3Com 2200 manual

A-12 APPENDIX A: PACKET FILTER OPCODES, EXAMPLES, AND SYNTAX ERRORS

Address Group This filter accepts only frames whose source and destination address are in Filter the same group.

name	“Forward Same Source and Destination”
pushSAGM		#	Get source address group mask
pushDAGM		#	Get destination address group
		#	mask
and		#	Compare if source and
destination		#	groups are common members of
		#	an address group (result is
		#	either zero or non-zero)
		#	address group masks
pushLiteral.l	0	#	Put a zero on the stack
ne		#	If not equal, returns a “one”
		#	to stack, resulting in packet
		#	forwarded

Port Group Filter This filter discards all frames sourced from a port in either group three or eight.

name	“Discard	Port Groups 3 and 8”
pushSPGM		#	Get source port group mask
pushLiteral.l	0x0084	#	Select bits 3 and 8
and		#	If port group bits 3 & 8 are
		#	common with SPGM, then
		# non-zero value is
		#	pushed onto stack
pushLiteral.l	0	#	Push zero
eq		#	Only if SPGM is not in port
		#	groups corresponding to bits
		#	3 & 8, then packet is
		#	forwarded