module to configure it or even check if it’s there 🙂

So, finally after I did apply reading ability and spent few minutes with Cisco documentation I was able to access wireless module and configure it to provide wireless services in the air. Here is how that happend:

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Config snippets : Cisco : Testing RADIUS authentication on IOS

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Recently was migrating RADIUS server on Windows from one machien to another. Once new serer was ready had to reconfigure Cisco router to authenticate remote users against new RADIUS. After pointing Cisco to new RADIUS machine made a quick test to check if router can authenticate without any issues. Here is how ot do it quickly:

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