3com 2200 Manual Do Utilizador

A

PPENDIX

 A: P

ACKET

 F

ILTER

 O

PCODES

, E

XAMPLES

, 

AND 

S

YNTAX

 E

RRORS

This filter accepts only frames whose source and destination address are in 
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

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