Author Archives: kencelenza - Page 2

Your Greatest Weakness – Part 2 (23 of 30)

If you missed Part 1 check it out here, otherwise let’s jump right into it.

In-depth learning
I started last post with being a config wiz, the reality was the next phase was to sure up my networking knowledge. Go beyond understanding the configs, and truly understand how to breakdown every technology. Learn what to look for in Wireshark capture, or in-depth knowledge of each protocol knowing each knob to turn and configure. It really helps you in design, troubleshooting and just about every other aspect.… Read more

Config Templates Take 3 (22 of 30)

This is the 3rd part of a series of post’s on developing a Config Template tool, click this link to follow the whole series of post’s.

Sometimes the template system can only take you so far, and you have to get down to regular programming. The HTML::Template system will at least let you send the configs within the same tmpl file as a variable. In this example we let the user input ip networks in a form, and then split it up, however many times you put IPs in and put it into a wildcard networks.… Read more

Your Greatest Weakness – Part 1 (21 of 30)

One of those age old Interview questions, that you always hear about, “What is your greatest weakness,” and you have probably been prepared to how to answer it. I first picked up on this watching “the Simpsons.”

Smithers: What would each of you say is your worst quality?
Man 1: Well, I a workaholic.
Man 2: I push myself too hard.
Homer: Well, it takes me a long time to learn anything,
I’m kind of a goof-off…
Smithers: Okay, that’ll do.

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Route View Script (20 of 30)

I created a script that logs into route servers ( I used the ones found here routeserver) and checks for networks that you define. All you have to do is define the networks with edge ASN, this way it can tell you which last hop ASN it took from that route server, and you can match that to your peer’s ASN.

There is basically two files, the configs file, which comes pre-populated with the route servers from the server above, and the script itself named… Read more

How to be a Better Speaker (19 of 30)

Now this doesn’t pertain to public speaking, which most of us won’t be doing all that much, but rather how to be better heard in meetings, especially highly technical meetings where ego can get in the way.

TLDR: Listening

It’s that simple, everyone wants to be heard, and they are not listening to you if they don’t get a voice as well. I read this somewhere (lifehacker??) several years ago and have employed the technique in my day to day since then.… Read more

IP Network Parser (18 of 30)

Assuming you have all of your configs in one directory, here is a simple script that goes through Cisco configs, parses them and outputs the network id, and netmask. Which in itself isn’t that useful, but now that you have it in a hash, there are a lot of things you can do with it. Like verify it against your routing table or IPAM, etc.. It also does two other simple checks, if the file name does not match the hostname it notifies, and it also checks to see if the interface is shutdown in order to assume it is up.… Read more

Configs Templates Take 2 (17 of 30)

This is the second part of a series of post’s on developing a Config Template tool, click this link to follow the whole series of post’s. This tutorial will go over two attributes of HTML::Template cpan module. The ability to “include” other config templates and the ability to make simple if statements.

Let’s say you have regional configs, in this example, it will be NTP servers, but it could easily be tacacs, radius, syslog, etc… You want to be able to have the user declare one option (the region,) and it correctly declare the regional configs.… Read more