The an driver provides support for Aironet Communications 4500 and 4800 wireless network adapters and
variants, including the following:
• Aironet Communications 4500 and 4800 series
• Cisco Aironet 340 and 350 series
• Xircom Wireless Ethernet Adapter
Support for these devices include the ISA, PCI and PCMCIA varieties. The Aironet 4500 series adapters
operate at 1 and 2Mbps while the Aironet 4800 series and Cisco adapters can operate at 1, 2, 5.5 and
11Mbps. The ISA, PCI and PCMCIA devices are all based on the same core PCMCIA modules and all have the
same programming interface, however unlike the Lucent WaveLAN/IEEE cards, the ISA and PCI cards appear to
the host as normal ISA and PCI devices and do not require any PCCARD support.
The PCMCIA Aironet cards require PC Card support, including the kernel pccard(4) driver. ISA cards can
either be configured to use ISA Plug and Play or to use a particular I/O address and IRQ by properly
setting the DIP switches on the board. (The default switch setting is for Plug and Play.) The an driver
has Plug and Play support and will work in either configuration, however when using a hard-wired I/O
address and IRQ, the driver configuration and the NIC's switch settings must agree. PCI cards require no
switch settings of any kind and will be automatically probed and attached.
All host/device interaction with the Aironet cards is via programmed I/O. The Aironet devices support
802.11 and 802.3 frames, power management, BSS (infrastructure) and IBSS (ad-hoc) operation modes. The
an driver encapsulates all IP and ARP traffic as 802.11 frames, however it can receive either 802.11 or
802.3 frames. Transmit speed is selectable between 1Mbps, 2Mbps, 5.5Mbps, 11Mbps or "auto" (the NIC
automatically chooses the best speed).
By default, the an driver configures the Aironet card for infrastructure operation.
For more information on configuring this device, see ifconfig(8).