INTEL WIRELESS
Wired Stuff
WiFi Tablet Corner
My80211 White Papers (Coming Soon!)

Cisco Wireless Compatibility Matrix (Nov. 2011)

Podcasts / Videos

My80211 Videos

Cisco: 802 11 frames with Cisco VIP George Stefanick

Fluke Networks: Minimize Wi Fi Network Downtime

Aruba: Packets never lie: An in-depth overview of 802.11 frames

ATM15 Ten Talk “Wifi drivers and devices”

Houston Methodist Innovates with Wireless Technology

Bruce Frederick Antennas (1/2)

 

Bruce Frederick dB,dBi,dBd (2/2)

Cisco AP Group Nugget

Social Links
Revolution WiFi Capacity Planner

Anchor / Office Extends Ports

 

Peek Inside Cisco's Gear

See inside Cisco's latest wireless gear!

2.4 GHz Channel Overlap

EXAMPLE 1  

EXAMPLE 2

EXAMPLE 3  

CWSP RELEASE DATE 2/08/2010
  • CWSP Certified Wireless Security Professional Official Study Guide: Exam PW0-204
    CWSP Certified Wireless Security Professional Official Study Guide: Exam PW0-204
    by David D. Coleman, David A. Westcott, Bryan E. Harkins, Shawn M. Jackman

    Shawn Jackman (Jack) CWNE#54 is a personal friend and has been a mentor to me for many years.  I've had the pleasure and opportunity to work with Jack for 4 years. Jack is a great teacher who takes complex 802.11 standards and breaks them down so almost anyone can understand the concept at hand. I'm excited for you brother. Great job and job well done! Put another notch in the belt!

IEEE 802.11a/g/n Reference Sheet

 

LWAPP QoS Packet Tagging

 

 

Interference Types

BLUETOOTH
 

Microwave Oven
 

Cordless Phone

JAMMER!
 

  

Saturday
Dec122009

IPhone App: WiFi Scanner ~ WiFiFoFum 

I tried a few of the IPhone WiFi scanners, nothing to write home to mom about. Until I tried WiFiFoFum scanner. It reminds me of Netstumber from back in the day, but with the GPS option. This scanner not only scans for WiFi networks, but it also records the location via GPS for later review. It records the data in a KML file that you can email yourself and drop into google maps or review right from your IPhone.

There are 4 radio buttons:

Networks - This button displays the basics ~ SSID, mac address, RSSI, data rates and if the network is secure.

Radar - Pretty useless. It gives you a visual of how close you are. If you are in the crosshairs you are on the money.

Logging - The logging function is pretty cool. When you enable logging it will record your position when your IPhone heard the access point. Once you stop the logging it records your data in a file with the date and time. You click on that file and a google map pops up showing you the access points it found. You can also send yourself the file, its in a KML file.

Settings - The last button is the settings button. All the basic here, scan rate, RSSI filter, etc.

 

Saturday
Dec122009

Core Knowledge Questions Now on All CCIE Labs

The long awaited announcement from Cisco about the Core Knowledge questions. As part of the Cisco CCIE Wireless Certification the candidate is required to answer 3 /4 questions in 30 minutes. If you fail the core knowledge section, you automatically fail your lab attempt regardless if you pass the lab section.

Effective January 4, 2010, the CCIE® Service Provider, Storage, and Wireless Lab Exams will add a new type of question format in a section called Core Knowledge. In this new section, candidates will be asked a series of four open-ended questions which require a short written response be entered into the computer--typically several words. The questions will be randomly drawn from a pool of questions on topics eligible for testing. Candidates can review the topics by visiting the CCIE track information on Cisco.com or Cisco Learning Network. No new topics are being added as a result of this change. Candidates will have up to 30 minutes to complete the Core Knowledge section and may not return to it once they have moved on. A passing score on the Core Knowledge section is required to achieve certification. Core Knowledge questions were implemented on Routing and Switching labs in February 2009, Security labs in June 2009, and Voice labs in July 2009, and allow Cisco to maintain strong exam security and ensure only qualified candidates are awarded CCIE certification. Candidates with exam dates January 4, 2010 or later should expect to see the new question format on their lab exam.
To find out more information regarding updates to the CCIE Lab and scoring format, please click here to go to the CCIE Q&A section.

Wednesday
Dec092009

WLC CLI Command To Change AP Duplex <auto/half/full> and Speed <auto/10/100/1000> <all/Cisco AP Name>

Here is another nugget to put in the bag and only can be done in the CLI of a WLC. Suppose you want to modify the duplex and speed of the ethernet side of an AP or all the APs for that matter. By default both the duplex and speed are set to auto.

