This module matches on the bridge port input and output devices enslaved to a bridge device. This module is a part of the infrastructure that enables a transparent bridging IP firewall and is only useful for kernel versions above version 2.5.44. .TP .BR --physdev-in " [!] \fIname\fP" Name of a bridge port via which a packet is received (only for packets entering the .BR INPUT , .B FORWARD and .B PREROUTING chains). If the interface name ends in a "+", then any interface which begins with this name will match. If the packet didn't arrive through a bridge device, this packet won't match this option, unless '!' is used. .TP .BR --physdev-out " [!] \fIname\fP" Name of a bridge port via which a packet is going to be sent (for packets entering the .BR FORWARD , .B OUTPUT and .B POSTROUTING chains). If the interface name ends in a "+", then any interface which begins with this name will match. Note that in the .BR nat " and " mangle .B OUTPUT chains one cannot match on the bridge output port, however one can in the .B "filter OUTPUT" chain. If the packet won't leave by a bridge device or it is yet unknown what the output device will be, then the packet won't match this option, unless '!' is used. .TP .RB "[!] " --physdev-is-in Matches if the packet has entered through a bridge interface. .TP .RB "[!] " --physdev-is-out Matches if the packet will leave through a bridge interface. .TP .RB "[!] " --physdev-is-bridged Matches if the packet is being bridged and therefore is not being routed. This is only useful in the FORWARD and POSTROUTING chains.