Wednesday, December 29, 2010

Helpful commands for anyone sitting the CCIE lab

no  whoops, I meant just -> logging synchronous
Router(config)# line con 0
Router(config-line)# logging synchronous
This command allows all of the logging output to show up on a separate line from the configuration commands you're typing at the console.  Meaning you can keep typing your commands w/o getting interrupted by a message you want to see, but don't want to be wedged in the middle of what you were trying to type. (thanks to SebaPast for being the first to set me straight!)

no ip domain-lookup
This command disables the DNS to IP domain lookup feature.  This "feature" keeps you waiting at the CLI while the AP/switch/router attempts to lookup the IP address of the invalid command you entered.

(just a link to the paragraphs and paragraphs of 'how-to' for this task)

config time ntp server 
This command works on controllers & on WCS when it is running on Linux.

When WCS is running on Windows or Linux, it checks the OS time clock every 24 hours for a time update.  If you make a change to the time - you need to stop/start the WCS service for the time change to take effect.

sntp server A.B.C.D
This command on a Cisco 1242 will point the AP to an NTP time source.

While googling SNTP I came across an article by @ioshints (wouldn't you know!) explaining SNTP Will Not Work if You've Configured NTP.  This I did not know.

I also found a great post by Adam about SNTP time sync on Cisco Aironet 1242

service timestamps debug datetime localtime show-timezone msec
service timestamps log datetime localtime show-timezone msec
logging on
logging A.B.C.D [ip address of syslog server]

logging console level
logging monitor level
logging facility facility-type

--> default is informational and lower
  • Error messages about software or hardware malfunctions, displayed at the errors level.
  • Interface up/down transitions and system restart messages, displayed at the notification level.
  • Reload requests and low-process stack messages, displayed at the informational level.
  • Output from the debug commands, displayed at the debugging level.

1 comment:

  1. Most of the time I've seen SNTP running on Windows clients, I'm surprised to see it on the AP1242. IOS routers always use NTP. I am not familiar with the location appliance (yet), but from the link you provided, it is a pure Linux ntpdate implementation. Thanks for your post.