This is how -- drop down into the CLI of the WLC. This command lives under the <ap> catagory. 
(Controller) config ap ethernet duplex <auto/half/full> speed <auto/10/100/1000> <all/Cisco AP Name>

 

Sunday
Dec062009

Bugs: CSCtd46886 - 6.0.188.0 shows incorrect boot loader version

So I wasn’t losing my mind after all. In between projects I attempted to update the bootloader on my personal controller and the new WiSMs I just deployed. Both running 6.0.188.0. I tried over 10 times, each time I got a successful TFTP transfer and did a reload. But the new bootload wouldn’t take. I searched the release notes and docs. In fact I learned more about the WLC bootloader chasing this issue down.

So I gave in and called TAC.  Here is what I was told:

There are two know bugs that fit the issue you are having 1) CSCsy99596    Need to bundle bootload into ER image and 2) CSCtd46886    WLC with version 6.0.188.0 shows incorrect boot loader version.  Both are new bugs and have not been resolved as yet.

I understand CSCtd46886 is dated 11/25/09. 

Just wanted to share incase you come across this issue…

Saturday
Dec052009

802.11: Null Data Frames

I was speaking to a friend last evening on the topic of client troubleshooting. The discussion came up about roaming and roaming aggressiveness. We talked about the different aspects of client behavior and the discussion turned into an 802.11 frame discussion. More specifically the NULL frame.

The Null Data Frame is a very interesting frame. In fact, most folks overlook these frames, perhaps because they don’t know their importance. Just a few months ago I was troubleshooting a client issue and the NULL frame confirmed by idea and backed my findings as it pertained to a wireless issue I was troubleshooting

Lets look at the NULL frame and it's importance. 

The Null Data Frame is a control frame. It is only transmitted by a STA (wireless client). Access points do not transmit these frames. It carry’s no data payload. In fact, the only purpose of this frame (by standard) is to carry the power management bit in the frame controlled field. The power management bit will be either "0" zero or "1" one. 

When the STA sends a power management bit of "0" to the access point in which it is associated to, it is the STAs way of informing the access point that the STA is in an active power state (awake) and transmission of frames from access point to STA should be normal.  

When the STA sends a power management bit of "1" to the access point in which it is associated to. This is informing the access point that the STA is going offline and any frames that come into the access point for this STA should be buffered at the access point till the STA returns and sends a NULL frame of "0", active state. 

A text example of the exchange: 

STA ---NULL FRAME "0"----->  AP "Client says to the AP: Hey AP I’m online send me data"

 

STA ---NULL FRAME "1"----->  AP "Client says to the AP: Hey AP buffer any transmissions coming in for me. Ill be back in a bit (no pun intended)"

 

So why would a client go offline and what is the importance !?!?! Its very important. Lets talk through a few examples. 

There are two main reasons why a STA will go offline, or send a power man bit of "1" to an access point.

Power Save Mode: PSM allows a STA to go into "sleep or doze" mode. PSM essentially turns off the NIC radio for short burst to conserve battery power for a device. You will notice significant power conservation and longer battery life when PSM is enabled. VoIP phones, PDAs and other small battery form factor devices benefits from PSM. A word of *caution*, be aware that some applications can suffer from aggressive power save mode options. 

Active/Passive Scanning: The other reason why a STA will inform an access point to buffer its frames by sending a power man bit of "1" is when it’s ready to roam. Suppose a client has hit its roaming threshold and is seeking out another access point to associate to. In order to seek out other access points in the area it has to go off channel. By doing so, the STA tells the AP, buffer the frames man, ill be back for them in a bit!

Example:

The STA is on AP TEST, AP test is on channel 1

The client will send a NULL FRAME to the access point with the man bit of 1. The STA goes offline and floods channels 2,3,4,5,6,7,8,9,10,11 (depending on configuration of the client of course) with probe request looking for other APs.

Lets look at a packet capture:

Note frame 75 - This is my STA sending the AP a Data Null Frame. If you open the packet and drill down into the frame control you will see the power management bit is set 1.

 

Note frame 78 - This is my STA sending the AP a Data Null Frame. Note that the power bit is set to 0. Indicating to the STA is back on channel and any data that was buffered and future date should be sent to the client until its next doze state. 

Note frame 82 - STA is going back to bed!

 

What is also interesting to note is the TIME stamp. Look at the time delta between frames 75 - 78. This is the period of time the STA was off line, generally speaking.

You might ask when does the client come back online to the AP. Well that is dependent on how the STA is configured. For example, Intel has what I call the "slide bar" for PSM. The more aggressive the mode the longer the STA will be in sleep or doze mode. 

