Intermec MobileLAN 21 Series System Manual page 88

MobileLAN access 21XX System Manual
Set the third filter expression as shown below.
The following table explains the values used in the third filter expression.
Parameter
ExprSeq
Offset
Mask
OP
Value ID
Action
The three expressions combine to form a single compound expression. The compound
expression forms an advanced filter that drops all DIX IP multicast frames except those
from the three Ethernet stations whose addresses are listed on the Filter Values menu.
The default action is always the opposite of the action specified in the last expression. In
this example, the action of the last expression is drop; therefore, the default action is
pass. Any frame that meets the conditions specified in the advanced filter is passed.
3-26
Value Explanation
3 This is the third expression.
6 The data for this expression begins at an offset of 6 bytes from
the beginning of the destination address. (Check the source
Ethernet address, in this example.)
ffffffffffff Check six bytes for an exact match.
NE Compare the value at the offset to the value specified on the
Filter Values menu to see if they are not equal. (Compare the
source Ethernet address with the list of Ethernet addresses from
the Filter Values menu.)
3 Use the value from the Filter Values menu whose value ID is 3.
Drop If the source Ethernet address does not match any address in the
list on the Filter Values menu, then drop the frame.