Figure 7.20: Firewall Configuration Tcp Protocol Fields And Menu Options - Avocent Cyclades ACS Installation/Administration/User Manual

102 Cyclades ACS Advanced Console Server Installation, Administration and Users Guide
Inverted checkboxes
If the Inverted checkbox is enabled for the corresponding option, the target action is performed on
packets that do not match any of the criteria specified in that line.
For example, you select DROP as the target action from the Target pull-down list, check Inverted
on the line with the Source IP and do not specify any other criteria in the rule, any packets arriving
from any other source IP address than the one specified are dropped.
Target pull-down menu options
The Target pull-down menu shows the action to be performed on an IP packet that matches all the
criteria specified in a rule. The kernel can be configured to ACCEPT, DROP, RETURN, LOG or
REJECT the packet by sending a message, translating the source or the destination IP address or
sending the packet to another user-defined chain.
Source or destination IP and mask
If you add a value in the Source IP field, incoming packets are filtered for the specified IP address
and if you add a value in the Destination IP field, outgoing packets are filtered for the specified IP
address. A value in the Mask field means incoming or outgoing packets are filtered for IP addresses
from the network in the specified subnet.
Protocol
You can select a protocol for filtering. Fields that appear for each protocol are explained in the
following sections.
Numeric protocol fields
If Numeric is selected as the protocol when specifying a rule, a text field appears to the right of the
menu for the desired number.
TCP protocol fields
If TCP is selected as the protocol when specifying a rule, the additional fields shown in the
following figure appear on the bottom of the form.

Figure 7.20: Firewall Configuration TCP Protocol Fields and Menu Options