Now that you know what a NULL frame is and its purpose. If you are troubleshooting a STA issue pay attention to what the STA is telling the access point! If a client is sending NULL frames there is a reason why!

Wednesday
Dec022009

12/2/09 - End-of-Life Announcement for the Cisco 526 Wireless Express Mobility Controller

Cisco announced the end of life and end of sale for the Cisco 526 Wireless Express Mobility Controller. You probably didn't even know Cisco had a controller 526 and 500 series APs, did you? This product line was an attempt to market to small price point customers who wanted a controller based  product with enterprise features. The 526 / 500 line had no compatibility between the 2100 / 4400 / 5500 / WiSM product line. So you couldn't take a 500 series AP and have it join a 4400 series controller. I mentioned when Cisco released this, it was doomed from the start. I didn't see this product taking hold in the market.

Title: End-of-Sale and End-of-Life Announcement for the Cisco 526 Wireless Express Mobility Controller  [Cisco 500 Series Wireless Express Mobility Controllers]
Url: http://www.cisco.com/en/US/prod/collateral/wireless/ps7306/ps7320/ps7339/end_of_life_c51-568040.html
Description: Cisco announces the end-of-sale and end-of life dates for the Cisco 526 Wireless Express Mobility Controller. The last day to order the affected product(s) is June 1, 2010. Customers with active service contracts will continue to receive support from the Cisco Technical Assistance Center (TAC) as shown in Table 1 of the EoL bulletin. Table 1 describes the end-of-life milestones, definitions, and dates for the affected product(s). Table 2 lists the product part numbers affected by this announcement. For customers with active and paid service and support contracts, support will be available until the termination date of the contract, even if this date exceeds the Last Date of Support shown in Table 1.
Date: 2009-12-01 07:11:34.0

Title: End-of-Sale and End-of-Life Announcement for the Cisco 500 Series Wireless Express Access Points  [Cisco 500 Series Wireless Express Mobility Controllers]
Url: http://www.cisco.com/en/US/partner/prod/collateral/wireless/ps7306/ps7320/end_of_life_c51-568039.html
Description: Cisco announces the end-of-sale and end-of life dates for the Cisco 500 Series Wireless Express Access Points. The last day to order the affected product(s) is June 1, 2010. Customers with active service contracts will continue to receive support from the Cisco Technical Assistance Center (TAC) as shown in Table 1 of the EoL bulletin. Table 1 describes the end-of-life milestones, definitions, and dates for the affected product(s). Table 2 lists the product part numbers affected by this announcement. For customers with active and paid service and support contracts, support will be available until the termination date of the contract, even if this date exceeds the Last Date of Support shown in Table 1.
Date: 2009-12-01 07:11:32.0

Sunday
Nov292009

Cisco – 802.11n shootout with Aruba,Motorola and HP

I just stumbled on a 4 part youtube video I believe posted by Cisco on a side by side “shootout” of 802.11n performance testing between Cisco, Aruba, Motorola and HP, 802.11n offerings. Their testing was conducted in a greenfield environment and deployed various tools to monitor performance. Cisco came out smelling like a dozen roses (no, let me take that back, 2 dozen roses) as they conducted the test themselves. But needless to say, I think there is value in watching the videos. They have a solid test approach with added real world examples, or should I say test samples.

HP took two black eyes and a bloody nose in these videos. Gezzz…

Btw, I would hate to be the poor soul sitting underneath that 1252 access point hanging from the t-bar.  

802.11n Performance - Testing Setup (Part 1 of 4)

http://www.youtube.com/watch?v=AYfITpf6VEQ&feature=related

802.11n Performance - Throughput vs. Distance (Part 2 of 4)

http://www.youtube.com/watch?v=A5rowgtTSj8&feature=related

802.11n Performance - Coverage (Part 3 of 4)

  http://www.youtube.com/watch?v=3UGm6KtUErI&feature=related

802.11n Performance - Capacity Test (Part 4 of 4)
 http://www.youtube.com/watch?v=ak5iHbASH9s 

 
Sunday
Nov292009

Web Power Switch II

The name is a bit misleading, it not a switch really, well kind of, but not the switch you are thinking of. I was looking for an inexpensive power management solution to control the various components in the lab. Electric is pretty expensive here in Houston and having a rack full of equipment doing nothing when not is use is just a waste of money. I looked at other remote power solutions but price was a hugh factor in my decision making process. I discovered remote power management isn’t cheap! I saw solutions in the hundreds and even in the thousand dollar range.  I also didn’t want to compromise reliability and usability either over a cheap solution.

