Wednesday, 29 December 2010


Well I have been playing about with GNS3 a little ove the holidays and looking at how it works. I must say that it is user freindly for some things such as routers but other thing, oh boy can it be troublesome.

GNS3 does not natively support switches, ok I think we all knew that. It does however let you add a switch module to your routers and I will be playing with this a little.

Its when you look at GNS3 and what it can do that you really really start to delve deep into it.

I had the pleasure or misfortune of deciding that if I want to look at security later in the year how good would it be to get te ASA working in it.

Well that in and of itself was a challenge but I managed to get it working. OK I still have a minor issue in that I am unable to save my configs but from a lab perspective thats no big deal as all it really means is having to type everything in again and again. Well hey thats what i would do anyway so I can cope with that. I could also save the configs to a text file.

I also dont have it working in multiple context at the moment but hey little steps. Considering I have no experience currently just getting used to setting one up will be a big step.

Then however I decided to get ASDM working, that was not too hard but you rereally need it working as thats the straight forward way to setup an ASA. Well I managed to get it working at last, the trick there is to use Fiddler but as it intercepts we traffic and sends it to the ASA it screws up your ability to browse the internet.

OK at the end of the day I can practice on it and get some use but I will still probably but and ASA.

Before anyone asks I will not be doing a write up of how to install it ananytime soon. Firstly I want to get all the gremlins sorted, seconly I have other things to focus on, thirdly I really like cables and devices so will practice on a real ASA when the time comes, ASA in GNS3 is a nice to have but GNS3 is really for routers in my humble opinion.

Just a cautionary note, there is an aweful lot of stuff on the internet about getting ASA to work in GNS3, much of it is absolute bollocks I am afraid to say, its pretty straight forward if you have the right stuff as I found out but I still have gremlins. Have fun sorting out the wheat from the chaff.

Here is a link to help you get started ASA on GNS3

Thursday, 23 December 2010

CSCth51156 - Extracting Custom Web Authentication Tar Package May Fail on 5500 WLC

Well I came across a bug that really threw me, basically all those years making tar files and now I had to find a Unix tool to do it. I didn’t use gnuwin32 as it was a nightmare to find and install but Cygwin was awesome, loaded staright away and had my head around it in about 30 minutes.

Also you need to purchase PowerArchiver which I always hate buying software when there are free options available.

When running WLC code on a 5508 WLC, the tar extraction process may fail generating the following error:

Error extracting webauth files.

This condition only occurs on a 5508 running the code. The same
package can be loaded on a 4404 running successfully, and also to a 5508 running

Create .tar package using the following command on UNIX or Windows (via
tar -cvf login.tar < file1> < file2> < file#>...

PowerArchiver 2010 for Windows (GUI) - Package as Tar, Store

Sunday, 12 December 2010

CCNP Route

Well blogging has taken a bit of a back sat over recent months as I have been really busy with work. However now there is a little hiatus its back to studying.

I was really lucky to be invited onto a Cisco CCNP Route Beta course delivered over the web which was interesting. first the course content was excellent as was the presenter. However it was difficult to stay focused on a webinar for 8 hours a day over 5 days.

That said it certainly filled some knowledge gaps and gave me an understanding of all the content.

Some of the ROUTE content terified me, notably BGP and OSPF which is not good as thats half the course. However I feel alot more confident now that I have some knowledge to build on and neither looks too scary. That said I have a lot to learn.

As well as hopefully posting a bit more on wireless which is my first love I will also post on my CCNP endeavours which will help me memorise the various parts.

For studying I have my lab and GNS3 and will be using some Trainsignal vidos along with Odoms CCNP ROUTE book and the CCNP ROUTE Lab book. I hope thats enough to see me through!

Time scales, well thats a hard question to answer but I am giving myself 6 weeks of hard study to get to grips with it and then review where I am upto. Starting off listening to all the videos and reading the book while doing some labs to aid understanding. Then just lots of labs and back to the videos before the exam.

Friday, 19 November 2010

Juniper to buy Trapeze - Official

Earlier this week Juniper announced it is to buy Trapeze Networks. Below is a link to the announcement.

I am sure this can only be good news for Trapeze, juniper and the wireless industry as a whole.

Friday, 12 November 2010

Whats next?

Well over the last few months some of the things I have wanted to study have been on the back burner as I was really struggling wiith the CCDA, now thats out of the way I can focus on a few things.

I have to take my CCNP R&S for career developement which is fine, just do not want to tackle another design exam. I struggle with business goals, technical goals etc and how they differ from constraints, sometimes the differences are subtle. The CCNP wil be a milestone, the ROUTE xam is the one I will struggle with most bu I have done a littel studying and its actually making sense.

My wireless exams I will get though as time permits as there are quite a few of them. CWNA, CWSP and the two new exams from the good people at CWNP and also the CCNP Wireless.

The CCNP R&S is going to take up much of my study time and I will be labbing alot, the CCNP Wireless I should be able to get through pretty easily. The CWNP exams well I think they are a different level as they test your understanding of the core concepts rather than deployment so I have to make sure my concepts are solid. Good thing is I know where I need to focus and I understand all of the wireless stuff unlike the CCNP R&S some of which has me scratching my head.

All in all i have about 12 or 13 exams to do, will it be worth it in the end? Well I guess I can only answer that later when I am getting towards my goals. At the end of the day its a journey not a destination.


Well after last week taking the CCDA I sat the AWLANSE today and passed. I didn't want to take it on the same day as my CCDA as I was under so much pressure with the CCDA it was untrue.

The exam was not hard but alot of the questions were a little dated, nothing at all on 802.11n and quite a bite on the WLSE, which I have only seen two of and do not like working with.

All in all a fair test but if you don't read wireless guff as a hobby, particularly Cisco it will be a struggle to study for as there is no real training material apart from the Cisco course.

Quite a few of the questions had me scratching my head and there were a lot of questions for a 75 minute exam. It was either know it or guess and move on.

Passing this also achieves a career milestone for me which I am really pleased about.

Friday, 5 November 2010

Passed CCDA

I have finaly passed my CCDA, not sure how to descrbe it as I was so worried perhaps I over prepared.

I studied for about 3 months, hence no blogging, and thought I wasn't ready but had to sit it anyway as the syllabus is changing thought "what the hell" and went for it.

Well I went along and did quite well in all areas.

