DEVICE=<name>

[ BOOTPRIO=number ]
  ifcfg-* interfaces are configured in BOOTPRIO order starting
  from lowest value first. You need to set BOOTPRIO in _all_ your
  ifcfg* files because if you won't do that only these interfaces
  with BOOTPRIO variable will be configured. Use the same schema
  when setting variable for example BOOTPRIO=number
  or BOOTPRIO="number" because sorting is done by sort command.

[ BOOTPROTO={none|bootp|dhcp|pump} ]
  You can specify which dhcp client to use with the DHCP_CLIENT, if
  the DHCP_CLIENT is not specified we trying to launch in order :
  /sbin/dhcpcd
  /sbin/dhclient
  /sbin/dhcpxd
  /sbin/pump
  if you have a preferred client define the DHCP_CLIENT variable.
  You can also pass some options to dhcp client via DHCP_OPTIONS.

[ BOOTPROTO6={none|dhcp6|v4compat}
  dhcp6 isn't supported, yet.
  v4compat uses available IPv4 addresses (ie. from DHCPv4)
  and then convert them to IPv6 (IPv4-compatible) to use with
  automatic tunnels


IPADDR="(IPv4 or IPv6 address)/prefix"
IP_AOPTS="broadcast xxx etc" (by default broadcast is autocalculated)
IP_ROPTS=""
IP_LABEL=""

IPADDR1=
IP_AOPTS1= options for ip addr add
IP_ROPTS1= options for ip route add (currently used only for IP4_PRIM_IF)
IP_LABEL1= IPv6 address label as per RFC 3484 (ip addrlabel ...)

IP4_PRIM_IF="1"		# number of primary IPv4 interface (IPADDRx)
IP4_SRC_IF="1"		# number of IPv4 address for ip's ,,src'' parameter
IP6_PRIM_IF=""		#

[ ONBOOT={no|yes} ]
[ HOTPLUG={no|yes} ] - bring up from hotplug (udev for example) (default to no)
[ MULTICAST={|no|yes} ]	- for eth automatically set to yes
[ ARP={no|yes} ]	- for eth automatically set to yes
[ IPV6_DISABLE_AUTOCONF={yes|no} ] - disable IPv6 autoconfiguration

[ IPX=yes|no ]
if	IPX=yes ; then

	IPXNETNUM_{802_2,802_2TR,802_3,EtherII,SNAP}
	IPXPRIMARY_{802_2,802_2TR,802_3,EtherII,SNAP}=yes|no
	IPXACTIVE_{802_2,802_2TR,802_3,EtherII,SNAP}=yes|no
fi

[ MTU= ]
[ METRIC= ]
[ PROXYARP={yes|no} ]

QDISC=[sfq|teql0|red|prio|...] (queueing discipline)
QDISC_CLASS=[htb|cbq|none]     (use cbq|htb as class based discipline;
                                if none specified and bandwidth_out present
                                then tbf is used)
BANDWIDTH_IN=[upstream limit in kilobites, supported on 2.4 only]
BANDWIDTH_OUT=[downstream limit in kilobites]

VLAN_REORDER_HDR=[0|1]	When this is set, the VLAN device will move the
			ethernet header around to make it look exactly like a
			real ethernet device.  This may help programs such
			as DHCPd which read the raw ethernet packet and
			make assumptions about the location of bytes.
			If you don't need it, don't turn it on, because there
			will be at least a small performance degradation.
			Default is ON.

[ VLAN_GVRP=yes|no ]    Enable GVRP.

[ DEFAULTHANDLING=yes|no ] (used in configuration for ATM interfaces,
			    obsolete variable)
[ HANDLING=0|1|2|3 ] (0 is default; used ie. in ATM configuration, for
		      details see ifup script)

[ CHECK_LINK_WAIT_TIMEOUT=<wait max x sec for interface link up> ]

if 	DEVICE=eth*; then

	[ MEDIA={auto|10baseT|10base2|AUI} ]
	[ MACADDR=<hw address> ]

	if macvlan
		MACVLAN_DEV=<exitsting base interface eg. eth0>
		MACVLAN_MACADDR=<desired hw address of new interface>
		MACVLAN_MODE=<desired mode of new interface (private, vepa, bridge, passthru, source)>
	fi
	

	if 	DEVICE=wireless interface (man iwconfig(8))
		WLAN_UPEARLY=<yes>|<no> Up device before setting any WLAN parameters
					(needed for some drivers)
		WLAN_ESSID=<ESSID or Network Name (Domain ID)>|any|off
		WLAN_NWID=<Network ID (Domain ID)>|off
		WLAN_FREQ=<frequency> (2.422G)
		WLAN_CHANNEL=<channel number> (3)
		WLAN_SENS=<the sensitivity threshold>
		WLAN_MODE=ad-hoc|managed|master|repeater|secondary|auto
		WLAN_AP=<Access Point address>|any|auto|off
		WLAN_NICKNAME=<station nickname)
		WLAN_BITRATE=<bitrate like 11M>|auto|fixed
		WLAN_RTS_THRESHOLD=<rts/cts threshold>|auto|fixed|off
		WLAN_FRAGMENTATION_THRESHOLD=<frag threshold>|auto|fixed|off
		WLAN_KEY=XXXX-XXXX-XXXX-XXXX|XXXXXXXX|s:<ascii string>
		if WLAN_KEY; then
			WLAN_KEY_1=... <optional>
			WLAN_KEY_2=... <optional>
			WLAN_KEY_3=... <optional>
			WLAN_KEY_4=... <optional>
			WLAN_KEY_CURRENT=index <optional>
		fi
		WLAN_ENCRYPTION=on|off|open|restricted
		WLAN_POWER=period <value>|timeout <value>|on|off|all|unicast|multicast
		WLAN_TXPOWER=<power in dBm>|<power in mW>mW|auto|on|off
		WLAN_RETRY=limit <value>|lifetime <value>
		WLAN_COMMIT=yes|no (some cards require manual commit of changes)
		if WLAN_WPA=yes; then
			WLAN_WPA_WAIT_TIMEOUT=<wait max x sec for wpa_suplicant>
			WLAN_WPA_DRIVER=<driver: see -D option of wpa_supplicant; default is wext>
			WLAN_WPA_CONFIG=<path to wpa_supplicant config file>
			WLAN_WPA_OPTIONS=[additional wpa_supplicant options]
		fi
	fi

