ng_rfc1490(4) RFC 1490 netgraph node type


In netgraph/ng_rfc1490.h


The rfc1490 node type performs protocol encapsulation, de-encapsulation, and multiplexing according to RFC 1490 (which has since been updated by RFC 2427). This particular type of encapsulation is often used on top of frame relay DLCI channels.

The downstream hook is used to transmit and receive encapsulated frames. On the other side of the node, the inet and ppp hooks are used to transmit and receive raw IP frames and PPP frames, respectively. PPP frames are transmitted and received according to RFC 1973; in particular, frames appearing on the ppp hook begin with the PPP protocol number. The ethernet hook can be used to transmit and receive Ethernet frames (without a checksum) in RFC 1490's bridging format.

Typically the inet hook is connected to the inet hook of an ng_iface4 node.


This node type supports the following hooks:

Connects to the RFC 1490 peer entity.
Transmits and receives bridged raw Ethernet frames, without a checksum.
Transmits and receives raw IP frames.
Transmits and receives PPP frames.


This node type supports the generic control messages, plus the following:

NGM_RFC1490_SET_ENCAP (setencap )
This command sets encapsulation method for the node. The desired method must be passed as a string message argument, and must be one of the following supported encapsulation modes:

Qq ietf-ip
IP packets are sent using simple RFC1490/2427 encapsulation.
Qq ietf-snap
IP packets are sent inside SNAP frames. Also conforms to RFC1490/2427.
Qq cisco
IP packets are sent and received using proprietary Cisco encapsulation method.

NGM_RFC1490_GET_ENCAP (getencap )
This command returns current encapsulation method on the node.


This node shuts down upon receipt of a NGM_SHUTDOWN control message, or when all hooks have been disconnected.


The node type was implemented in Fx 4.0 .


An Julian Elischer Aq [email protected]


Not all of RFC 1490 is implemented.