It is a tough exam don't get me wrong but this is the one I have been avoiding for so long it has held me back in other areas.

Now its AWLANSE next week and a proper start on my CCNP and CCNP Wireless.

Just so glad that hurdle is over as it is well outside my comfort zone.

Tuesday, 13 July 2010

Lab update

I have taken delivery of an AIR-WLC4402-12-K9 from my great freind George Stafanck. This will allow me to get a lot more practice with senarios using the later code versions, my existing controller is an AIR-WLC2006-K9 which will not run later codes.

The main advantage of the 4402 is being able to setup guest access in a DMZ which I could never test with the 2006. Obviously there is additional functionality from the later codes.

I still want to add another controller but that will probably be a 2106 or a newer variant thereof if one is released soon, however the code would not be downgradeable to 4.2 which is the CCIE Wireless code.

Its very much a can of worms as there is a strong rumour that the CCIE Wireless will change next year which will mean a code change so its difficult to know what to add.

Anyway thats a brief update, however I am extremely busy at work at the present time so do not have a great deal of time to lab but will hope to get some time this weekend to test a few things out.

I need to start running scenrios more with Windows 2008 and take a serious look at ACS 5.1 as apparently its very different. Always a challenge I guess.

I will post a few lab pics later in the week.

Monday, 12 July 2010

All you need to know about wireless - Einstein

You see, wireless is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is there is no cat.

—Albert Einstein

If its on the exam you can have my house

Monday, 21 June 2010

Cisco WLC Software Advisory

Software Advisory – Wireless LAN Controller Software

Base Code:,,

Platforms: 2100 / 4400 / 5500 / WiSM / WLC3750 / WLCM

This Software Advisory Notice is issued against all the above Wireless LAN Controller software versions due to the following bugs:

CSCtf34858 Client can't transmit traffic if it reassociates to an AP within 20 sec

CSCte89891 Radio may stop transmitting beacons periodically

Special Build: Following options are available:

1. Move to Release posted on CCO. Please note, 7.0 is a new feature release.

2. Contact TAC to get a 6.0 Special or Beta release with fixes for the bugs below.

3. Wait for the CCO release of 6.0 MR3 (Maintenance Release), which is planned for July/August 2010

Friday, 11 June 2010

CCNP Wireless eBooks available

Great news Cisco Press has released the first two of a series of four CIINP Wireless Quick Reference Guides.

The 642-736 CCNP Wireless IAUWS Quick Reference eBook (Implementing Advanced Cisco Unified Wireless Security) written by William G. Daniel priced at $24.99.

The 642-746 CCNP Wireless IUWMS Quick Reference eBook (Implementing Cisco Unified Wireless Mobility Services) written by Jerome Henry priced at $24.99.

The other two publications in this series are scheduled for release on 20th August these are as follows

The 642-741 CCNP Wireless IUWVN Quick Reference eBook (Implementing Cisco Unified Wireless Voice Networks ) written by Jeffrey DiMaio.

The 642-731 CCNP Wireless CUWSS Quick Reference eBook (Conducting Cisco Unified Wireless Site Survey ) written by Jerome Henry.

Wednesday, 9 June 2010

iPhone fubar video

If you want to see how wireless doesn't work take a look at Steve Jobs.

I can't imagine how much he was cringing!!!

Tuesday, 8 June 2010

Shiny Shiny iPad

Well as I posted a while ago I was one of the winners of the CWSP competition. I am glad it was then and not now as I have been busy. However I did win the iPad and much to my disappointment and a few circumstances beyond my control I have not had the time to get right into it, however thats about to change.

I will be setting the iPad up properly tomorrow, my usage will be mainly for reading and studying, usually in bed as its much easier to lie back with the iPad than a laptop so I have to get a pdf reader on it and download some material. Shouldn't be too hard but everything has to go through iTunes which I was not a fan of, maybe thats changed, we shall see.

My first impressions though were great, out of the box it connected straight away to my secure wireless network, I haven't tried it with PEAP or other higher level security yet but I am sure I will.

Surfing the web is easy if a little clunky when you are used to tabbed browsing, maybe theres and app for that.

I liked the quality of the screen, very clear and bright even thoug a little small its a good size to pick up and read from. Zoom capability is great and really responsive.

All in all I am quite pleased and will be making use of it, target to get some material loaded onto it tomorrow and look at other apps in due course.

Standards Update 802.11n Download

By far the most important change to wireless ever the 802.11n standard is now available for free download.

As from my previous blog I gave details of all the wireless standards that are freely available this should certainly be added to your collection.

It can be downloaded here

For the other standards here is a link to my previous post which is updated with the 802.11n standard


Well its been a while since I blogged as I have been busy, you know how it is, you always need to focus on other things.

Well I also need to focus on my blog or it will surely die and maybe I am going to change the way I do things a little.

Instead of summarising chapters I read I am going to try to highlight the things I learn.

I have read afew more chapters of the CWNA book and although I probably know quite a lot of the information its interesting to find out what you do not know. More about that tomorrow though.

There is also the work life balance, I lock myself upstairs in the office and nobody bothers me which is great but then I have to exercise my dogs, and get more exercise myself. Currently trying to shed a few pounds and cycle more in the good weather.

I have also reassessed a few things and timelines for certs etc and I have decorating to do so busy life, thats besides having to do all the work stuff and personal admin like banks etc.

There simply are not enough hours in the day so I will have to change they way I blog a little.

It will still be about wirless and wireless related but if we take the CWNA blogs as an example maybe not as much detail.

I am just finishing chapter 5 of the CWNA so will write more tomorrow on that but I also need to get reading the CWSP aswell if I want to take advantage af my package.

I also need to tell you about my shiny shiny new iPad that I won from CWNP and get that all up and running.

So lots to tell just keeping it a little simpler.

Monday, 7 June 2010

New iPhone launch hampered by wireless congestion!

The launch of the latest iPhone was hampered by wireless congestion.

Apparently when Steve Jobs went to demo the screen resolution he could not connect to the wireles network as it was oversubscribed by the 570 media present all blogging and tweeting away happily.

You couldn't make this up!

Read more

Cisco Code Version 7

Cisco is posting code version 7.0 for its wireless controllers and associated wireless solution components. I haven't ad a chance to look at it yet as its a brand new code so my recomendation would be to check out the release notes and test before deployment.


