IFSYSCTL(5)						       Network configuration						       IFSYSCTL(5)

NAME

       ifsysctl[-<interface name>] - per network interface sysctl settings

SYNOPSIS

       /etc/sysconfig/network/ifsysctl
       /etc/sysconfig/network/ifsysctl-<interface name>

DESCRIPTION

       These files are intended to contain sysctl settings, that should be applied when a network interface is created. This are usually interface
       specific settings, like:

	    net.ipv6.conf.eth0.use_tempaddr = 1
       or
	    net.ipv4.conf.eth0.rp_filter = 0

       The settings are applied by the /etc/sysconfig/network/scripts/ifup-sysctl script executed via /etc/udev/rules.d/77-network.rules rule (see
       udev(7)),  after  the  creation	and  after  the rename of the interface name to its persistent name (when applicable), but before the ifup
       <interface name> -o hotplug may be executed to configure the interface.

       The settings are not applied by default when the NetworkManager is active (NETWORKMANAGER=yes), except when the IFSYSCTL_NETWORKMANAGER=yes
       variable is set in the /etc/sysconfig/network/config file.

       Settings from the ifsysctl- file are applied every time an interface has been created.

       Settings from the ifsysctl-interface name file are applied when the interface with the corresponding interface name has been created.

SYNTAX

       The  sysctl(8) utility is required to apply the settings. It supports two separator characters for sysctl keywords: a "." in default format
       and a "/" in the alternate format.  Therefore the syntax is basically same to the /etc/sysctl.conf file.

       Interface names may contain a ".". In the default sysctl format using a "." as separator, that is any "." in the interface name of the key-
       word, has to be replaced with a "/". In the alternate sysctl format with "/" as separator, normal interface names can be used.

       Optionally,  the ifsysctl files may contain also the $INTERFACE and the $SYSCTL_IF variables, that are automatically replaced with the cur-
       rent interface name usable in the alternate format and with the sysctl-quoted interface name for the default format,  before  the  settings
       are passed to the sysctl utility.

       Note also, that settings with variables in the ifsysctl (without the -<interface name> suffix), will be applied for every interface!
       Further, files with variables are not compatible to the /etc/sysctl.conf file.

EXAMPLES

       Settings for "eth0" and "eth0.1" interfaces
	    # using "." as separator:
	    net.ipv6.conf.eth0.use_tempaddr = 1
	    net.ipv6.conf.eth0/1.use_tempaddr = 1

	    # using "/" as separator:
	    net/ipv6/conf/eth0/use_tempaddr = 1
	    net/ipv6/conf/eth0.0/use_tempaddr = 1

       Settings with variables:
	    # using "." as separator:
	    net.ipv6.conf.$SYSCTL_IF.use_tempaddr = 1

	    # using "/" as separator:
	    net/ipv6/conf/$INTERFACE/use_tempaddr = 1

       To test your ifsysctl-eth0 or ifsysctl file, use:
	    /etc/sysconfig/network/scripts/ifup-sysctl eth0 -o debug

BUGS

       Please report bugs at <https://bugzilla.novell.com/>

AUTHOR

       Marius Tomaschewski <mt@suse.de>

SEE ALSO

       ifup(8) ifcfg(5) sysctl(8)

sysconfig							   December 2009						       IFSYSCTL(5)