Cisco IOS ACL logging with Port numbers

Cisco IOS logging with source and destination ports Recently I had to do some troubleshooting on a Cisco 2911 Router in order to find out if traffic is going from a certain IP address to another. So I did the usual created an extended Access List and then applied it to the interface like this:… Continue Reading Cisco IOS ACL logging with Port numbers

Art of Communication

Not much time to write about some technical stuff so decided to write about some random thoughts going through my mind about Communicating with others, they may be your peers, your family members, customers, management, elders, kids, vendors there is an art to communicate with all of them and in business circles and corporate communication… Continue Reading Art of Communication

Common Cisco WLC commands

Graphical interfaces are cool and some people prefer them period. I however believe that everything has its use and personally I love to utilize command line anytime I can when it comes to troubleshooting, configuring or looking at information. Yes there are times when I do like to use a GUI but especially when it… Continue Reading Common Cisco WLC commands

CWAP – Group Key Handshake

Group Key Handshake is a two way handshake that happens when an access point needs to deliver a new GTK to all client stations. GTK is used to encrypt the broadcast and multicast traffic. An important thing to remember here is that this is a separate process as opposed to PTK generation, if it was… Continue Reading CWAP – Group Key Handshake

CWAP – 802.11 Frames

So with 802.11 there are different types of frames they they all have sub-types. Knowing these frames and where to find them is helpful when capturing data. It is not fun trying to get them in your head when studying for the test, however in my opinion it is easy when you are actually looking… Continue Reading CWAP – 802.11 Frames


802.11 is Layer 2 and Layer 1. After frames come to Layer 1 from PPDU pre 802.11-2016 standard shows there are two interfaces PLCP and PMD as show below. NOTE: Per 802.11-2016 there is no longer PMD and PLCP, please read this article R.I.P. PMD by Robert Haviland explaining it really well. Since my post… Continue Reading CWAP 403 – PHY (PLCP)

CWAP – Machine State/EAP/4-Way Handshake

This is something that keeps coming up while studying for different certifications and I always have to review everything, flip through the pages since there are technically 3 sections here, I decided to write up a quick overview of all 3 including the flow as shown in the diagram below. When a Wireless Client connects… Continue Reading CWAP – Machine State/EAP/4-Way Handshake

Brocade ICX 6450 PoE Configuration

Recently I configured a Brocade ICX6450 PoE switch on the network and all was working well until my customer hooked up a phone to one of the ports I configured. I was told that the phone won’t power on. Now on a Cisco PoE Switch, I’m used to just simply plugging in phones and getting power. With the Brocade… Continue Reading Brocade ICX 6450 PoE Configuration

Cisco 1142 not joining Cisco 2504 WLC

%PKI-3-CERTIFICATE_INVALID_NOT_YET_VALID Recently I was setting up my lab environment with a Cisco 1142 Access Point and a Cisco 2504 Wireless LAN Controller and I ran into a minor issue. Cisco 1142 Access Point was not joining the WLC. I was getting the following error message when I consoled into the access point. *Jan 1 04:35:10.126:… Continue Reading Cisco 1142 not joining Cisco 2504 WLC

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