Configuration Guide

Command Reference Guide

Controller Release Notes 7.0

WCS Configuration Guide 7.0

WCS Release Notes 7.0


MSE CAP Configuration Guide

MSE wIPS Configuration Guide

MSE Release Notes 7.0

Spectrum Expert 4.0

SE User Guide

SE Release Notes


Mesh Deployment Guide


Navigator Release Notes

Saturday, 15 May 2010


Ok well here it is a shameless plea for help.

I am obviously interested in wireless and will be targeting CCIE next year so I need to improve my lab.

Is there anyone out there with a Cisco AIR-WLC4402-12-K9 that is just gathering dust. Now donating it would be great but I have some funds to purchase but they are all a bit pricey on eBay.

Equally any other wireless hardware that people want to donate to a good home will be appreciated and loved.

Key things I have to get are a spectrum analyser, looking at actually getting a WiSpy usb, also any spare access points considered.

All enquiries or offers can be emailed diect to me at

There has to be someone out there with a low cost 4402?

Google Boobs again!!!!!!

Well well well who would have thought it!

Google after many accusations of spying, infringing peoples privacy and controversy over mapping wi-fi networks with their Street View program have come clean and admitted collecting information sent over wireless networks.

Well I personally think that they now have a lot to answer for, after all its quite difficult to do accidentally, mapping wi-fi networks would be an entirely different process than authenticating to the networks and downloading data. In my view its at the very least very poor project management and obviously a complete lack of knowledge about what they were doing, at the worst its spying and theft of data.

To turn around after three years and say we didn't know well I'm sorry Google I don't believe you. You have been caught with your pants down, hand in the cookie jar, however you want to call it.

I doubt it will go legal but who the hell is monitoring these people.

Read more here

Wi-fi owner fined for lax security in Germany

Well it looks like big brother is clamping down, the unfortunate owner of a wi-fi network in Germany has been fined €100 by a German court because his network was not secured and a third party downloaded copyright material from it.

Personally as its a technical product and not everyone is tech savvy I feel it should be the service provider or the manufacturer that has the responsibility to ensure adequate security to meet legal obligations for domestic products ie anything sold to the public or provided as part of their broadband service. I know most service providers routers are secured these days but it doesn't go far enough with the compromises that are out there. Enterprise products are entirely different as you expect them to be installed by a technically competent person.

Read more here

Thursday, 13 May 2010

Free Books

Where do I start, lets just say I am very suprised by Pearson Education.

You see they have a book review program and I got to find out about it and asked if I could review a few books that were coming out hoping I could get a seaky peak at a few wireless books as there are some new ones out this year.

Well I got an eamail with a list of books, non wireless but certainly a few that I was interested in. I replied to them saying which books I was genuinely very interested in and a week or so later took delivery.

Awesome scheme.

I spend quite a lot on books, study materials, hardware and exams so was really impressed.

Well as I said after a little email ping pong I now have a copy of "Securing the Bordeless Network" by Tom Gillis.

Initial thoughts are it looks good and I will certainly learn a few things but I have to review it so I am busily reading through it.

But hey, what a great scheme.

Tuesday, 11 May 2010

WLC Discovery Process

The LWAPP or from code version 5.2 CAPWAP discovery processes vary slightly

The general process is as follows

1 Layer 2 broadcast which isnt much use as it was only supported on the 1000 series access points.

2 Layer 3 broadcast

As this is blocked by the router and the IP helper-address only forwards directed broadcasts, unicasts and 8 UDP ports by default. These are TFTP port 69, DNS port 53, time protocol port 37, netbios name server port 137, netbios datagram server port 138, BOOTP client and server ports 67 and 68, TACACS service port 49.

Therefore you need to explicitly allow prt 12223 LWAPP data protocol and or port 5247 CAPWAP data protocol

Router(config)#interface fa y
Router(config-if)#ip helper-address x.x.x.x
Router(config)ip forward-protocol udp 12223

3 OTAP which should only be used in commissioning as it is/was a security risk now deprecated it was part of the RRM. It is now deprecated since code 6.0 and RRM is encrypted.

4 Locally stored controller IP address

5 DHCP option 43 is used to return the WLC IP address and is vendor specific. This is the IOS command for option 43

ip dhcp pool

Option 43 hex

DHCP can be set on the switch,router or via a DHCP server.

Along with option 43 you can have option 60 which is the vendor class identifier and says only return option 43 if you are sending an ip address to a client that needs it like an access point and loooks like this in IOS.

option 60 ascii "VCI string of the AP"

This shouldn't matter in an enterprise as your aps should be on their own subnet however its handy as thats not always the case and it prevents clients getting uneccessary information.

Options 241 and 120 are not exactly options but sub options and define how the IP address is sent. for everything but the Cisco 1000 series this is 241 which is hex. For the 1000 series its 120 which is ASCII.

6 DNS , configure DNS to returm the controller IP address to a query for CISCO-LWAPP-CONTROLLER@localdomain, also if you are running code 5.2 or above it helps to use CISC-CAPWAP-CONTROLLER@localdomain.

Generally after priming access points I always implement DHCP option 43 and DNS in enterprise deployments as you pretty much know that th access points will home to a controlller when and if they upscale add or replace access points.

The reason for priming is that you can asign ap names, ip addresses and WLC addresses and designate where the access point is to be deployed rather than ending up with hundreds of access points pulling down ip addresses and not knowing where they are.

CWNP Winners

The good guys at CWNP have ben running a competition the last about 6-8 weeks with prizes of CWNP Self Study Kit, CWNP Study Guides and a 32GB iPad.
Well the competition is over and the results are in.

I managed to get drawn out of the hat for the iPad which is brilliant news, no excuses for not stuying now!! I also managed to win a CWNP Self Study Kit which will have to be the CWSP which has an exam voucher with a free retake should you fail. The voucher never expires but the free retake is valid as on offer till the and of August. With the iPad and the Study kit thats well over £500. Brilliant.

You can see the other prizes and who the prize winners were here on the CWNP Forums

Just leaves me to say thanks to CWNP and congratulations to all those that took part.

Aruba Networks buy Azalea Networks

Aruba today annonced the acquisition of Azalea Mesh Networks.