elif	DEVICE=ppp* || DEVICE=sl* ; then

	PERSIST=yes|no
	MODEMPORT=<device, say /dev/modem>
	LINESPEED=<speed, say 115200>
	DEFABORT=yes|no
        DIRECT_CONNECT=yes|no (direct connection without chat/wvdial used for example
			       on SDI or leased lines)

	if	DEVICE=ppp* ; then

		AUTH=yes|no
		PEERDNS=yes|no
		DEFROUTE=yes|no
		ESCAPECHARS=yes|no
		SYNC=yes|no (yes implies "sync" option)
		HOLDOFF=30
	  	HARDFLOWCTL=yes|no (yes implies "modem crtscts" options)
    	 	PPPOPTIONS=<arbitrary option string>
		PAPNAME=<"name $PAPNAME" on pppd command line>
		REMIP=<remote ip4 address, normally unspecified>
		REMIP6=<remote ip6 address, normally unspecified>
    		MRU=
    		DISCONNECTTIMEOUT=<number of seconds, default currently 5>
    		RETRYTIMEOUT=<number of seconds, default currently 60>
    		INITSCRIPT=<modem command>
    		DATAFORCHAT=<list of variables>
    		<anything>=<anything> (for chat script)
		IPV6_PPP=yes|no (use IPv6 for ppp ?)
		if IPV6_PPP = yes ; then
			IPV6_CP_USEV4=yes|no (use local IPv4 mapped addresses
					      as IPv6 addresses)
			IPV6_CP_PERSISTENT=yes|no (use EUI-48 addresses
						   as IPv6 addresses; not
						   supported on Linux, yet)
			or by default use address specified by IP6_PRIM_IF
			and REMIP6
		fi
		PPPOA=yes|no (generic PPP over ATM)
		if PPPOA = yes ; then
			PPPOA_VPI=<VPI number>
			PPPOA_VCI=<VCI number>
		fi
		PPPOE_DEV=<ethX> (PPP over Ethernet device)
		if PPPOE_DEV exists ; then
			PPPOE_KERNEL=yes|no (use or not kernel space PPPoE support)
			PPPOE_OPT=<options> (used only with userspace pppoe program)
		fi
		PPPOA_EAGLE=yes|no (eagle-usb support)
		if PPPOA_EAGLE = yes ; then
			PPPOA_OPT=<options> (used only with userspace pppoa program)
		fi
		PPPOA_SPEEDTOUCH=yes|no (speedtouch support)
		if PPPOA_SPEEDTOUCH = yes ; then
			PPPOA_KERNEL=yes|no (use or not kernel space PPPoA support)
			PPPOA_VPI=<VPI number>
			PPPOA_VCI=<VCI number>
			PPPOA_OPT=<options> (used only with userspace pppoa program)
		fi
		UNIT=yes|no (pass unit option to pppd (depends on DEVICE name)
		             defaults to yes)
		WVDIALSECT= (section in wvdial config maybe)
	fi

	if	DEVICE=sl* ; then	(SLIP)
		PROTOCOL=slip|cslip|adaptive
		REMIP=<remote ip4 address>
		REMIP6=<remote ip6 address, normally unspecified>
	fi

elif	DEVICE=br* ; then	/* Bridge */

	BRIDGE_DEVS=<list of devices betwen which do bridging>
		    Note: separation configuration for devices in this list
		          should be avoided !
	AGEING=<ethernet (MAC) address ageing time in seconds>
	GCINT=<garbage collection interval time for the bridge in seconds>

	SPANNING_TREE=yes|no (enable SPT - Spanning Tree Protocol)
	if	SPANNING_TREE=yes ; then
			BRIDGEPRIO=<bridge's priority; 0-65535; less == better>
			FD=<bridge forward delay time in seconds>
			HELLO=<bridge hello time in seconds>
			MAXAGE=<maximum message age in seconds>
			PATHCOST_PORT=<port number>
			PATHCOST=<cost of the port specified in PATHCOST_PORT>
				Note: both PATHCOST_PORT and PATHCOST must be
				      specified to set cost of port
			PORTPRIO_PORT=<port>
			PORTPRIO=<port priority used by port selection algorithms;
			          a number between 0 and 255>
				Note: see note above
	fi
elif    DEVICE=irda* ; then     /* IrDA */

        IRDAPORT=<device, say /dev/ttyS1>
        DONGLE=<driver, see README.irattach from irda-utils package>
        DISCOVERY=yes|no (starts discovery of remote IrDA devices)
fi

# You can also run commands before/after a device has been brought up or down.
# Just create functions run_up/run_pre_up/run_down/run_pre_down.
run_pre_up()
{
	echo "This will be executed before device is brought up!"
}

run_up()
{
	echo "This will be executed after device is brought up!"
}

run_pre_down()
{
	echo "This will be executed before device is brought down!"
}

run_down()
{
	echo "This will be executed after device is brought down!"
}