Some of these shortcuts I’ve used for a long time, and a couple of them I learned today. I can’t believe I’ve gone so long without knowing how to go to the beginning of a line. My left arrow key is going to miss me.
CTRL-A will take you to the beginning of a line. Very handy for negating a configuration item like this:
no ip route 10.10.10.10 255.255.255.0 184.108.40.206
CTRL-E will take you to the end of the line. Not as handy but at least you know how to move around now.
The default command will set an interface (and many other configuration items) to their default settings. This is very handy if you have complex interface configurations and you want to start from scratch without removing the configuration line by line.
default interface Fa0/0
Learn the short-hand available on your platform. I didn’t realize the time-savings of this method until I saw a TAC engineer do this, and now I am addicted to it. If you look at this configuration:
switchport trunk encapsulation dot1q
switchport mode trunk
switchport trunk allowed vlan 10,100,2000-2010
copy running-config startup-config
You can do the same thing with a lot less typing, and you don’t have to tab-complete all the time either:
sw tr en do
sw mo tr
sw tr al vl 10,100,2000-2010
cop ru st
This saves time, and whether you’re designing, testing, configuring or troubleshooting it pays to get more work done in less time.
You can add or remove VLANs from a trunk without having to type the whole line:
switchport trunk allowed vlan remove 100
switchport trunk allowed vlan add 200
On all platforms you can use the | include command to match basic text searches on any show command:
show run | include username
This command easily shows the usernames and privilege levels of those users in the configuration.
This handy command shows only CPU processes that are actually using CPU cycles, and it illustrates the | exclude command to filter out text:
show proc cpu | exclude 0.00
I often want to see configuration that I know starts somewhere in the middle, or bottom of the config. On simple router configs it isn’t a big deal to page through the data, but complex switches like the 6500 series can easily get to be thousands of lines long and paging through all that can get tiring (and boring). Use the | begin command to match text and start showing the configuration there:
show run | begin vty
This will start displaying the configuration at the first line that matches “vty” and now you can review your remote access configuration without having to hit the space bar a few hundred times.
On router platforms you can use the | section command to match entire sections of the configuration:
show run | section router
This will list the full configuration of any dynamic routing protocols you have configured. Try this on a CME router and you’ll really be happy when you can list all the configured ephones and ephone-dns:
show run | section ephone-dn
If you’re testing the bandwidth of a link you might want to get interface statistics:
show interface Gi0/8 | i rate
Queueing strategy: fifo
5 minute input rate 3000 bits/sec, 3 packets/sec
5 minute output rate 4000 bits/sec, 4 packets/sec
But you’ll notice this is a 5 minute statistic, which means you’ll have to be loading this interface for at least 5 minutes before you get a true reading. For the impatient there is a solution, we can set the statistical interval to 30 seconds (the minimum):
sh int gi 0/8 | i rate
Queueing strategy: fifo
30 second input rate 1000 bits/sec, 1 packets/sec
30 second output rate 1000 bits/sec, 1 packets/sec
That’s better – now you only have to load the interface for 30 seconds to figure out the utilization. As far as data-rate analysis goes it is as close as you need to get most of the time; you’ll have to use different methods to get more granular than this.