War Chalking

War chalking is the act of drawing symbols on sidewalks and walls to advertise the existence of an AP (Figure 4.17). Not exactly graffiti, war chalking was inspired by the markings used by hoboes during the Great Depression to communicate with one another. Their symbols indicated messages such as “Good place for a handout,” “Look out for dog,” and “Free telephone.” In modern times, war chalking is used to describe nodes as open, closed, or WEP, as well as the SSID, bandwidth, and contact info.

Figure 4.17. War chalking.

If you see one of these symbols outside your home or building, you've been war chalked. For more information about ...

Get How Secure Is Your Wireless Network? Safeguarding Your Wi-Fi LAN now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.