After much surfing, reading and research I decided on Digital Loggers (www.webpowerswitch.com) Web Power Switch II. I have to say, it’s not the prettiest thing and it’s not rack mountable 1u form.  They do sell a rack mount kit but I didn’t purchase it, it just didn’t look right. Outside of those two draw backs I am really pleased with the performance for the price. For starters it was only $135.00 with shipping.  My order shipped the next day after placing the order. The plug is a 15 amp connector and comes with 8 ports that allow for remote management and 2 additional power ports that are "unswitched" or unmanaged.

The web interface is pretty basic. You can configure and name each outlet for easier identification when managing what devices you want to turn on or off. Comes with a basic syslog which reports the status of the power switch and any changes. Get this, it has an auto ping feature that will automatically power reset an outlet if it loses connectivity with a device. Outside of it being an ugly duckling I'm more then satisfied

Monday
Nov232009

WLC CLI command to change AP <Username> <Password> to ALL APs

The more you experiment and live in the CLI of a WLC you will find little nuggets that you can’t do in the GUI. This little find is just one of them. The AP USERNAME command allows you to change the username and password for ALL of the access points that are connected to the controller.Why is this important you might wonder? The obvious of course. Even if your AP is lightweight someone can still telnet, ssh or console into the AP with Cisco / Cisco.  

This command allows you to change ALL or individual APs usernames and passwords. This comes in handy after a new deployment.   

(Cisco Controller) config>ap <username> GEORGE <password> MY80211 <ALL or name of individual ap>

Sunday
Nov222009

Cisco Medical-Grade Network (MGN) 2.0— Wireless Architectures

Cisco released their MGN 2.0 - Wireless Architectures document this week. Nothing earth shattering here but it is a good refresh for healthcare organizations to take a pulse of what offerings there are in the healthcare wireless vertical.

This document does a brief overview of wireless design, location, security, network management and Jcaho.
I love how Cisco trashes DAS and puts them under the bus. DAS + 802.11 is a VERY BAD MIX. Just my 2 pennys. DAS is great for other wireless transport modes, just keep WiFi off of it... I remember when DAS hit the market. Cisco wasn't sure how to handle it. I'm glad they are stepping away from supporting DAS deployments. If you don't read the entire document. Read the DAS section.

"Cisco does not certify, endorse or provide support for Wi-Fi deployments over any distributed antenna
system. The DAS vendor or integrator is solely responsible for the support of the DAS products and for
any RF-related issues. This includes location accuracy, RF coverage, roaming issues related to RF,
multipath issues, and scalability. While Cisco Technical Assistance Center (TAC) and Cisco field teams
do not provide support for RF issues that arise in a Cisco WLAN used over a DAS, they will, however,
provide support for non-RF related issues if they arise"
Cisco mentions in this document that WEP is not an acceptable security posture for healthcare. Nothing new, I know. But there are tons of hospitals still using WEP and this read will likely end up on the C levels desk and perhaps new direction may come down from the top to not use WEP.
"Wireless Networks which use Open Authentication, Wired Equivalent Privacy (WEP) or Cisco's WEP
Extension using CKIP) are no longer considered Medical Grade due to their weak security."
Friday
Nov202009

Cisco Released SIO iPhone Application today

I admit I'm an IPhone app junky. I surf iTunes daily for my next fix. I gave the new Cisco SIO IPhone app a spin today. SIO stands for "Security Information On-the-Go" If you are a security professional or someone who keeps up with latest alerts this is an app you would want to consider. As for me i like the security blog and Cisco field notices of the app.

Cisco SIO To Go iPhone Features

Powered by the Cisco Security IntelliShield Alert Manager Service, the Cisco SIO To Go iPhone application informs, protects and enables users to respond in real time to alerts and threats to the network. The application delivers early warning intelligence, threat vulnerability and proven Cisco mitigation solutions to users' iPhones as they occur. It also provides unique IP and URL address e-mail and Web reputation look-up powered by the Cisco IronPort® SenderBase Security Network and the Cisco SIO.

Alerts delivered include:

Cisco Product Security Incident Response Team (PSIRT) Alerts

Cisco Intrusion Prevention Systems (IPS) Signatures

Cisco Applied Mitigation Bulletins

Cisco Threat Outbreak Alerts

And many others

Links to the following Cisco security news and information:

Cisco Security Blog

Cisco Cyber Risk Report

Cisco Press Releases

Cisco Security Twitter Feed

Cisco Security Podcasts

 
Friday
Nov202009

WiSM Auto-LAG Feature 

When installing WiSMs in the past I would do it the old fashion way. You know, create my 4 port channels (2 for management) (2 for the controllers), configure the 8 gig interfaces (these come up once the WiSM is installed), and assign these to the port channels.

