ZyXEL Communications P-660H-T1 v2, Руководство пользователя

Страница: 127 / 312

Chapter 9 Firewall Configuration
P-660H-Tx v2 User’s Guide
127
The following table describes the labels in this screen.
9.6 Firewall Rules Summary
"
The ordering of your rules is very important as rules are applied in turn.
Refer to Section 8.1 on page 111 for more information.
Click Security > Firewall > Rules to bring up the following screen. This screen displays a list
of the configured firewall rules. Note the order in which the rules are listed.
Table 38 Firewall: General
LABEL DESCRIPTION
Active Firewall Select this check box to activate the firewall. The ZyXEL Device performs access
control and protects against Denial of Service (DoS) attacks when the firewall is
activated.
Bypass Triangle
Route
Select this check box to have the ZyXEL Device firewall permit the use of triangle
route topology on the network. See the appendix for more on triangle route
topology.
Note: Allowing asymmetrical routes may let traffic from the WAN go
directly to a LAN computer without passing through the
router. See
Appendix H on page 297 for more on triangle
route topology and how to deal with this problem.
Packet Direction This is the direction of travel of packets ( LAN to LAN / Router , LAN to WAN ,
WAN to WAN / Router , WAN to LAN) .
Firewall rules are grouped based on the direction of travel of packets to which they
apply. For example, LAN to LAN / Router means packets traveling from a
computer/subnet on the LAN to either another computer/subnet on the LAN
interface of the ZyXEL Device or the ZyXEL Device itself.
Default Action Use the drop-down list boxes to select the default action that the firewall is take on
packets that are traveling in the selected direction and do not match any of the
firewall rules.
Select
Drop to silently discard the packets without sending a TCP reset packet or
an ICMP destination-unreachable message to the sender.
Select
Reject to deny the packets and send a TCP reset packet (for a TCP
packet) or an ICMP destination-unreachable message (for a UDP packet) to the
sender.
Select
Permit to allow the passage of the packets.
Log Select the check box to create a log (when the above action is taken) for packets
that are traveling in the selected direction and do not match any of your
customized rules.
Expand... Click this button to display more information.
Basic... Click this button to display less information.
Apply Click Apply to save your changes to the ZyXEL Device.
Cancel Click Cancel to begin configuring this screen afresh.