My “Show Run Variations” post sparked an interesting thread on Networking-Forum. I thought it would be nice to make a post with as many useful/little known commands as I can find. I might make a separate page for this depending on how much I can come up with and how frequently updates would be needed. Here we go:

show ip nbar protocol-discovery stats bit-rate top-n 10

This command will show you the top 10 protocols (that NBAR can see) on your router. I use this in an alias called “traffic”. You will also need “ip nbar protocol-discovery” enabled on interfaces you want to see statistics for.

show processes cpu sort

This command will show the sorted CPU usage of all processes running on the router. You could also use “show proc cpu history” to see some ASCII graphs of CPU utilization.

reload in 5

This command is invaluable. I have used it many times when making a change that could lock me out of the router, I’ve also forgotten to use it and regretted it a few times, lol. This command will reload the router in the time you specify. The “reload cancel” command should be used after the change has been made successfully.

do _____

Most people use this on a daily basis, I’m sure. For those who don’t know about it, it’s used from config mode when you want to execute something from exec mode. So something like “do sh ip int b” could be run while you’re in global config mode.

default interface <int>

This command will reset an interface (or a range of interfaces) back to its default config.

show ip flow top-talkers

This command will show the top NetFlow information for all ports with “ip flow” configured. Typically you would get this information from a NetFlow collector, but this command can be useful on the fly.

show ip bgp rib-failure

This I learned from Darren’s Blog. It shows what is causing a RIB Failure preventing certain entries from being valid in the BGP table.

show ip route profile

I just learned about this command on Stretch’s Blog. He explains it better than I could.

I will be periodically updating this post, or making a special page for this. Here are the aliases I currently have on my router:

alias exec traffic sh ip nbar protocol-discovery stats bit-rate top-n 10
alias exec s sh ip int b
alias exec sir show ip route
alias exec sion show ip ospf neighbor
alias exec svb show vlan-switch brief
alias exec sr show run
alias exec sal show access-lists
alias exec srm sh route-map
alias exec proc show proc cpu sort | excl 0.00%__0.00%__0.00%
alias exec salsec sh ip access-list | sec
alias exec spmo show policy-map int fa0/1 out
alias exec spmi show policy-map int fa0/1 in
alias exec sift sh ip flow top

Those are my most used commands.


Colby Glass has been in IT since 2002. He is currently a Systems Engineer (presales) with a Cisco Gold partner and holds the CCNP R/S, CCNP DC, CCDP, CCIP, JNCIA-ER.

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