• Skip to content
  • Skip to footer

Packet6

San Francisco Bay Area Wi-Fi Professional Services

  • About Us
  • Blog
  • Services
  • Contact Us

Archives for January 2015

An Overview of inSSIDer

January 27, 2015 by Rowell Dionicio Leave a Comment

inSSIDer Wireless

If you are in need of planning or troubleshooting wifi but you’re on a budget, then inSSIDer by Metageek may be a good start for you. inSSIDer is a tool used to show you what your wireless environment looks like.

inSSIDer comes in two version, inSSIDer and inSSIDer Office.

inSSIDer

  • $19.99
  • Uses built-in wifi
  • For Windows and Mac

inSSIDer for Office

  • $199.99
  • Includes Wi-Spy Mini
  • Assists in troubleshooting interference

Radios and ESSIDs

When you open inSSIDer, and depending on whether you organized the main pane via Radio or ESSID, you will be presented with a list. When organized by Radio you get a number of columns:

All the columns presented by inSSIDer

  • Radio’s MAC address
  • Broadcasted SSID
  • What channel the SSID is on
  • Signal strength (in dBm)
  • Protocol
  • Security
  • Data rates

Select Radio or ESID

Selecting Radio is great if there is usually one access point. If you see two channels listed under the Channel column, e.x. 36+40, it means that wireless network is channel bonding to utilize two 20 MHz channels to form a single 40 MHz channel for increased bandwidth.

Select ESSID and the list of wireless networks will be organized by the SSID name. This is useful if there are multiple access points broadcasting the same SSID. You get the same columns but in addition there is a BSSID count which will tell you how many radios are seen for a particular SSID.

On the first column, under Radio or ESSID, you may see a chain link icon. That shows what SSID your laptop is associated with. [Read more…] about An Overview of inSSIDer

Book Review: CCNP SWITCH 300-115 Official Cert Guide

January 22, 2015 by Rowell Dionicio 1 Comment

Book Review: CCNP SWITCH 300-115There are only a handful of books to select from when studying for the CCNP SWITCH 300-115 exam. It’s tough to make the right decision on a resource for an exam that costs $250 to sit in. My go-to book resource is Cisco Press. In short, I passed the CCNP SWITCH (300-115) exam on January 20th, 2015 with the assistance of CCNP SWITCH 300-115 Official Cert Guide.

When I started studying for this exam on October 31st, 2014, there wasn’t a book available covering the new objectives. I printed the exam objectives and started reading configuration guides. As soon as the books were available, I put an order in with Cisco Press and I was off.

The author, David Hucaby, did a great job with his explanations. The book itself isn’t as big as ROUTE. What I like about this book is it is easy to follow along with Cisco’s objectives. After passing the exam, I can say that it covers it very well. David helped me to understand topics where I was weak. It helped reinforce the fundamentals of Spanning Tree and redundancy such as GLBP.

Within the book are good diagrams and configuration examples. The little details are in there as well such as timers, intervals, etc. You’ll need to remember those for the exam.

In preparation for the exam, each chapter is preluded with a chapter quiz. I used those pre-chapter quizzes after I have read through the entire book. The questions are very good compared to the exam. I dig deeper into other topics where I score lower than 80%. Each chapter has anywhere from 10-15 questions so it’s not something to rely on. [Read more…] about Book Review: CCNP SWITCH 300-115 Official Cert Guide

Windows Server NLB VIP Multicast Mode Through Cisco Switch

January 19, 2015 by Rowell Dionicio 5 Comments

If you are unable to connect to a Windows Server Network Load Balancing (NLB) Virtual IP address configured for Multicast Mode it is because of the way your Cisco switch interacts with Microsoft NLB.

Symptoms

  • Cannot connect to Windows Server NLB Virtual IP address
  • Cannot ping Windows Server NLB Virtual IP address
  • Microsoft NLB Multicast Mode not working

I won’t go into the details of how NLB works but in short, client requests are distributed across different servers. To configure NLB, you can use three modes:

  • Unicast
  • Multicast
  • IGMP

Using Multicast Mode

When using Multicast mode, the cluster members will respond to ARPs using their virtual IP address and a multicast MAC address. Without the proper configuration on the switch you will not be able to connect to the Virtual IP address.

This will not work because within the ARP request packet is a unicast IP address and a multicast MAC address. Troubleshooting it can be frustrating but a Cisco switch will ignore this. Below is the configuration to be done on the switch.

