An iface node is both a netgraph node and a system networking interface. When an iface node is created, a new interface appears which is accessible via ifconfig(8). Iface node interfaces are named ng0, ng1, etc. When a node is shutdown, the corresponding interface is removed and the interface name becomes available for reuse by future iface nodes; new nodes always take the first unused interface. The node itself is assigned the same name as its interface, unless the name already exists, in which case the node remains unnamed.
An iface node has a single hook corresponding to each supported protocol. Packets transmitted via the interface flow out the corresponding protocol-specific hook. Similarly, packets received on a hook appear on the interface as packets received into the corresponding protocol stack. The currently supported protocols are IP, IPv6, AppleTalk, IPX, ATM, NATM, and NS.
An iface node can be configured as a point-to-point interface or a broadcast interface. The configuration can only be changed when the interface is down. The default mode is point-to-point.
Iface nodes support the Berkeley Packet Filter (BPF).
This node type supports the following hooks: