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NG_CISCO(4)	       FreeBSD Kernel Interfaces Manual		   NG_CISCO(4)

NAME
     ng_cisco -- Cisco HDLC protocol netgraph node type

SYNOPSIS
     #include <sys/types.h>
     #include <netinet/in.h>
     #include <netgraph/ng_cisco.h>

DESCRIPTION
     The cisco node type performs encapsulation	and de-encapsulation of	pack-
     ets using the Cisco HDLC protocol.	 This is a fairly simple protocol for
     the transmission of packets across	high speed synchronous lines.  Each
     packet is prepended with an Ethertype, indicating the protocol.  There is
     also a ``keep alive'' and an ``inquire'' capability.

     The downstream hook should	connect	to the synchronous line.  On the other
     side of the node are the inet, inet6, atalk, and ipx hooks, which trans-
     mit and receive raw IP, IPv6, AppleTalk, and IPX packets, respectively.
     Typically these hooks would connect to the	corresponding hooks on an
     ng_iface(4) type node.

IP Configuration
     In	order to function properly for IP traffic, the node must be informed
     of	the local IP address and netmask setting.  This	is because the proto-
     col includes an ``inquire'' packet	which we must be prepared to answer.
     There are two ways	to accomplish this, manually and automatically.

     Whenever such an inquire packet is	received, the node sends a
     NGM_CISCO_GET_IPADDR control message to the peer node connected to	the
     inet hook (if any).  If the peer responds,	then that response is used.
     This is the automatic method.

     If	the peer does not respond, the node falls back on its cached value for
     the IP address and	netmask.  This cached value can	be set at any time
     with a NGM_CISCO_SET_IPADDR message, and this is the manual method.

     If	the inet hook is connected to the inet hook of an ng_iface(4) node, as
     is	usually	the case, then configuration is	automatic as the ng_iface(4)
     understands the NGM_CISCO_GET_IPADDR message.

HOOKS
     This node type supports the following hooks:

     downstream	  The connection to the	synchronous line.

     inet	  IP hook.

     inet6	  IPv6 hook.

     atalk	  AppleTalk hook.

     ipx	  IPX hook

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

     NGM_CISCO_SET_IPADDR
	  This command takes an	array of two struct in_addr arguments.	The
	  first	is the IP address of the corresponding interface and the sec-
	  ond is the netmask.

     NGM_CISCO_GET_IPADDR
	  This command returns the IP configuration in the same	format used by
	  NGM_CISCO_SET_IPADDR.	 This command is also sent by this node	type
	  to the inet peer whenever an IP address inquiry packet is received.

     NGM_CISCO_GET_STATUS
	  Returns a struct ngciscostat:

	      struct ngciscostat {
		u_int32_t   seq_retries;       /* # unack'd retries */
		u_int32_t   keepalive_period;  /* in seconds */
	      };

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_iface(4), ngctl(8)

     D.	Perkins, Requirements for an Internet Standard Point-to-Point
     Protocol, RFC 1547.

LEGAL
     Cisco is a	trademark of Cisco Systems, Inc.

HISTORY
     The ng_cisco node type was	implemented in FreeBSD 4.0.

AUTHORS
     Julian Elischer <julian@FreeBSD.org>,
     Archie Cobbs <archie@FreeBSD.org>

BUGS
     Not all of	the functionality has been implemented.	 For example, the node
     does not support querying the remote end for its IP address and netmask.

FreeBSD	10.1		       January 19, 1999			  FreeBSD 10.1

NAME | SYNOPSIS | DESCRIPTION | IP Configuration | HOOKS | CONTROL MESSAGES | SHUTDOWN | SEE ALSO | LEGAL | HISTORY | AUTHORS | BUGS

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