Use the link below to read the press release

Good Luck

I am just taking this opportunity to wish two people I know, hopefully they won't mind me calling them freinds, the very best of luck for their CCIE Labs which they are taking.

Both have been working extremely hard in their respective studies and I admire them both greatly. They both deserve it and I am sure they will be successful.

Gabriel Bryson is taking the CCIE Security Lab on Wednesday 12th May 2010 and Jennifer Huber is taking the CCIE Wireless Lab on Tbhursday 13th May 2010.

Good luch to you both.

Thursday, 6 May 2010

No more CCIE OEQs

Well it looks like the end of Cisco's controvertial OEQs which have been a part of the CCIE track for about a year.

Some of the CCIE tracks having them added recently and others still waiting. However the news is that they will be gone as of the 10th of May from the R&S and Voice tracks. Surely its only a matter of time before they go completely.

I haven't seen anything official yet but thats the rumour.

I think there is enough pressure without them for CCIE candidates. Imagine you pay $1400 for the chance to take the exam and can fail in the first 30 minutes on the OEQs.

The written should be weeding out those that aren't upto the exam.

The CCIE lab has always been about hands on, it's the 800lb gorilla of the tech exam world.

I know that those who have failed the OEQs but aced the configuration and troubleshooting may not get much flexibility from Cisco, I can't see them saying "Oh well OK so it was a bad idea here's your CCIE as you aced the config part" but thats life.

It was always wrong when Cisco introduced two classes of CCIE the haves and the have nots. That the 360 candidates got the waiver was the thin end of the wedge but hail hail it looks like common sense has prevailed and maybe just maybe for once Cisco has listened to the communnity and relented. There are a lot of good ideas in the Cisco community and most Cisco certification candidates do it the right way, study hard and put in the hours. To fail the CCIE on 4 or 5 questions would heart breaking.

Well done Cisco, good move.

No doubt there will be other tweaks to the exam with that half hour slot to fill but its definitely a good move.

Tuesday, 4 May 2010

Access Server Config

It may not appear to be the hardest thing in the world but as I said in a previous post when I had the NM-16A/S in the 2613 router it wasn't working, I had all sort of intermittent issus and evn reterminated a few of the octal cablle ends that took some time. After swapping the NM-16A/S to a 2610 all was well so I could configure the access server.

Its actually amazingly straight forward, here is the config.

Current configuration : 828 bytes
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
hostname TermSrv
no aaa new-model
resource policy
ip subnet-zero
ip cef
no ip dhcp use vrf connected
no ip ips deny-action ips-interface
ip host R1 2033
ip host R2 2034
ip host R3 2035
ip host R4 2036
ip host R5 2037
interface Loopback0
ip address
interface Ethernet0/0
no ip address
ip classless
no ip http server
no ip http secure-server
line con 0
exec-timeout 0 0
logging synchronous
line 33 40
no exec
transport input all
line 41 48
line aux 0
line vty 0 4
password cisco

Another issue I had was looking for ports 1-32 which are taken up by module 0 and I was plugging into module 1, I know, with the issues I was having and expecting the access server to work first time you panic and think there is an issue. Note that it is a 2610 and only has 1 module slot, I assume that module 0 is taken up by the WIC slots. However, you always learn more if it doesn't work as you expect first time than if it does work.

Nice Rack!!!!

Yeah thought that might get some attention!

Well here is a photo of my rack that will see me through my CCNP and beyond. Its nearly all my own gear and even though its in a nice Skeletek rack and to me looks great my better half won't let me have it in the lounge.

And here are my access points

Anyway here is the run down

3 x Cisco 2620XM routers each with a pair of WIC-1Ts installed
2 x Cisco 2610XM routers each with a single WIC-1T
1 x Cisco 2610 router with a single WIC-1T
1 x Cisco 2610 router with an NM-16A/S used as a terminal server
1 x Cisco 2613 router, yes it has a token ring port.
1 x Cisco 1841 router with a pair of WIC-2Ts, I need to buy cables.
2 x 2501
1 x 2522 FR switch
1 x 2521

3 x Cisco 3550 EMI switches
1 x Cisco 3560-8 EMI for poe for the access points.b

1 x Cisco 2006 WLC
3 x Cisco 1242AG access points
2 x Cisco 1230 access points
1 x Cisco 1131AG access point
1 x Cisco 1252 access point

1 x Dell GX620 4GB of RAM
1 x Dell Poweredge 1800 Dual Xeon 3.2GHz 4GB of RAM running VMWare ESXi4.0

Running in VMWare ESX4.0 I have a small test domain with Windows Server 2003 and 2008 to familiarise myself with IAS and NPS. I also run Cisco WCS and ACS.

Running in VMWare ESX3.5 I Cisco Guest NAC appliance and Cisco MSE.

What do I want to add? Well thats the $64000 question.

I am buying a Cisco WLC 4402 this week.

Another Cisco 1841 router would be nice.

There will be an ASA 5505 going in.

A pair of Cisco 3560 switches would be real nice.

Studying CCNP

I am one of those people who gets the most out of actually getting something to work, and usually breaking it in the process, then fixing it to develope an understanding.

Now I have the CCNP BSCI Lab Portfolio book and the new CCNP ROUTE book, my intention is to flash through a few labs and see where I get and then go back and start reading the concepts. I know this might sound a little strange but I am hoping I will understand some of the commands and start to see how each routing protocol interacts and build on a foundation.

For the ROUTE exam I have a lot to learn as I only know the basics of routing from CCNA and there will be an awful lot to learn, I have given myself about two months or so. The really scary part will be BGP as it looks huge. I have chosen the new path as it has dropped a few topics which I may pick up at a later date such as MPLS, QoS and Multicast, however thse are all subject matter for the CCIP, I just can't see myself doing that but MPLS is becoming more and more important.

As for the Switch exam I understand most of the concepts and have implemented quite a lot of the technologies, trunking, etherchannel, layer 3 switching, high availability, the majority I have experience of however it is all the variables that will pose the issues such as LACP and PAgP. Spanning tree and ACLs will need practicing alot.

TSHOOT should not be an issue if I have studied each topic extensively, or am I deluding myself, we shall see.

All of this while looking for a gew quick wins on the wireless side so I may be challenged over the summer and miss some important world cup fixtures.