Cisco Switch Configuration

To resolve the problem, create a static ARP entry for the Virtual IP Address to the NLB MAC address. Then create a static MAC address entry to the VLAN and interfaces used by the cluster.

In my case, my virtual IP address is 192.168.10.10 with MAC address of 03bf.0a65.05fa. That IP address is on VLAN 10 and the servers’ interfaces are part of a port-channel, both Port-Channel1 and Port-Channel2.

The following configuration is as follows:

arp 192.168.10.10 03bf.0a65.05fa
mac address-table static 03bf.0a65.05fa vlan 10 interface Port-Channel1 Port-Channel2

Some configuration items to note.. not all Cisco switches will support a static entry of a MAC address to multiple interfaces. In my case I am using a Cisco Catalyst 4500-X in VSS mode. The servers had two network interfaces configured into an EtherChannel.

Studying For the CCNA? Which Books To Read.

January 12, 2015 by Rowell Dionicio Leave a Comment

Books to read for the CCNA certificationAre you planning on studying for the CCNA this year? As we begin the new year, 2015, many will have a goal of studying and acquiring their Cisco CCNA certification. A challenging yet tough goal.

There are many resources available for the future network engineer but there are two books I always recommend to anyone wanting to tackle the CCNA. Both are from Cisco Press and authored by Wendell Odom who does a fantastic job in getting you all the information you need to pass the CCNA.

Depending on how you are going to take the exam you have two options, composite or separate exams.

If you’re studying for the CCNA Routing and Switching composite, 200-120 exam then all you need is CCNA Routing and Switching 200-120 Official Certification Guide.

If you’re going to split the exams in two, which is what I did, then you need the following books:

  • Cisco CCENT/CCNA ICND1 100-101
  • Cisco CCNA Routing and Switching ICND2 200-101

All three books are updated for the latest redesigned CCNA exam.

Why Cisco Press books? They follow the exam objectives. It’s easy to go through while following the blueprint. The CCNA books come with pre-chapter quizzes to test your knowledge of each topic. I recommend taking the pre-chapter quizzes after reading through the material to find out where your weak areas are.

At the end of each chapter there are exercises to reinforce what you just read. Additionally, you are given memory tables of which you should memorize for the exam.

The extra material is aimed at helping you master the topics needed to pass the CCNA exam. The books are very helpful and should be the core part of your study plan.

Do you have any questions? Leave me a comment below.

Wireless Design Resources

January 6, 2015 by Rowell Dionicio 1 Comment

I’m far from calling myself an expert in wireless but I know how to avoid the most common mistakes I see being made in different environments. Because wireless signal is invisible, some may think wireless is easy to deploy. Just pop up a few access points here and there and we’re good to go, right? I wish it were that easy but there’s more to it.

What I love about the wireless industry are the different individuals who are making waves (no pun intended) by giving back. These are engineers who live and breathe wireless and only want to see it improve.

Wireless Capacity Planner

Take Andrew von Nagy, author of Revolution Wifi, as an example. He published a Wireless Capacity Planner which I recommend to anyone who is deploying wireless. I commend his work and generosity to the industry. This tool is essential for explaining the Why in wireless. Included in the planner is an Excel sheet in which you can specify what kind of APs will be deployed and what kind of clients will be using wireless and in the end it will calculate approximately how many radios you should use.

Wireless Capacity Planning

 

It’s obviously a better planning utility than just guessing at which AP to use, how many, etc. Not only do you get the Excel sheet but Andrew also includes a PDF going into wireless capacity planning.

Designing For Capacity

Andrew doesn’t stop there. He has produced exceptional material. One example is his presentation on Designing for Capacity. One of his slides mentions the typical design process which focuses mostly on signal strength and coverage.

Download his presentation and soak in the education.

Education

Revolution Wifi has been a big influence in my career, regarding wireless. I have learned so much from his perspective. One thing I did come to ends with is that the CWNA is highly beneficial to anyone in the wireless industry.

I am currently in my early stages of studying for the CWNA but I have read through the book front to back. It is a lot to take in but very interesting to me. The book is a great place to start if you are just getting started in wireless.

Footer

LET’S TALK

Are you ready to improve your wireless network?

WE'RE LISTENING

© Copyright 2018 Packet6 · All Rights Reserved ·