Have you ever been on your GradedLabs rack of equipment and wanted to test a particular feature or set of configurations, but you certainly do not want to keep these changes on the rack? Perhaps this is because you are right in the middle of solving a Volume 2 lab and you certainly cannot have that configuration impacted.
Thanks to the very handy config replace command, you can easily rollback almost instantly to your previous saved configuration after your experimenting. Here is a demonstration of just how simple this is. Enjoy, and let us give thanks for all there is to learn on blog.ine.com! :-) I also want to thank my good friend Keith Barker for first showing me this one.
Enter configuration commands, one per line. End with CNTL/Z.
TEST(config-if)#ip address 188.8.131.52 255.0.0.0
TEST#config replace nvram:startup-config force
Total number of passes: 1
Rack29R1#show run interface fa0/0
Current configuration : 83 bytes
no ip address