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Echo LANlink Router Option User Manual
Issue 1.0
04 December 1997 Page 40 of 59
4.7.4 IPX HEADER FILTERS
There is a single IPX header filter that can control the forwarding of packets
from each port. The user can select if this filter is applied to packets received
from either or both ports.
from each port. The user can select if this filter is applied to packets received
from either or both ports.
The filter can have up to 128 entries. If IPX filtering is active, then any
packets received are checked against the filter table before processing by the
Router. The operation of the IPX filter does not effect RIP and SAP packets
as they are processed directly by the Router.
packets received are checked against the filter table before processing by the
Router. The operation of the IPX filter does not effect RIP and SAP packets
as they are processed directly by the Router.
It should be noted that the filter table is sequentially searched for each IPX
packet received until a match is found. A filter table with multiple entries will
impose a significant processor loading and a corresponding drop in
performance.
packet received until a match is found. A filter table with multiple entries will
impose a significant processor loading and a corresponding drop in
performance.
In most cases IPX conversations require packets to be passed in both
directions. Stopping packet flow in one direction will stop any conversation
taking place. It may not be necessary to use filters in both directions.
directions. Stopping packet flow in one direction will stop any conversation
taking place. It may not be necessary to use filters in both directions.
The filter table is configured depending upon which networks, nodes and
sockets are expected to be found connected to each port. The actual
comparison of the packet source or destination address in the IPX Header to
the filter table changes depending upon which port the packet is received
from. If network 45 is set by the filter as connected to Port A then packets
received from Port A would have the IPX header source network number
compared to the entry for network 45. Packets received from Port B would
have the IPX header destination network number compared to 45.
sockets are expected to be found connected to each port. The actual
comparison of the packet source or destination address in the IPX Header to
the filter table changes depending upon which port the packet is received
from. If network 45 is set by the filter as connected to Port A then packets
received from Port A would have the IPX header source network number
compared to the entry for network 45. Packets received from Port B would
have the IPX header destination network number compared to 45.
Each of the seven fields can be set to pass ALL. The result of any entry can
be set to PASS or FAIL. If the search reaches the end of the table with no
match then the result is an automatic FAIL.
be set to PASS or FAIL. If the search reaches the end of the table with no
match then the result is an automatic FAIL.
MENU SELECTION
DESCRIPTION
ADD
A new entry may be added to the end
of the Table or after an entry
of the Table or after an entry
EDIT
To edit an entry, selecting the
relevant line number entering
required amendments.
relevant line number entering
required amendments.
DELETE
Enter the line number to delete.
CLEAR
To delete the entire table.
NAME
Define a name for this filter table
LIST PARAMETER
DESCRIPTION
LINE
The Line Number of the Filter Table
entry used to specify an entry to be
changed or deleted.
entry used to specify an entry to be
changed or deleted.