netgraph node type allows
interfaces to interact with
module is loaded in the kernel, a node is automatically created
interface in the system.
Each node will attempt to name itself with the same name
as the associated interface.
nodes are persistent for as long as the interface itself exists.
Two hooks are supported:
The hook name
may be used as an alias for
and is provided for compatibility with
In reality the two names represent the same hook.
hook is a connection to the raw
When connected, all incoming packets are diverted out this hook.
Writing to this hook results in a raw encapsulated packet being transmitted
by the device.
Normal outgoing packets are not affected by
hook is equivalent to
except that only unrecognized packets (that would otherwise be discarded)
are written to the hook, and normal incoming traffic is unaffected.
At most one of
may be connected at any time.
In all cases, frames are raw packets with the address family of the
packet attached to the front.
When no hooks are connected, packets flow normally upwards and downwards.