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Showing posts from October, 2014

Survey For Your WiFi Clients

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When designing WiFi networks, a crucial part of the design process is the wireless survey. This may be a traditional ‘AP on a stick’ survey or may be an off-site, ‘desktop’, predictive survey. In amongst the variety of variables that need to be considered, including coverage and capacity, there is one crucial item that is easy to forget: how does the designed wireless network look from the point of view WiFi clients that will actually use the network? Background Best practice for wireless surveying usually dictates that prior to completing a survey for a new WiFi deployment design, a pre-survey questionnaire will be supplied to your customer. This document will ask about the environment that the network is to be deployed into. It will include information such as physical building characteristics, cabling and switch infrastructure, health and safety considerations, access arrangements etc.   In addition, the pre-survey questionnaire will also request information from the c...

ISE's Evil Default

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Whilst working with Cisco ISE recently, I became aware of a setting within the product that could be a major ‘gotcha’ if you aren’t aware of it. We’ll take a very quick look at it in this article. Background Tucked away in the depths of the Cisco ISE menu structure is a rather innocent-looking configuration setting under the ‘Anomalous Client Detection’ section of the System Settings. The option I’m referring to can be found in the following location in ISE 1.2: Administration > System> Settings > Protocols > RADIUS The screenshot below shows the settings page I am discussing: The settings on this page have been provided to protect ISE in the face of an onslaught of misbehaving or mis-configured clients that may flood it with authentication traffic (and hence RADIUS traffic). In larger environments, this could become an issue and affect ISE’s performance. Suppress Anomalous Clients The tick-box ‘Suppress Anomalous Clients’ provides a very ...

Converting Images For Survey and Management Tools

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Being able to convert electronic floor plans into formats supported by a wireless survey or management tool is a regular part of being a WiFi professional. A customer may often provide floor plans in a format that isn’t accepted by the particular tool that you are using, leaving you with a file-conversion headache. In this article we take a look at a solution (for Windows users) to convert two common file types into a useable format. Background When using a professional wireless survey tool, one of the first steps in preparing your survey project is to import an electronic copy of the building floor plans. The plans are used to show areas surveyed and the RF measurements (“heapmaps”) that have been taken. Similarly, once a WiFi network has been installed, there is often a requirement to import floor plans into a network management system (NMS) to show the areas covered by the new deployment. This may be a cloud-based console or perhaps a dedicated on-site management server...