CLUS 2014

Well, another Cisco Live has come and passed. And again, it was a great time with the tweeps (twitter people for the unknowing).


Again this year I was astounded by the huge sense of community and togetherness that comes when geeks let their flags fly. I think the only session I made was the Cisco Champions radio, but that session was so much fun.

Cisco Champions
Cisco Champions

Click here for more about the Cisco Champions

I think what I like best about #CLUS is the ability to have an intelligent conversation almost anywhere. Sitting around the Social Media Routed Bridge, Lunch, Dinner…everywhere.

Wednesday evening comes to mind, where a group of us were sitting in a cigar shop after the CAE, and talked to a voice engineer, CCIE candidate about why he should be on twitter! The best part of this, was when Renee joined in and explained how it helped Aaron study. Growing the community, getting people involved, helping each other, THAT is what it is about!

Or Thursday evening sitting in the lobby of the Hilton talking about SDN and wireless enjoying the “hometown gift” that Scott Morris brought with him.

Getting to meet the greatest people EVAR! like:
Denise Fishburne


Denise Donahue


John Schreiner Capt USMC @jschrein

Carole Reece @cwreese

and many many more.

as well as just hanging around the best people in the world!

Some parting questions. If you didn’t enjoy #CLUS2014, why? What can you do next year to make it more enjoyable?

If you’re not part of the community, why? Why are you not participating, sharing, and growing with the all of us?

Lesson learned? When you need a little bit of luck, kiss a unicorn!

for luck
for luck

Cisco AP Discovery, Option 43/60….And You!

So most of the people that read this blog should know that I’m pretty active on .

One of the things I see there a lot is either a misunderstanding or lack of understanding as to what Option 43 is for.

So, what is Option 43 for? Glad you asked!

Option 43 is one method of WLC discovery. So let me go back a little bit, and lay out how the AP is informed of the WLC.

In no particular order:

Layer 2 (broadcast)
Layer 3
DHCP Option 43/60
OTAP (depricated)
Previously Joined WLC

So, if you have multiple methods, or in the case of Option 43 multiple WLC, which one will it use? Well I’m going to answer you with the standard wireless answer, “It Depends”.

So, what most people do not understand, is that the AP doesn’t just use one method, it uses them all.

Once the AP has “learned” all the WLC it can from all the methods in use, it sends a discovery request to a WLC that it is aware of. In the WLC’s discovery reply it sends the max AP license, as well as the current excess availability for all members of its mobility group.

So what does that mean? It means that if you have 3 WLC 5508.

5508-A is licensed for 100 AP and has 48 currently joined – excess 52
5508-B is licensed for 150 AP and has 50 currently joined – excess 100
5508-C is licensed for 100 AP and has 65 currently joined – excess 35

The new AP should join to 5508-B, as it has the greatest excess availability. Key word here is should. If the AP has already joined a WLC before, this option will supercede all the others. Another caveat is if one of the WLC has enabled. MCM does not have an affect if the AP has a Primary/Secondary/Tertiary set.

Ok, now to go back and explain the methods.

Layer 2, this is purely broadcast messaging. For this to work the AP and WLC need to be in the same subnet, or you have to add a ip forward-protocol 5247 globally, and an ip helper-address under the L3 interface. That being said, this does not really scale well.

Layer 3 AP is not on the same subnet, so we fall to other methods:

DHCP Option 43/60. So Option 60 is ‘optional’, and is a VCI (Vendor Class Identifier). This will limit the server from giving out the Option 43 if configured. While that sounds bad, it’s actually a good thing. If a DHCP request comes in and it doesn’t have the VCI the server will not return Option 43.

Option 43, is the IP address of the management interface. You only need to list one. If you are running your AP DHCP on a IOS switch, you have the ability to list multiple if you so desire.

DNS – CISCO-CAPWAP-CONTROLLER. resolves to the management IP. This option can be nice if you have regional WLC and your DNS broken up, like etc. If you are only then it still works, but you lose the ability to point to a regional WLC.

Now to move on a bit.

You have AP that are already on the network, can you use Option 43 to push the AP to a new WLC? The answer is no. The AP is going to already know all the WLC in the mobility group, so it will first attempt to join the last WLC it was on.

If you need to move an AP from one WLC to another, a discovery method won’t help you. Your best bet is to go through and just set the Primary Controller as the WLC you want it to join, and make sure that AP fallback is enabled.

Cisco Live 2013 aka Geeks in the Swamp


So being my first blog post, cause you know I heard somewhere this was the thing to do between tweets..thanks Amy (@CommsNinja) decided I’d revisit why I didn’t blog in the past, and why I’m going to be doing it in the future. So why is this titled “Cisco Live 2013 aka Geeks in the Swamp”? Well the picture above has a lot of tweeps and bloggers that finally made me rethink, and it’s where I was last week.

The Why I Didn’t

Basically, I could call it laziness and that would be a part of it, but not the whole truth. The biggest reason I didn’t blog was I couldn’t really find anything that “I” found interesting enough to blog about.

Let’s be honest, I work with wireless and oh yes it is definitely an interesting technology. But after ~5 years in TAC there wasn’t a whole lot I haven’t seen, broken, fixed, played with or snarked about. It was multiple conversation at Cisco Live this year, Tom (@networkingnerd) Andrew (@revolutionwifi) Colin (@colinmcnamara) Amy A.(@amyengineer), and way too many others to realistically list here, that made me realize it’s not what “I” find interesting, it’s what I can share to help others grow!! *facepalm* It really is that simple

The Why I Will

There are two main reasons why I decided I should kick off a blog, one is to share knowledge around wireless/BYOD which is kind of a passion of mine, and to help me document my learning of scripting (Python, Puppet etc).

Cisco Live 2013

Let’s call it what it is, Geek-vana! A bunch of really really smart people all getting together to share knowledge, see old and new friends, and let our Geek flags fly.

In years past (2006/2007/2008) I was stuck in TSC (Technical Solutions Center), and last year sitting in session after session. wHile I did learn a good bit during the sessions, this year I took a different tact. This year, it was all about the social aspects of the conference. I spent a vast majority of my time in the Social Media Hub. Chatting with new friends I met on twitter over the year, old friends I met at other events, and listening. Yes, I listened, amazing right!? Funny thing is when I did I heard the same thing. Blog, Bacon, Blog, Cloud, SDN, Blog, Unicorn and Bacon.

But being in the Hub also allowed me to be agile of calendar. I could go to the side meetings and briefings, there were a few where I thought I’d just listen and not have anything to share…turns out that I was incorrect about that.

To sum up, I learned a lot during the breakouts, where the network is going, why Engineers need to learn some scripting, what cloud can do for me, how many others enjoy bacon (really who doesn’t!), and that I should blog.

I call it a net win for the week.

So the long and attention kiddies.