System information

Web Manager "Network" Menu Options 269
Configuring Firewall Rules for OnBoard Packet Filtering
Figure 8-5 shows the six built-in chains. The rules for the built-in chains are
hidden. The top three chains are defined in the iptables “filter” table and
the bottom three chains are defined in the iptables “nat” table. Also as
shown, an “Add new table_name chain_name rule” button appears under the
entry for each chain, for example, “Add new NAT prerouting rule.”
Administrative users may want to add rules to the default chains to suit their
environment and their needs. The example in Figure 8-5 shows an example of
an administratively-defined rule for the filter table INPUT chain. The number
0 is assigned automatically. As shown, an “Edit” and “Delete” button appear
next to the entry for each administrator-defined rule.
The administrative user can use the “Edit,” “Delete,” and “Add new
table_name chainname rule” buttons on the form to do the following:
•Add new rules
• Edit administrator-added rules
• Delete administrator-added rules
Adding a Rule
Clicking an “Add new table_name chainname rule” button brings up a dialog
like the one shown in the following figure, which shows the dialog that
appears when the administrative user clicks the “Add new NAT prerouting
rule” button.
Figure 8-6: Network → Firewall: Add Rule Dialog
See Table 1-25, “Filter Options for Packet Filtering Rules,” on page 57 for
definitions of the filter options on the dialog shown in Figure 8-6.