Software release 12.2(18)SXF5(Sup 720) has a new WiSM feature call "auto-lag". I am always cautions with anything with the word "auto" when it comes to networking. However I was pleasantly surprised with the new feature.  So what is auto-lag --  auto-lag allows you to configure a controller with 3 simple commands rather then doing the multiple steps.

Lets walk through the steps of auto-lag. In this example we will configure a WiSM in MOD 3 controller 1. We will be have native vlan 100 and allow vlans 200,201,202 and 203. These are my wired interfaces which tie to SSIDs.

 

#> wism module 3 controller 1 native an 100 <--- This creates a native vlan. This is used for your controller management (untagged)

#>wism module 3 controller 1 allowed-vlan native 100, 200, 201,202,203 <--- This allows which vlans are allowed

#>wism module 3 controller 1 qos-trust dscp <--- Good ol' QoS

 

 This is the output of the show run with auto lag. Note you will not see the gig interfaces and the port channel in the show run output, as you would normally expect to. But don’t worry they are there.

 

#>show run

wism module 3 controller 1 allowed-vlan 100,200-203

wism module 3 controller 1 native-vlan 100

wism module 3 controller 1 qos-trust dscp

 

If you want to see the etherchannel you can

#>show etherchannel      

          Channel-group listing:

        -----------------------

 Group: 287

----------

Group state = L2

Ports: 4   Maxports = 8

Port-channels: 1 Max Port-channels = 1

Protocol:    -

Minimum Links: 0

Tuesday
Nov172009

reset the WLC to factory default settings using the CLI

This week I am configuring (2) 6504's with 4 WiSMs for a brand new installation. We are deploying Cisco's new 1142 802.11n access points in a location grade deisgn. As part of the deployment and configuration I needed to restore one of the WiSMs back to factory default. I wanted to share with you the procedure and CLI commands. 

1. First, you need to reset the controller. Enter reset system at the command prompt. 

2. At the prompt that asks whether you need to save changes to the configuration, enter Y or N, doesn’t matter what you select. The controller will then reboot. 

3. When you are prompted for a username, enter recover-config to restore the factory default configuration.

 Press enter and the controller will reset back to factory default.

Saturday
Nov142009

Cisco WLC "linktest" - How well does the AP hear your client? 

A wireless connection is a two way street. All to often Admins will ONLY look at what the Client reports from the AP (how well it hears the AP - client radio receive sensitivity). But have you considered how well the AP hears your client ??

We call this "access point-to-client". For a better understanding, think back when you were a kid and your dad yelled at you for not taking out the trash the night before trash day. Your dad is very loud -- to get his point across and everyone in the house (or neighborhood) can hear him! Perhaps, you answer back to your dad with a low, soft," I’m sorry, I forgot"... Your dad heard your response as a whisper .

In this example your dad is the access point @ 100mW  power (loud) and you are the wireless client @ 5mW power (low). You as the wireless client heard your dad loud and clear, but your dad didn't hear you so well. 

 

 

When you check your wireless supplicant and it registers -75dB, this is how loud you hear the AP (or your Dad in my example) - Again this is "access point-to-client".

But you want to see how well the AP (or your Dad in my example) hears you,  "client to-access point". . With a Cisco WLC you can perform a LINKTEST. This can be done in the GUI, WCS or CLI. Here is the command in the CLI. 

 

(Cisco Controller) >linktest 00:02:10:11:02:68 <-- Wireless NIC MAC Address

The beauty of Cisco CCX is that when enabled on both the client and controller it will report back both access point-to-client and client to-access point readings. 

When CCX v4 is enabled on both the controller and the client being tested, information similar to the following appears: 

CCX Link Test to 00:02:10:11:02:68.

     Link Test Packets Sent...................................... 20

     Link Test Packets Received................................. 10

     Link Test Packets Lost (Total/AP to Client/Client to AP).... 10/5/5

     Link Test Packets round trip time (min/max/average)......... 5ms/20ms/15ms

     RSSI at AP (min/max/average)................................ -60dBm/-50dBm/-55dBm

     RSSI at Client (min/max/average)............................ -50dBm/-40dBm/-45dBm

     SNR at AP (min/max/average)................................. 40dB/30dB/35dB

     SNR at Client (min/max/average)............................. 40dB/30dB/35dB

     Transmit Retries at AP (Total/Maximum)...................... 5/3

     Transmit Retries at Client (Total/Maximum).................. 4/2

     Transmit rate:  1M   2M   5.5M   6M   9M  11M 12M 18M   24M   36M  48M  54M  108M

     Packet Count:   0     0     0    0    0    0   0   0     0     2    0   18     0

     Transmit rate:  1M   2M   5.5M   6M   9M  11M 12M 18M   24M   36M  48M  54M  108M

     Packet Count:   0     0     0    0    0    0   0   0     0     2    0    8     0

When CCX v4 is not enabled on either the controller or the client being tested, fewer details appear:

Ping Link Test to 00:02:10:11:02:68.