I intend to work to the posted exam objectives which I have put into a matrix where I will score myself on my knowledge level, 0 being I do't even know what that means and 5 being I am an expert and know it cold. I will post the patrix on the site so if you want to see my progress you can check on it. At the start thee may be some errors where I think I know something and give myself a 3 and downgrade that but when its all 3-5 I will be taking the exam, also it will depend on my comfort at the cli.

Wish me luck!!

Monday, 3 May 2010

CWNA Study Guide Chapter 2 Radio Frequency Fundamentals Key Learning Points - Part 2


As RF waves travel they encounter various media tha affect them in different ways, these medi include air, water, trees, walls etc. Anything that the RF waves encounter may affect the way the waves behave.

These RF propogation behaviours inclued absorption, reflection, refraction, scattering, diffraction, free space path loss, multipath, attenuation and gain.

The way RF waves move, propogate, as it moves away from the antenna can vary dramatically depending on what is in its path.

Different materials, combinations of materials or events can have significantly different effects on a signals charcteristics.


Absorption is a fundamental property of RF waves, different media will absorb more or less RF and attenuate a signal to a greater or lesser degree. For example concrete walls will generally have a highe absorption tan glass therefore greater attenuation.


RF waves will bounce off, reflect from, surfaces that are smooth. If the object is larger than the wave itself the wave will reflect, therefore reflection is dependent on frequency. Different object reflect different wavelengths to different degrees. Filing cabinets, doors erc can reflect RF wave sin the Wi-Fi spectrum, the angle of reflection depends on the angle of incidence.

Reflection can degrade signal strength and cause signal attenuation and data corruption. Hardware strategies help to overcome overcome these problems with directional antennas or antenna diversity.

Multiple reflected signals cause an effect known as multipath. MIMO antenna technologies actually take advantage of multipah.


Two types of scattering may occur the first type has a lesser effect on the RF wave and is caused when the wave travels through a medium containing minute particles like fog. The second type is when an RF wave hits an uneven surface and is reflected in many directions, foliage and rocky terain may cause this type of scattering.


refraction occurs when an RF wave travels through mediums of different density that cause the direction of the wave to change. Generally this is encountered over long distance outdoor bridge links where water vapour and changes in air pressure and temmperature may cause this effect.

The k factor is a unit of refractivity index in long distance bridge links. A k factor of 1 means no bending, a k factor less tahn 1 represents a signal bending away from earth. Normal atmospheric conditions have a k factorof 4/3 wic is bending sligtly towards te earth.


This is where an RF wave bends around an object and should not be confused with refraction. This would typically be some kind of obstruction. A dead zone may exist immediately behing the obstruction known as an RF shadow.


Loss or attenuation is the decrease in amplitude or signal strength. Loss may occur on the wire due to impedance of the cable or in the air due to absorption and distance. Different materials have different absorption properties.

Loss and gain may be gauged by a relative measurement of the change in pwer called dB.


Free space path loss (FSPL) is the attenuation of the signal due to the natural phenomenon of the signal spreading out over a larger area as the signal moves farther away from the antenna. Loss in signal strength is logarithmic and not linear therefore a signals strength does not decrease as muchin subsequent segments of equal distance as in the segment.

A 2.4 GHz signal will attenuate by approximately 80dB in the first 100m from the antenna source and only 6dB in the second 100m from the antenna source.

FSPL = 36.6 + (20log10(ƒ)) + (20log10(D))

where FSPL=free space path loss, ƒ=frequency and D= distance in miles.

FSPL = 32.44 + (20log10(ƒ)) + (20log10(D))

where FSPL=free space path loss, ƒ=frequency and D= distance in kilometres.

This can be described as the 6dB rule in that for every doubling of the distance te in loss of amp;itude will be 6dB.


Multipath is the propagation phenomenon that results in radio signals reaching the receiving antenna by two or more paths. Causes of multipat are scattering, refraction, difraction and reflection. Typically reflection is the main cause of multipath.

The reflected signals will arrive at the receiving antenna nanoseconds after the priniciple signal due to travelling further, this time difference is knwn as delay spread.

The results of multipath may either be good or bad. generally the results are destructive due to the differences in phase of the multiple paths. The combined signal may attenuate, amplify or be corrupted.

The four possible results of multipath are

Downfade is decreased signal strength caused when the received signal arrives at the receiver at the same time as the principle signal but are out of phase by between 121 and 179 degrees.

Upfade is increased signal strength caused when the received signal arrives at the receiver at the same time as the principle signal and is in phase or nearly phase. The phase differences are between 0 and 120 degrees. The received signal can never be stronger than the transmitted signal due to free space path loss.

Nulling is the complete cancellation of the signal caused when the received signal arrives at the receiver at the same time as the principle signal but are out of phase by 180 degrees.

Data corruption can occur due to the differences in time between the reflected signals and the principle signal. The delay spread time differential may cause overlapping and the receiver may have problems demodulating the signal.

Multipath may be problematic causing layer 2 retransmissions and negatively impacting the WLAN throughput.

Direction antennas and antenna diversity may help reduce multipath problems.


Gain is the increase in amplitude and there are two types of gain, active and passive.

Active gain is the use of an amplifier on the wire and generally requies an external power source.

Passive gain is the focussing of the RF signal by use of an antenna.


Frequency Domain Tool - spectrum analyser

Time Domain Tool - oscilloscope

Sunday, 2 May 2010

CWNP Exam Offer

The good guys at CWNP are offering free exam retakes if you should happen to fail your first attempt.

If you buy an exam voucher from CWNP for either the CWNT (PW0-070), CWNA (PW0-104) or the CWSP (PW0-204) and are unfortunate enough not to pass they will let you resit the exam for free between 1st May 2010 and 30th August 2010.

I've never been in the right place at the right time to take advantage of similar offers from other vendors and I don't know if CWNP have done this before but its a great idea especially with the cost of exams these days. Also generally if you don't manage to pass first time round you want to get straight back in the saddle and try agian, obviously after a little revision of those weak areas that prevented the pass in the first place.

As I am currently studying I will certainly take advantage and set my goals to have a crack at the exam before the end of August.

More details are available here

I think these offers are great as it gives you that little bit of peace of mind as well as investment protection as non of us like throwing money away and most of us are self funding certifications these days.

They also have some great deals on their certification packages at the present time so go along and check out the CWNP Store

Saturday, 1 May 2010


Well tomorrow I intend to start studying my CCNP, I have been trying to get a little bit done all week but have been quite busy in work.

