wi fi security

Having to maintain the security of a wireless networkredirected by a particularly sophisticated captive
is something that's probably new to most users, andportal.
it can often be frustrating due to all the newOnce you sign in and pay up, the captive portal stops
information you have to assimilate.interfering with your traffic, and reverts to the usual
How Wi-Fi hotspots force you to log in.'pass through' mode. The next time you try to
It's an everyday scenario: you go to a hotel or Wi-Ficonnect, it checks your identity (usually by looking at
hotspot and find a wireless or wired connection, butyour machine's relevant MAC address) and silently let
instead of getting your homepage when you bring upyou through if you are still in the time-window of
your browser, you get a custom page from theservice. Otherwise, it's back to square one.
service provider asking you to pay for the service.So, to summarize, the captive portal provider needs:
You've hit a captive portal, and it's how the servicea redirection mechanism for Web traffic, a
provider makes sure that they get paid for whattraffic-blocking mechanism of some sort (firewall,
they are offering.802.1x, etc) to constrain you, a sign-in facility, a
The technology is relatively simple because you are,payments gateway of some sort, and some form of
by definition, using their network. They configureidentity repository for keeping track of who is a
their systems to accept your initial network traffic (inpaid-up known customer and who is not.
this case, your request for Web content from yourNone of these components are particularly obscure
homepage's server) but instead of passing thator difficult to find, but if you are looking to build a
request along, they redirect you to their sign-in page.captive portal you probably shouldn't try to reinvent
This redirection can be done in a number of ways,the wheel. You can find complete packaged
but the basic functionality is built into the httphardware-and-software solutions from the usual
standard (the status codes in the 300-range describesuspects (Cisco, Juniper, etc), as well as smaller-scale
the various options). Any non-web traffic, such assoftware solutions from multiple vendors. If you
SMTP for email, or FTP, is typically blocked using awant to use free and open-source software, you'll
firewall of some type, but may be caught andeasily be able to find many solutions on-line.