3Com 10014299 manual Configure Hdlc Display and Debug Hdlc, Display and debug Hdlc

18 CONFIGURING HDLC

	This chapter contains information on the following topics:
	■ Configure HDLC
	■ Display and Debug HDLC
Configure HDLC	HDLC (High Data Link Control) is a bit-oriented link layer protocol. Its most
	prominent feature is that it can transparently transmit any kind of bit flow without
	the restriction that the data must be character set. Protocols of standard HDLC
	protocol group operate upon the synchronous serial lines, e.g., DDN. The address
	field of HDLC is 8 bits, its control field is 8 bits, and the protocol field is 16 bits,
	which are used to represent all kinds of control information of HDLC protocol and
	to mark whether they are data. The 3Com Router supports the HDLC protocol and
	can connect with HDLC protocol of other popular devices.HDLC configuration
	includes:
	■ Configure the link layer protocol of the interface to HDLC
	1 Configure the Link Layer Protocol of the Interface to HDLC
	In synchronous interface view, perform the following task.
	Table 318 Configure the link layer protocol of the interface to HDLC
		Operation		Command
		Configure the link layer protocol of the interface to		link-protocol hdlc
		HDLC
	By default, the link layer protocol of the interface is PPP.
	Only when the interface operates in the synchronous mode, can the link layer
	protocol be configured to HDLC.
	When the interface link layer protocol is SLIP, its physical attribute cannot be
	changed to synchronous mode. At this time, you should first change the link layer
	protocol of the interface to PPP before you change the interface attribute to
	synchronous mode.
Display and Debug	Table 319 Display and debug HDLC
HDLC
		Operation	Command
		Enable all the debugging of HDLC protocol	debugging hdlc all [ interface
			type number ]
		Enable HDLC event debugging	debugging hdlc event [
			interface type number ]