I went up to my lab a few nights ago and decided to setup the access server just to be ready, unfortunately it took alot longer than I anticipated as the Cisco 2612 that I was intending to use with an NM-16A/S just didn't want to play properly. One minute I had a connection from the access server to a router next it was gone when I went to check the cable moved and I got connectivity so you naturally think faulty connector but there was no consistency, I cut one of the ends off the octal cable and remade it but it didn't fix the issue.

Finally I took the NM-16A/S out of the Cisco 2612 and put it in a Cisco 2610, cut and pasted the configuration into the cli and kerching!!! Everything worked sweet as can be. Wasted hours but learned a great deal about setting up access servers which is actually really easy. However I had wasted  too much tome and that was that.

I intend to go through the CCNP ROUTE book cover to cover and lab up as much as I can. I will also use some videos, Cisco PEC and I bought the CCNP BSCI Lab Portfolio.

I will be starting EIGRP tomorrow and as routing is my weakest area of the CCNP it will be a struggle to get my CCNP ROUTE. I know I can do it but its if I can do it as quickly as I want to so I can get on with wireless study.

This will obviously distract me from my wireless studies but I will fit some in during my CCNP R&S studies. However I am committed to getting the CWNA aswell in the next few months so it will all be fun.

Friday, 30 April 2010

CWNA Study Guide Chapter 2 Radio Frequency Fundamentals Key Learning Points - Part 1

I thought this chapter was probably the most important as a fundamental target to knowing how wireless interacts with its environment, what may affect a radio wave and how it may perform.

Understand what a radio wave is including the electromahnetic spectrum and radiation types such as radio, light, x-ray etc

To produce a radio wave an ac current (alternating current passes through an antenna producing a signal. ac current has a  typically sinusoidal waveform as oposed to dc current which is linear at a fixed amplitude.

The signal generated by the antenna is dependent on the changes in the ac current properties.

Properties of the ac current that may vary are wavelength, frequency, amplitude, phase and polarity.

Electromagnetic waves can travel through objects.

In a vaccuum RF travels a the speed of light which is approximately 300,000 km per second or 186,000 miles per second.

When a wave is generated it moves away from the antenna, it is said to propogate.

When a wave propogates and comes into contact with objects it can change, these changes are propogation  behaviours, these include absorption, reflection, refraction, scattering, diffraction, loss, free space path loss and multipath,

Understand RF characteristics and the relationship between wavelength and frequency. There is an inverse relationship between wavelength and frequency.


where λ=wavelenth, ƒ=frequency, c=speed of light

Simple transposition of the above formula can prove the following

The higher the frequency the shorter the wavelength.

The longer the wavelength the lower the frequency.

Typical wavelengths in the 802.11 RF spectrum are

2.4 GHz = 12.5cm or 4.8"

5.0 GHz = 6.25 cm or 2.46"

A wave will attenuate or lose signal strength as it apsses through a medium, a signal with a higher wavelength and therefore a higher frequency will attenuate more for a given medium. An RF wave may attanuate to such a degree that it is below the receive sensitivity of the receiving radio and cannot be demodulated successfully and has become unuseable.

Theoretically a radio wave will travel forever in a vaccuuum.

Coverage distance of a radio wave is dependent on attenuation, brick, glass, water and even air will attanuate an RF signal.

Attenuation in air is called free space path loss.

2.4 GHz radio waves will propogate better than 5.0 GHz radio waves.

Frequenccy is the number of times an event occurs in specified time, in RF it is measured in Hertz which is cycles per second. 2.4GHz is 2.4 billion cycles per second.

Amplitude can be seen as the power or strength of a wave and when you look at an oscilloscope you would see the height of the wave vary with a change in amplitude.

Phase is the reltionship between two or more waves that share the same frequency. Phase can be measured in distance, time or more usually degrees. If two waves are in alignment they are said to be in phase. Phase is imprtant as signal amplitude may increase or decrease dependent on the phase relationship and is known as multipath

CCNA Wireless Experience

I took the CCNA Wireless exam and passed thankfully about two weeks ago, before I started blogging, I would have been gutted to get a fail with my experience and would have probably quickly resat the exam and kept quiet!

I think the exam was fair however you either needexperience or alot of reading as there are just some questions that you would find it hard to pick up.

Look at all the practice questions from Boson and on the Cisco site and it will give you a good idea what to expect. The harder part for me was definitely on the 500 series controller as I have only configured one and its alot different to the enterprise controllers so had to read some on the 500 series. Being intimately familiar with the enterprise models, the 4400 and 2100 series, I automatically think about what I would do if deploying them. Know the limitations of the 500 series access points and controllers. Also get some hands on even if its just a sandalone access point.

I studied for about a week pretty solidly but was involved in the Cisco CCNA Wireless Study Group quite actively that has helped me get into study mode and probably think more aboute the minutae that would be on the exam rather than just being able to configure and understand the processes. At the time I was on there I was studying for my CCDA, I still am, I should be sitting the CCDA tomorrow but have delayed it for about a week.

All in all I thought it was a pretty straight forward test and a fair assessment of what you could expect at that level.

I did however give myself quite a bit of stress as I also sat the Cisco AWLANFE exam on the same day, thats the Advanced Wrireless Field Engineer 642-631. I thought the material would be pretty similar and to a large degree it is. The only issue I had was time and a few of the less familiar topics like EAP-FAST that I had to read up on. The main issue is that it is based on older code so you have to think in terms of code 4.0 and also know the 1000 series access points.

Finally sitting two Cisco exams in one day is stressful even if you know the sbject matter. I have pledged to do the same for my CCDA and AWLANSE, thats the 642-681, but I know it will be a lot tougher than the CCNA and AWLANFE. Most people I spoke with thought I was mad even attempting it. I onestly can't see myself doing the same for my CCNP Wireless, R&S or teh CWNO stuff, the detail and depth is so much harder and alot of the routing stuff will be new though the concepts are alot more meaningful now and are actually making sense.

Tuesday, 27 April 2010

New Access Points and Code from Cisco

Cisco have just launched several new and exciting products to to enhance and extend their existing wireless portfolio.

First off is the 3500 series access point available in a variety of flavours. Theres the 3500i wth integrated 4.0 dBi antennas on the 2.4 GHz radios and 3.0 dBi on the 5.0 GHz radio. There is also a 3500e for more challenging environments supporting external antennas. Each available as single or dual band.

