10.8.5 Network configuration and PCMCIA

There are several possible approaches to configuring PCMCIA network interfaces (for 2.4 and 2.6 kernels).

• For 32 bit PCI (CardBus) PCMCIA network cards:

  • ifupdown controlled by hotplug

    • In Woody and Sarge you must locally enable hotplug's control of ifupdown by adding a mapping stanza to /etc/network/interfaces as described in Triggering network configuration – hotplug, Section 10.8.2.

• For 16 bit ISA PCMCIA network cards:

  • ifupdown controlled by hotplug with pcmcia-cs confined to loading modules

    • Recommended

    • In Woody and Sarge you must locally disable pcmcia-cs's default behavior of controlling ifupdown by adding the line exit 0 to the beginning of /etc/pcmcia/network. Also, you must locally enable hotplug's control of ifupdown by adding a mapping stanza to /etc/network/interfaces as described in Triggering network configuration – hotplug, Section 10.8.2.

  • ifupdown controlled by pcmcia-cs via the default /etc/pcmcia/network

    • Deprecated but still the default for Woody and Sarge

  • low level tools controlled by pcmcia-cs via special code in /etc/pcmcia/network

    • Deprecated

    • In Woody and Sarge the special code is enabled by editing /etc/pcmcia/network.opts

The recommended approach for 16 bit cards takes advantage of the fact that the Linux 2.4 hotplug subsystem now supports PCMCIA. [64]

PCMCIA network cards are hot pluggable. Accordingly, any services that require networking through a PCMCIA card should be so configured that they get started on card insertion and get stopped on card removal. This is usually accomplished by arranging for the service to start on ifup and stop on ifdown. Some people, however, choose to confine themselves to cold plugging their PCMCIA network card: they insert the card before booting the system and they start services that require networking through the card in the boot sequence. If you are such a person then in order to ensure that the card is fully configured before the services are started you should do the following:

• Set CARDMGR_OPTS="-f" in /etc/default/pcmcia in order to force cardmgr to run in the foreground.

• Rename /etc/rc?.d/S20pcmcia to something like /etc/rc?.d/S12pcmcia.

This hack only works for 16 bit PCMCIA cards.

Note that pcmcia-cs is still needed if you use 16 bit PCMCIA cards. The cardmgr daemon that the package contains is responsible for managing the sockets and loading driver modules. We just don't want it to call network configuration programs via /etc/pcmcia/network.

In order for cardmgr to work properly you may need to edit /etc/pcmcia/config.opts in order to configure resources assigned to 16 bit PCMCIA cards. See PCMCIA, Section 7.2.1 and the Linux PCMCIA HOWTO for more information.