Here’s another short (but hopefully useful) post. We’ll be going through IOS Macros.

I’ve never used IOS Macros before, but I was asked about a problem today, and a macro seems to be an ideal solution. A friend of mine is an engineer for a service provider with a very large network. He has been tasked with implementing passive interfaces as the default for OSPF across the network. Most of the devices which will be modified rely on OSPF for management connectivity. When he runs the “passive-interface default” command, he will lose connectivity before he is able to run “no passive-interface [interface]” to restore connectivity. Macros tell the router to run the predetermined commands for us, which will save us from getting locked out.

The topology is simple and not worth a diagram. R1 and R2 are connected via their FastEthernet0/0 interfaces. They are running OSPF on this interface.