        Link Test Packets Sent.......................... 20

        Link Test Packets Received...................... 20

        Local Signal Strength........................... -58dBm

        Local Signal to Noise Ratio..................... 29dB

 

You can also config the default "linktest" settings:


(Cisco Controller) config>linktest ?
frame-size     Configures linktest frame-size for each packet.
number-of-frames Configures number of frames to send for linktest.

Again, another reason WHY a proper wireless site survey is needed and why you need to always consider your lowest common denominator (client) for wireless reliability. If your dad (AP) is always yelling and you (client) always whisper back you are bound to have COMMUNICATION problems. Vocera is one of these such applications.

 

Thursday
Nov122009

Restore the backup image on your WLC

You just loaded that new code on your WLC and something blew up! Quickly you scramble to start looking through the manual or start downloading and reapplying the previous level of code.

Did you know the controller saves the previous version of code on the controller and all you have to do is change the boot image to active? When you upgrade the WLC with a new image , the WLC automatically writes the new image as the primary image and the previously existing primary image is written over the backup image.

Note: The previously existing backup image will be lost ! 

Below are snips of a backup in progress 

(Cisco Controller) >show boot

Primary Boot Image............................... 4.2.176.0 (active)

Backup Boot Image................................ 4.2.130.0

 

(Cisco Controller) config>boot ?

primary        Sets the primary image as active.

backup         Sets the backup image as active.


(Cisco Controller) config>boot backup


(Cisco Controller) >reset system

The system has unsaved changes.

Would you like to save them now? (y/N)

 

(Cisco Controller) >show boot

Primary Boot Image............................... 4.2.176.0

Backup Boot Image................................ 4.2.130.0 (active)

Monday
Nov092009

Enable / Disable LEDs on Cisco LWAPP APs

Working as a consultant for many years you see it and hear it all! I had a situation one time where we deployed a new Cisco WLC solution. I was asked by the management of the hospital if we could turn off the LEDs on the access points in the "crazy ward" as the access points caused a lot of extra attention.

This is real easy to accomplish. In fact you can disable all the AP LEDs or specific ones. If you choose to select specific access points you will need to know the name of the ap. First drop down into the Controller CLI.

'config ap led-state enable/disable <Cisco AP name | all>'


CLI disable specific access point LED named lab1131

(Cisco Controller) config>ap led-state disable lab1131

 

CLI disable all access points LEDs

(Cisco Controller) config>ap led-state disable all

 

 
Sunday
Nov082009

Wireless NIC problem or just poor quality? 

This evening I did benchmark testing on a wireless client which I want to share. I was working on a Samsun NQ unit with an integrated Atheros AR5007EG wireless NIC. I was told by the user the client would lose connectivity and had a slow network connection when connected. So I go through the normal check list, do I have signal for data- check, is the noise floor low -  check, do I have expected PHY data rates - check.  But this test was conducted right under the access point.

As I get distance between the client and the access point (also know as free space path loss) I see the wireless client signal strength nose dive hard.

So I check all the normal things, antenna connection, driver update, NIC config. All these check out OK. So I do side by side benchmark testing with a known good wireless NIC and notice an almost a 20 dBm difference. As you know all wireless NICs will hear (receive sensitivity) differently. But with advancements today, you will see most NICs are all generally in the same ballpark. I say that lightly and tip toeing.

Below is a snap shot of both clients, Samsung has the Atheros AR5007EG and my laptop Intel2915AG. Both clients are side by side at the same distance from the access point. I did further testing by adding another laptop for consistency. I also added a Cisco Linksys WUSB600N to the Samsung.

I don’t have another Samsung to test and it’s not my unit so I wont be taking it apart to investigate further. But the moral of the story, never ever discount the client. Each client will hear differently, and soemtimes a client may have issues or be a poor design.

 

 

 

Saturday
Nov072009

Dropbox.com File Sharing at its best (IPhone app included!)

