Three configuration management features I like about Cisco IOS XR

I like more and more about Cisco IOS XR after I start to play with it. Here are three quick things I like about IOS XR.

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Uncommitted configuration can be seen as a configuration sandbox.

This feature is obvious. Before I execute “commit” command, I can review the content of my configuration to-be-applied again and again to make sure they are correct just by repeating “show configuration” command. If somehow I do not like them, I can still do partial re-configurations, or just execute “abort” command to clear everything uncommitted.

Here is one example.

RP/0/0/CPU0:R1#conf
Fri Feb 20 16:44:08.800 UTC
RP/0/0/CPU0:R1(config)#hostname R77
RP/0/0/CPU0:R1(config)#abort
RP/0/0/CPU0:R1#

This is just like a sandbox for anyone to create temporary configurations and they can be cleared easily without touching active ones.

In addition to reviewing the configuration, it is also helpful for me to do temporary demonstrations to audiences without touching anything important. The commands are still parsed and checked. And this is almost impossible in Cisco IOS.


Use “show configuration” to expand abbreviated commands.

For me to speed up my command typing, I often use abbreviations. If I want to make sure the expanded commands are correct, I can also use “show configuration” command to expand for me.

Here is one example.

RP/0/0/CPU0:R1#conf
Fri Feb 20 16:25:06.108 UTC
RP/0/0/CPU0:R1(config)#int g0/0/0/0
RP/0/0/CPU0:R1(config-if)#ip addr 1.2.3.4/24
RP/0/0/CPU0:R1(config-if)#no shut
RP/0/0/CPU0:R1(config-if)#show config
Fri Feb 20 16:25:18.598 UTC
Building configuration...
!! IOS XR Configuration 5.2.2
interface GigabitEthernet0/0/0/0
 ipv4 address 1.2.3.4 255.255.255.0
 no shutdown
!
end

Every committing creates a checkpoint at the same time.

Even after I committed the configurations, I can still rollback my active configuration easily by “do rollback configuration last 1” command to “undo” my last changes to active configuration.

Here is one example.

RP/0/0/CPU0:R1#conf
Fri Feb 20 16:30:08.388 UTC
RP/0/0/CPU0:R1(config)#hostname R99
RP/0/0/CPU0:R1(config)#commit
Fri Feb 20 16:30:15.947 UTC
RP/0/0/CPU0:R99(config)#do rollback configuration last 1
Fri Feb 20 16:30:29.636 UTC
Loading Rollback Changes.
Loaded Rollback Changes in 1 sec
Committing.
1 items committed in 1 sec (0)items/sec
Updating.
Updated Commit database in 1 sec
Configuration successfully rolled back 1 commits.
RP/0/0/CPU0:R1(config)#

One more thing...

Doing copy and paste of some working configuration is really dangerous when I configure in Cisco IOS. They are "committed" immediately and always touch my active configurations. If somehow I want to undo, I have to check line by line to undo the pasted commands. This is really annoying.

In Cisco IOS XR, I do not have this problem because before I do "commit", any pasting are just inside the sandbox. I can paste, and review them again and again, before I do the real "commit".

I like IOS XR. And what do you think about IOS XR? Please share your opinions with me by leaving comments below!