The key feature though is the Cisco's CleanAir Technology which makes this the industry's first 802.11n access points to create a self-healing, self-optimizing wireless network.

There is also a new isco 1260 series access point which very much looks like a replacement for the 1250. A major advantage being that it can be powered with standard 802.3af PoE. This is designed for indoor challenging environments with external antennas.

Finally there is the announcement of Cico Unified Wireless Network Software Release 7.0, hooray, well for me anyway as I hope there are one or two resolved caveat so I can get a few upgrades done.

I will get a little more time later in the week for a better update and include some details on CleanAir Technology and feature enhancements in Cisco Unified Wireless Network Software Release 7.0

Monday, 26 April 2010

CWNA or Bust

Those of who love wireless will no doubt be aware of the CWNP or Bust competition which offered a great opportunity to win some great resources to complete the CWNA or CWSP certification tracks.

The competition was hosted by George Stefanick of my80211 and sposored by the kind people of CWNP.

The winners were announced a few days ago and are posted here on my80211.

I just want to say congratulations to the guys and wish them luck on their exciting journey.

I have got to know two of them reasonably well trough forums and will be following their exploits religiously. They each have to blog their activities weekly and I know they are keen as mustard to get started.

Congratulations to John Bogard, Rick Todd and Darby Weaver. Their blogs can be followed via these links.

John Bogard

Darby Weaver

Rick Todd

George Stefanick

Faster than 802.11n meet 802.11ac

Just as you thought you could breath a little easier in this fast paced wireless world that we live in there's a new kid on the block, well a new standard in the making and it will be here sooner than you think. Yes another new standard.

I can recall when I got my first 802.11g access points and panic set in about compatibility with the 802.11b we already had installed. I needn't have worried but I was still a novice. I didn't even know at that time about 802.11 or 802.11a.

A little history, the 802.11 standard was minted in 1997 provisioning 1 Mbps and 2 Mbps in the 2.4 GHz spectrum, I know it seems along time ago but it had a decent uptake in manufacturing and warehousing. Only 2 years later 802.11b and 802.11a came along, that’s 1999. 802.11a provisioned up to 54 Mbps but was slow to capture the market due to generic client support. 802.11b on the other hand took off and everything was built with 802.11b that could be. We all know the advantages of 802.11a over 802.11b, higher throughput, less congestion etc but client support meant 802.11b stormed the market. Then 802.11g came along in 2003 and there was even less need to move to 802.11a as 802.11g in the 2.4 GHz spectrum was as fast as 802.11a and more accessible.

We waited an awfully long time for 802.11n with many many false dawns, it finally became a standard on September 11th 2009, about tea time if I recall, well that’s when I got the news. Just for the record 802.3af became a standard on the same day but was eclipsed by the hoopla surrounding 802.11n.

802.11n was so different its a whole new set of rules for us wireless engineers to learn, channel bonding, MIMO, frame aggregation, block acknowledgements etc etc and promises up to 600 Mbps.

Well now we have 802.11ac, there is little out in the real world that goes into any great depth about this proposed new standard, however, it is being touted that it will be a standard in December 2012, that’s not far away at all.

All is not lost however as it seems that it will largely an evolution of 802.11n or at least some of the technologies. The basis for the enhanced speeds, over 1 Gbps, will be further channel bonding with talk of 80 MHz and even 160 MHz wide channels. Now it would appear that this would only be feasible in the 5.0 GHz spectrum as there are not enough reusable channels in the 2.4 GHz spectrum. Even with all the available channels in the 5.0 GHz spectrum it is unlikely that there would be enough non overlapping air space to deploy an enterprise cell based implementation as we do today. Slight improvements in modulation techniques will also push up the speed.

A major breakthrough could come in the form of MU-MIMO (multiple user MIMO) where simultaneous streams are given to users on the same channel.

Product may hit markets as early as next year however I get the general feeling that it will have more specific applications than 802.11n due to the channel bonding and would be ideal for streaming HD video or high speed PtP or PtmP implementations.

802.11ac also has a big sister, 802.11ad, similar technologies but working up to 60GHz where I believe there is a lot of spectrum available. This however would be severely limited in its signal propagation as we all know the higher the frequency the poorer the range so 60GHz is going to be working between two devices in relatively close proximity.

One thing is for sure, the wireless market place is technologically innovative and our jobs and skills will only be more valuable as we ride the crest of the wave.

Wireless Standards

I was looking for info on the next generation wireless standard 802.11ac and came across this.

Its a good outline of all the current standards, ammendments and recommended practices and includes download links for some standards that are freely available.

I have thoughtfully copied the links to the download locations to save you the hassle of clicking everything and put in a few additional links that I could find.

IEEE 802.11: The WLAN standard was originally 1 Mbit/s and 2 Mbit/s, 2.4 GHz RF and infrared [IR] standard (1997), all the others listed below are Amendments to this standard, except for Recommended Practices 802.11F and 802.11T.

IEEE 802.11-2007 A new release of the standard that includes amendments a, b, d, e, g, h, i & j. (July 2007)

IEEE 802.11a-1999 54 Mbit/s, 5 GHz standard (1999, shipping products in 2001)

IEEE 802.11b-1999 Enhancements to 802.11 to support 5.5 and 11 Mbit/s (1999)

IEEE 802.11d-2001 International (country-to-country) roaming extensions (2001)

IEEE 802.11e-2005 Enhancements: QoS, including packet bursting (2005)

IEEE 802.11F-2003 Inter-Access Point Protocol (2003) Withdrawn February 2006

IEEE 802.11g-2003 54 Mbit/s, 2.4 GHz standard (backwards compatible with b) (2003)

IEEE 802.11h-2003 Spectrum Managed 802.11a (5 GHz) for European compatibility (2004)

IEEE 802.11i-2004 Enhanced security (2004)

IEEE 802.11j-2004 Extensions for Japan (2004)

IEEE 802.11k-2008 Radio resource measurement enhancements (2008)

IEEE 802.11n-2009 Higher throughput improvements using MIMO (multiple input, multiple output antennas) (September 2009)

IEEE 802.11p: WAVE—Wireless Access for the Vehicular Environment (such as ambulances and passenger cars) (working—June 2010)