Recently I was introduced to Dropbox file sharing. I am that shiny object kind of guy and dropped what I was doing to investigate Dropbox (Thanks Brandon, lol). First, I found the ease of uploading and file management so much better than other file share apps. I was also impressed with how easy it is to share public files and how to manage those files or folders. The kicker and deal closer for me, yup the IPhone app just drove this out of the park. You can d/l the Dropbox app and you have full access to ALL your files and better yet, from the Dropbox IPhone app you can share and invite others to share your folders. So if you’re a busy engineer or just a file freak  in general this app is for you. I see myself migrating to this more then my FTP.

Dropbox give you 2 gig free. You can purchase 50 gig @ $10 a month and 100 gig @ $20 a month. Well worth the investment!

www.dropbox.com

Thursday
Oct292009

What you NEED to know about TX Power and 802.11a (5GHz) on a Cisco LWAPP AP

Power, power power.... One of the MOST important design factors is selecting the proper radio TX power when designing any wireless network. You must consider your lowest common denominator and adjust your power equally between your client and AP for optimal design.

But did you know when you select different UNII channels in the 5 GHz band you are also changing the TX power of your AP on a Cisco WLC? When selecting power on a cisco ap in the WLC you are presented with the power levels 1,2,3,4,5 etc. Most folks are aware on the 2.4 GHz side power levels.

1 = 20 dBm / 100mW
2 = 17 dBm / 50mW
3 = 14 dBm / 25 mW
4 = 11 dBm / 12.5 mW

But did you know depending on the UNII band you select the power levels are different on the 802.11a 5GHz radio.

UNII 1                                                 UNII 2 / 3

1 = 11 dBm / 12.5 mW                          1 = 17 dBm / 50mW
2 = 8 dBm / 6.25 mW                            2 = 14 dBm / 25 mW
3 = 5 dBm / 3 mW                                3 = 11 dBm / 12.5 mW
4 = 2 dBm / 1.5 mW                              4 = 8 dBm / 6.25 dBm

 

(Cisco Controller) >debug ap enable <Name of AP>
(Cisco Controller) >debug ap command "show controller do 1" <Name of AP>

Note:

"show controller do 0" is interface Dot11Radio0
"show comtroller do 1" interface Dot11Radio1

UNII-1 POWER LEVEL - Controller Power Level 1

(Cisco Controller) >
Thu Oct 29 10:37:02 2009: afa0:
Thu Oct 29 10:37:02 2009: afa0: !

Thu Oct 29 10:37:02 2009: afa0: interface Dot11Radio0

Thu Oct 29 10:37:02 2009: afa0: Radio AIR-RM1252A, Base Address 001d.70dd.afa0, BBlock version 0.00, Software versi
on 2.00.22
Thu Oct 29 10:37:02 2009: afa0: Serial number: XXXXXXXXXXXXXXX

Thu Oct 29 10:37:02 2009: afa0: Number of supported simultaneous BSSID on Dot11Radio0: 16

Thu Oct 29 10:37:02 2009: afa0: Carrier Set: Americas (OFDM) (US) (-A)
Thu Oct 29 10:37:02 2009: afa0: Uniform Spreading Required: Yes
Thu Oct 29 10:37:02 2009: afa0: Configured Frequency: 5180 MHz  Channel 36  40Mhz, extended above (Power 1)
Thu Oct 29 10:37:02 2009: afa0: Allowed Frequencies: 5180(36) 5200(40) 5220(44) 5240(48) *5260(52) *5280(56) *5300(
60) *5320(64) *5500(100) *5520(104) *5540(108) *5560(112) *5580(116) *5660(132) *5680(136) *5700(140) 5745(149) 576
5(153) 5785(157) 5805(161) 5825(165)

Thu Oct 29 10:37:02 2009: afa0: * = May only be selected by Dynamic Frequency Selection (DFS)Thu Oct 29 10:37:02 2009: afa0: Listen Frequencies: 5180(36) 5200(40) 5220(44) 5240(48) 5260(52) 5280(56) 5300(60)5320(64) 5500(100) 5520(104) 5540(108) 5560(112) 5580(116) 5660(132) 5680(136) 5700(140) 5745(149) 5765(153) 5785(1
57) 5805(161) 5825(165)

Thu Oct 29 10:37:02 2009: afa0: Beacon Flags: 0; Beacons are enabled; Probes are enabled
Thu Oct 29 10:37:02 2009: afa0: Configured Power: 14 dBm

Thu Oct 29 10:37:02 2009: afa0: Active power levels by rate

Thu Oct 29 10:37:02 2009: afa0:      6.0 to 54.0  , 14  dBm
Thu Oct 29 10:37:02 2009: afa0:      m0. to m15.-4, 11  dBm, changed due to regulatory maximum
Thu Oct 29 10:37:02 2009: afa0:   OffChnl Power: 14, Rate 6.0

