Programmable Filtering
IOLINK-PRO & 520 Reference Manual —

B.13

IP Router Pattern Filtering
Pattern filtering may be used on any portion of the IP frame. IP pattern filtering behaves the same as bridge pattern filtering,
except the start of the IP frame is offset 0, because the IP router function of the bridge/router handles only the IP frame
itself.
IP pattern filtering may use any combination of filtering operators as described in the bridge pattern filters.

Protocol Discrimination

Protocol discrimination may be required to prevent or limit the protocols within an IP frame that may traverse a routed Local
Area Network.
In Local Area Networks, there may be many different Transport layer protocols that coexist within the IP Network layer .
TCP, UDP, and ICMP are just a few of the common protocols in use today. Each of these protocols is encapsulated within
an IP frame, and therefore is subject to the IP routing function. If you would like to discriminate against a particular protocol
to prevent its usage of the routed LAN facilities the IOLINK-PRO & 520 Router provides programmable filter masks that
may be defined to act on any part of the IP frame.
The IP Router Filter Patterns menu is located under the Filter Set-Up Menu. Within the IP Router Filter Patter ns Menu there
exists a Help function that can be used as a reference during IP Router Filter Pattern creation. This Help function includes all
of the logical operators that may be applied to the mask expression.
IPX Router Pattern Filtering
Pattern filtering may be used on any portion of the IPX frame. IPX pattern filtering behaves the same as bridge pattern
filtering, except the start of the IPX frame is offset 0, because the IPX router function of the bridge/router handles only the
IPX frame itself.
IPX pattern filtering may use any combination of filtering operators as described in the bridge pattern filters.
The IPX Router Filter Patterns menu is located under the Filter Set-Up Menu. Within the IPX Router Filter Patterns Menu,
there exists a Help function that can be used as a reference during IPX Router Filter Pattern creation. This Help function
includes all of the logical operators that may be applied to the mask expression.