Tag Archives: iOS

DHCP Fingerprinting with ArubaOS

If you’ve read any of my previous blog posts, you have probably noticed that I make an effort to confine my posts to vendor-neutral topics. However, every now and then I come across vendor-specific technology implementations that are so cool that I just have to say something about them. In this case, it is DHCP fingerprinting by Aruba Networks.

Without getting into too much technical detail, this technology watches the DHCP requests of wireless clients and identifies the operating system based on the way each device asks for an address. This feature is really cool because it means you can allow a user to connect to the same ESSID (read: wireless network), using the same username/password, with a variety of different devices, and get different levels of access depending on the specific device type. For example, if the user connects to the WLAN with a company issued laptop then they get access to the internal network. However, if they connect using an iPad they get Internet access only. Didn’t I say this was cool?

Enough typing, I recorded a little demonstration of DHCP fingerprinting for your viewing enjoyment:

As BYOD becomes more prevalent, I think we are going to start seeing technologies like this popping up all over the place. This is a good thing since it gives administrators the ability to allow BYODs onto the network without having to give up on security and control.

Dan C.

How do you deal with BYODs in your environment? If you have thoughts or comments regarding the proper way of dealing with BYODs please share them in the comments section. Also, as usual, please share this post with others if you found it useful or interesting.

Are iDevices a guest WLAN’s best friends?

A quick look at the June and July usage statistics from the Milton Public Library guest wireless network reveals some interesting statistics regarding device usage versus data usage. Based on the past two months, iDevices (iPhones, iPods, and iPads) tend to have a much smaller data usage footprint than standard laptops.

First let’s look at the number of unique devices that connected to the guest WLAN in the month of July. Not surprisingly, iDevices accounted for 45% of all devices using the guest network. This can be attributed to the portability of these devices compared to standard laptops.

When we look at the total data usage by device type we see that iDevices only accounted for 19% of the total while laptops accounted for a disproportionate 80% of all data usage in July. This indicates that, while more popular and abundant, iDevices are not putting as much load on the guest WLAN infrastructure and data pipe as standard laptops.

Why the discrepancy?

There are several reasons why iDevices currently use far less data than their laptop counterparts:

  1. Mobile versions of videos and other web-content are generally smaller than the full-sized, HD versions being consumed by laptops.
  2. Application updates on laptops are generally much larger than on iDevices.
  3. OS updates can occur wirelessly on laptops and not on iDevices (this will be changing very shortly in iOS 5).
  4. People tend to use laptops and desktops as their primary file-sharing platforms rather than iDevices due to functionality and storage limitations. That being said, peer-to-peer networking did not make the top 10 list of apps used on the MPL guest WLAN thanks to some well-defined traffic shaping rules.

What’s Next?

Apple’s iCloud service might take iDevices from ‘low data consumption’ status to ‘high data consumption’ status in the next few months to come. There is potential for a huge increase in data usage for these devices as more and more people take advantage of iCloud’s music syncing service. The month of June saw iTunes related traffic account for 3.3% of all guest WLAN usage. This grew to 8.2% in the month of July. It will be interesting to see just how much higher this percentage will climb in the near future. If the climb does occur, iDevices may be shifted from the ‘best friend’ category to the ‘worst enemy’ category rather quickly.

Dan C.

I would like to thank the Milton Public Library for allowing me to reference their WLAN statistics. Without their assistance, this post would not have been possible. If you have any questions or thoughts on this post please leave a comment.