XFN (XHTML Friends Network)

A big part of Web 2.0 (over the last decade) has been a move toward the semantic internet, whereas each page is representative of data and it’s relationship… we are, in essence, “training” the internet itself.

XFN markup allows you to identify your relationships to other individuals on the links of your website or blog.

<head profile="http://gmpg.org/xfn/11">

HTML5: (removes the ‘profile’ attribute on <head> as such the updated convention is:
<link rel="profile" href="http://gmpg.org/xfn/11" />

Use in content:
<a href="http://www.skotfred.com/" rel="me">My other site</a>




DNS Prefetching

DNS is much like a phone book for the internet. For each domain name (or subdomain like ‘www’), there is an IP address that resembles a phone number. Getting the matching number for each domain can take some time and make your site appear slow, particularly on mobile connections. Fortunately, you can pre-request this information and speed up your site in most cases.

To enable a domains DNS lookup to be performed in advance of the request, you can add a single line to the <head> section of your page.

<link rel="dns-prefetch" href="//giantgeek.com" />

If you want to explicitly turn on (or off) this behavior, you can add one of the following, or their HTTP Header equivalents:

<meta http-equiv="x-dns-prefetch-control" content="on" />
<meta http-equiv="x-dns-prefetch-control" content="off" />

This is supported in all modern browsers:

  • Firefox 3.5+
  • Safari 5.0+
  • MSIE 9.0+

If should be noted that a similar method can be used to prefetch as page, but I will save that for a different article:
<link rel="prefetch" href="http://www.skotfred.com/" />


Disable Cisco NAC Agent logging

I recently had to use a Windows computer with Cisco NAC installed, and found that there was a lot of disk activity for logging.

These files would grow to approximately 5MB before rotation.

C:\Documents and Settings\All Users\Application Data\Cisco\Cisco NAC Agent\logs\NACAgentLogCurrent.log
C:\Documents and Settings\All Users\Application Data\Cisco\Cisco NAC Agent\logs\NACAgentLogOld.log

To reduce this overhead (when no problems exist), the config file is exposed in XML.

  1. Open C:\Program Files\Cisco\Cisco NAC Agent\NACAgentCFG.xml
  2. Add/modify the LogFileSize attribute to 0 (zero) as shown below:

    <?xml version="1.0" ?>
    <LogFileSize>0</LogFileSize><!-- default 5 -->
  3. Reboot
  4. Remove the old .log files

NOTE: if you ever have networking issues and require support, you will need to restore the default value to ‘5’.