Thu Oct 29 10:37:02 2009: afa0: Allowed Power Levels:  -1 2 5 8 11 14
Thu Oct 29 10:37:02 2009: afa0: Allowed Client Power Levels: 2 5 8 11 14
Thu Oct 29 10:37:02 2009: afa0: Receive Antennas : right left middle

Thu Oct 29 10:37:02 2009: afa0: Transmit Antennas : right left, ofdm single
Thu Oct 29 10:37:02 2009: afa0: Antenna: external, Gain: Allowed 11, Reported 11, In Use 11

UNII-2/3 POWER LEVEL - Controller Power Level 1

(Cisco Controller) >
Thu Oct 29 10:34:21 2009: afa0:

Thu Oct 29 10:34:21 2009: afa0: !

Thu Oct 29 10:34:21 2009: afa0: interface Dot11Radio0
Thu Oct 29 10:34:21 2009: afa0: Radio AIR-RM1252A, Base Address 001d.70dd.afa0, BBlock version 0.00, Software versin 2.00.22
Thu Oct 29 10:34:21 2009: afa0: Serial number: XXXXXXXXXXXXXXX
Thu Oct 29 10:34:21 2009: afa0: Number of supported simultaneous BSSID on Dot11Radio0: 16
Thu Oct 29 10:34:21 2009: afa0: Carrier Set: Americas (OFDM) (US) (-A)

Thu Oct 29 10:34:21 2009: afa0: Uniform Spreading Required: YesThu Oct 29 10:34:21 2009: afa0: Configured Frequency: 5745 MHz  Channel 149  40Mhz, extended above (Power 1)
Thu Oct 29 10:34:21 2009: afa0: Allowed Frequencies: 5180(36) 5200(40) 5220(44) 5240(48) *5260(52) *5280(56) *5300(
60) *5320(64) *5500(100) *5520(104) *5540(108) *5560(112) *5580(116) *5660(132) *5680(136) *5700(140) 5745(149) 576
5(153) 5785(157) 5805(161) 5825(165)

Thu Oct 29 10:34:21 2009: afa0: * = May only be selected by Dynamic Frequency Selection (DFS)Thu Oct 29 10:34:21 2009: afa0: Listen Frequencies: 5180(36) 5200(40) 5220(44) 5240(48) 5260(52) 5280(56) 5300(60)5320(64) 5500(100) 5520(104) 5540(108) 5560(112) 5580(116) 5660(132) 5680(136) 5700(140) 5745(149) 5765(153) 5785(157) 5805(161) 5825(165) 

Thu Oct 29 10:34:21 2009: afa0: Beacon Flags: 0; Beacons are enabled; Probes are enabled
Thu Oct 29 10:34:21 2009: afa0: Configured Power: 20 dBm
Thu Oct 29 10:34:21 2009: afa0: Active power levels by rate
Thu Oct 29 10:34:21 2009: afa0:      6.0 to m15.-4,
17  dBm, changed due to regulatory maximum
Thu Oct 29 10:34:21 2009: afa0:   OffChnl Power: 14, Rate 6.0
Thu Oct 29 10:34:21 2009: afa0: Allowed Power Levels:  -1 2 5 8 11 14 17 20
Thu Oct 29 10:34:21 2009: afa0: Allowed Client Power Levels: 2 5 8 11 14 17 20
Thu Oct 29 10:34:21 2009: afa0: Receive Antennas : right left middle
Thu Oct 29 10:34:21 2009: afa0: Transmit Antennas : right left, ofdm single
Thu Oct 29 10:34:21 2009: afa0: Antenna: external, Gain: Allowed 11, Reported 11, In Use 11

 

 
Wednesday
Oct282009

CCIEs Worldwide (10/26/09)

Geo - "Cisco updated CCIE counts this week. Man I am taken back by the CCIE Wireless count. To date only 15, yes that’s right 15 people have passed the CCIE lab worldwide! The US lab is booked till March 2010. Do the math, packed labs for the next 5 months and only 15 passes!?!?

The CCIE wireless lab has taken a lot of folks by surprise. Not only I, but others questioned the value of a CCIE Wireless certification. I think Cisco is living up and exceeding expectations in the Wireless lab difficulty. You will earn your badge by passing this lab!

I had the privilege to take part in a small study group this week. The participants weren’t your normal every day engineers, but rather folks that have reached the CCIE peek more than once. In fact, one gentlemen has 5x CCIEs and he is determine to be the second human on earth to have 6x valid IE's, behind Roman. He himself commented, "This lab is up there in difficulty with the voice lab"."