Cisco CCNA / CCNP Certification Exam: Same Command, Different Results
As a CCNA or CCNP, one thing you’ve got to get used to is that change is constant. Cisco regularly issues new IOS versions, not to mention the many different kinds of hardware they produce! While it’s always nice to have “the latest and the greatest” when it comes to routers, switches, firewalls, etc., we have to be prepared for the fact that not all our clients are going to have that latest and greatest!
For instance, there are still quite a few Catalyst 5000 switches out there humming away, and if you’re used to working on IOS-driven switches like the 2950, the same command can have dramatically different results.
Let’s say you’re going to examine the spanning tree protocol (STP) setup of a new client. You’re used to working with newer 2950 switches, and you’ve always run show span on those switches to display spanning-tree information. Then, you run show span on a Catalyst 5000 – and something like this shows:
switch (enable) show span
Destination : Port 6/1
Admin Source : Port 6/2
Oper Source...