NAME
ng_rfc1490 —
RFC 1490 netgraph node type
SYNOPSIS
#include
<netgraph/ng_rfc1490.h>
DESCRIPTION
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_iface(4) node.
HOOKS
This node type supports the following hooks:
- downstream
- Connects to the RFC 1490 peer entity.
- ethernet
- Transmits and receives bridged raw Ethernet frames, without a checksum.
- inet
- Transmits and receives raw IP frames.
- ppp
- Transmits and receives PPP frames.
CONTROL MESSAGES
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:
- "
ietf-ip" - IP packets are sent using simple RFC1490/2427 encapsulation.
- "
ietf-snap" - IP packets are sent inside SNAP frames. Also conforms to RFC1490/2427.
- "
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.
SHUTDOWN
This node shuts down upon receipt of a
NGM_SHUTDOWN control message, or when all hooks have
been disconnected.
SEE ALSO
netgraph(4), ng_frame_relay(4), ng_iface(4), ngctl(8)
C. Brown and A. Malis, Multiprotocol Interconnect over Frame Relay, RFC 2427.
W. Simpson, PPP in Frame Relay, RFC 1973.
http://www.cisco.com/warp/public/121/frf8modes.pdf
HISTORY
The ng_rfc1490 node type was implemented
in FreeBSD 4.0.
AUTHORS
Julian Elischer <julian@FreeBSD.org>
BUGS
Not all of RFC 1490 is implemented.