50 lines
2.8 KiB
Markdown
50 lines
2.8 KiB
Markdown
Contiki network I/O on Microsoft Windows (including the Cygwin environment) is
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implemented based on the quite popular WinPcap library that is available at
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[http://winpcap.org](http://winpcap.org).
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Developing Contiki network applications most likely involves working with a
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network protocol analyzer. Wireshark (formerly known as Ethereal) is a very
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popular one that on Windows uses - and actually comes with - the WinPcap
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libary. Wireshark is available at [http://wireshark.org](http://wireshark.org).
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So with Wireshark installed Contiki network I/O doesn't need any additional
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components.
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On Windows every Contiki application has one obligatory comand line argument
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that identifies the Windows network interface to be used by Contiki. While on
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Unix those network interfaces are called i.e. '/dev/tap0' they have on Windows
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names like
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\Device\NPF_{F76B480A-1D31-4B3D-8002-C0EF49185737}
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In order to avoid the necessity to enter such names on the command line instead
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the IPv4 address used by Windows is entered to identify the network interface
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to be used by Contiki. Please note that this IPv4 address is _NOT_ the IPv4
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address to be used by Contiki !
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Contiki network I/O on Windows uses the same MAC address used by Windows. This
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approach often described as IP-Aliasing was primarily chosen because it avoids
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putting the network interface into promiscuous mode. The major benefit of this
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is the compatibility with WLAN interfaces - which mostly come with Windows
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device drivers incapable of promiscuous mode.
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The WinPcap library works fine with the 'Microsoft Loopback Adapter' so it's
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easy to have a Contiki network application running on Windows communicate with
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the local Windows instance for testing purposes - and monitor the communication
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with Wireshark.
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Windows Vista however tries to identify networks by the MAC address of the
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default router. If that fails the network is defined as an 'Unidentified
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Network' and thus classified as 'Public Network' resulting in very strict
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firewall settings. As there's no default router for a loopback interface the
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interface is always considered as a public network - which is kind of the
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opposite of the actual situation ;-)
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Instead of fiddling with the firewall settings for 'Public Networks' (or even
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turning the firewall completely off) there's a clean solution which defines the
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loopback interface as not a true network interface that connects to a network.
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This results in generally deactivating both the network identification process
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and the firewall for the loopback interface. The details are available in the
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Microsoft TechNet Forums thread 'Vista Network Identification for Loopback
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Adpater' that is currently available at
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[link](http://social.technet.microsoft.com/forums/en-US/itprovistanetworking/thread/66b42761-1b8e-4302-9134-0bb685139f4e)
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