35 days and counting: Why one bad day shouldn't dishearten you


It's a mere thirty-five days till the lab exam, and I had a complete shocker of a study time today.

So far, things have been steadily improving. My speed is getting better, and the process is getting honed. This does not help, though, for those days when things just don't click.

I want to put it down to having too many interruptions during the day.

First came a wine delivery, from Naked Wines - after studying for hours who doesn't like a glass of wine!

Then there was another delivery, this time it was Brad Klausen's Flight to Mars poster:

Beautiful, isn't it? Going to get it framed.

Next was some more post, including some Croc shoes (with lights for one of the boys).

Next was the cleaner.

So, lots of interruptions. But really, this should not be a reason for:

1: Not reading requirements properly
2: Not reading IP addresses, and typing in the wrong IP addresses
3: Assuming that basic things have been done.

1 and 2 are pretty self-explanatory. but let's take an example for #3 (which also links to #1).

We are faced with a number of switches. Routers connect to these switches, in different VLANs. The requirements are to put all the interfaces in the correct VLANs, make sure that the trunks use dot1q encapsulation. Not too difficult, right?

Depending on what you are studying, you'll either have a diagram with the interfaces labelled, or, at worst, you'll need to get onto each of the routers and to a "sh cdp neigh", a "sh ip int bri | e unas", and from there work out the correct vlans to put the switch interfaces into. Either way, it shouldn't be too traumatic.
So, i had a long text document with the interface to vlan assignments, worked this down into a number of easy-to-paste lines, and pasted them on. I had partial router-to-router connectivity, but others were dead in the water. I checked and double checked. The interfaces were in the correct VLANs. The VLANs were in the database. The interfaces were up/up on both the routers and the switches, and the IP addresses were checked and double checked.

Eventually, after running "sh int trunk", I saw that the trunk interfaces were set to use ISL encapsulation, not dot1q.

This is something that I should have picked up on earlier (ideally). I missed this because:

A: I did not fully read the requirements (overlaps with B)
B: I made an assumption
C: My process did not include this (again this overlaps with B).

I did read the requirements, but my assumption, because dot1q is the standard, overruled sense. Because dot1q is the standard my assumption did not factor an alternative into my process

So, although it took longer, eventually I did finish all of the tasks. If it were the real exam I would have failed.

There is, however, and upside.

I still have time, therefore I can learn from this mistake. I have learned (I hope), not to make assumptions, and this issue (ISL vs dot1q) is not part of my process, the both troubleshooting and configuration.

So, long story short, the take home from this is that the process has changed, and a lesson has been learnt.

Now I am sitting here, drinking a nice glass of wine.

Onwards and upwards. Let's see what the next thirty (or so) days bring!

Cheers!

CCIE #49337, author of CCNA and Beyond, BGP for Cisco Networks, MPLS for Cisco Networks, VPNs and NAT for Cisco Networks.

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