IEEE 802.11r-2008 Fast BSS transition (FT) Working "Task Group r" (2008)

IEEE 802.11s: Mesh Networking, Extended Service Set (ESS) (working—September 2010)

IEEE 802.11T: Wireless Performance Prediction (WPP)—test methods and metrics Recommendation cancelled

IEEE 802.11u: Interworking with non-802 networks (for example, cellular) (working—September 2010)

IEEE 802.11v: Wireless network management (working—June 2010)

IEEE 802.11w-2009 Protected Management Frames (September 2009)

IEEE 802.11y-2008 3650–3700 MHz Operation in the U.S. (2008)

IEEE 802.11z: Extensions to Direct Link Setup (DLS) (August 2007 – December 2011)

IEEE 802.11aa: Robust streaming of Audio Video Transport Streams (March 2008 – June 2011)

IEEE 802.11ac: Very High Throughput <6 GHz; potential improvements over 802.11n: better modulation scheme (expected ~10% throughput increase); wider channels (80 or even 160MHz), multi user MIMO; (September 2008 – December 2012)

IEEE 802.11ad: Very High Throughput 60 GHz (December 2008 – December 2012)

IEEE 802.11ae: QoS Management

IEEE 802.11af: TV Whitespace

IEEE 802.11mb: Maintenance of the standard. Will become 802.11-2011. (Expected publication 8/02/11)

For those withh some money to spare at the end of all the books and lab gear you will be buying 80211n


Well after a few days with blogger I have spent far too much time trying to get it how I want it but its looking OK at the moment.

I think there are certainly things that would be easier to accomplish with more control but I am not an HTML guru so I will stick with it for now. I also have a great deal on at the present time.

Eventually I think I will host my blog elsewhere and rid myself of the shackles that are imposed by Google Blogger.

Don't get me wrong I wouldn't have this up and running if it wasn't as easy as it is but there are restrictions that I think I could get around by hosting it myself. I also think that I will outgrow the capabilities of Blogger before the year is out.

CWNA Objectives

Here is a link to the CWNA exam objectives.

I have also put together a spreadsheet that is a copy of the objectives to help guide your study and assess your knowledge.

In order to get the best out of the spreadsheet grade your competency in the rating column honestly as its only you that you will be cheating, for example "1" is I haven't got a clue what that means and a "5" will be I am very comfortable with that subject area.

Feel free to edit the spreadsheet how you see fit to help with your studies.

Wireless Forums

I thought it may be a good idea to point to some of the forums that I find useful in my pursuit of resources that directly relate to wireless. These are forums that may be easily found however I rate the people who post in these forums very highly. I don't think there is a better way to stay upto speed on whats happening in wireless than the collective knowledge of sites like these.

First off is the CWNP website, I rate this site as it is vendor neutral and has a very active forum with some very knowledgeable people there to answer your queries. They also have a certification program that will take you from entry level wireless novice to subject matter expert. I intend to post more on the certifications available within the wireless industry in another post but I rate this highly due to its breadth and depth of coverage.

Secondly there is of course Cisco, although Cisco do all things network related and more their wireless forums are maturing quite nicely with the extension of their wireless certification program. Check out the NetPro forums and the Cisco Learning Network. From within the Learning Network there are also specific stuudy groups for their wireless certification. Again a good resource with very knowledgeable people.

In the interest of fairness many other manufacturers have forums, equally and disappointingly some don't. Below are two additional forums you may wish to check out. I can't comment on them as I have never been on them.



Sunday, 25 April 2010

Saturday, 24 April 2010

CWNA Study Guide Chapter 1 Communications Fundamentals Key Learning Points

These are what I feel are the key learning points from chapter 1 of the CWNA Study Guide, knowing and understanding these will help pass the CWNA exam

Standards Bodies

IEEE - Institute of Electrical and Electronics Engineers
FCC - Federal Communications Commission
ITU-R - International telecommunication Union - Radiocommunication Sector
TELEC - Telecom Engineering Center
ETSI - European Telecommunications Standards Institute
WECA - renamed to Wi-Fi Alliance in 2000
WFA - Wi-Fi Alliance
ISO - International Standards Organisation

Wi Fi Alliance Programs

802.11 a/b/g/n
WPA2 - based on 802.11i
WMM - based on 802.11e
WMM-PS - WMM Power Save
WiFi Protected Setup - easy setup for home wifi networks using PIN, push button, usb etc
CWG-RF (Converged Wireless Group - RF Profile) - defines performance metrics for wi-fi ad cellular radios in converged handsets ensuring both technologies perform well in the presence of each other
Voice Personal - for SOHO environments supprting upto 4 calls

Future Wi Fi Alliance Programs

Voice Enterprise - due in 2010

RF Fundamentals

Carrier wave is a signal that is modified (modulated) to convey data

Each of the following can be modulated to convey information


Keying Methods

Know the difference between current state and state transition.
Keying methods are also know as modulation techniques.b

ASK - Amplitude Shift Keying
Varies amplitude and uses current state
Susceptible to interference

FSK - Frequency Shift Keying
Varies frequency and uses current state
Found in some legacy 802.11 systems

PSK - Phase Shift Keying
Varies the phase and uses state transition
If phase changes per symbol period "1"
If no phase change per symbol period "0"
Advanced versions of PSK can encode multiple bits per symbol period.


Just want to say a warm welcome to my blog.

I satrted this blog as an aid memoire to myself and with the idea that some of the information may help others. It will also act as a repository for information related to wireless, my study notes and things I may just find interesting.

I have recently recertified my CCNA and taken the CCNA Wireless and Cisco AWLANFE. Very soon I will be taking the Cisco AWLANSE and the CCDA.

This blog will focus on wireless but may occasionally leap off to other things related to networking as I will also be studying the CCNP.

Current focus will be on the CWNA. Ok why am I studying CWNA if I already have the CCNA Wireless, well the CWNA covers the fundamentals. Although I have been in wireless for a number of years I know I will learn alot from the CWNA as there have been alot of changes since I last read the CWNA book.

My goals are to aim high. Hopefully this blog will help me achieve them and support others. CCIE Wireless and CWNE are my goals so there will be alot of study and alot of long days and nights.

On the journey are many interim exams and knowledge gaps to fill, hopefully I will understand some but ultimately learn an awful lot.