3Com LANPLEX 6000 User Manual page 207

4 Add an and statement to compare the results of step 2 with the results of
step 3:
and # compare if IP and in range
This combination would look like the following:
Name "Only IP pkts w/in socket range"
pushField.w 12
pushLiteral.w 0x0800
eq
pushLiteral.w 0x76c
pushField.w 24
ge
pushLiteral.w 0x0898
pushField.w 24
lt
and
and
Combining All the Filters. Together, the four packet filters work to
perform the solution to the problem: filtering the broadcast packets from
the market data servers. The steps below show how to create this filter:
1 Name the filter:
"Discard XNS & IP pkts w/in socket range"
2 Go through steps 2 through 4 as described in "Packet Filter One" on
page 14-15.
3 Go through steps 2 through 8 as described in "Packet Filter Two" on
page 14-16.
4 Add an and statement to compare the results of step 2 and the results of
step 3:
and # compare if XNS & in range
Creating Packet Filters
# get the type field of the packet and
# place it on top of the stack
# put the type value for IP on top of
# the stack
# if the two values on the top of the
# stack are equal, then return a non-zero
# value
# put the lowest socket value on top of
# the stack (1900)
# put the value of the socket from the
# packet on top of the stack
# compare if the value of the socket is
# greater than or equal to the lower bound
# put the highest socket value on top of
# the stack (2200)
# put the value of the socket from the
# packet on top of the stack
# compare if the value of the socket is
# less than the upper bound
# "and" together with "ge" and "lt" test
# to determine if the socket value is
# "within" the range. If it is in range, a
# "one" will be placed on the stack.
# compare if IP and in range
14-17