Zhone 2004 ユーザーガイド

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2 0 0 0 - A 2 - G B 2 2 - 0 0
Figure 4.55
DuSLIC Mode Selection Menu 
2
Type the option of the control mode to set. The IAD saves the mode you’ve 
selected and redisplays the menu.
3
Press Escape to return to the Voice Configuration menu and continue with 
other voice path configuration.
Firewall Configuration
Firewall configuration (also known as IP filtering) allows you to specify a 
combination of parameters the IAD uses to selectively eliminate IP traffic.
Refer to the IP Filtering Application Note contained in Appendix C.
Creating a Firewall via IP Filtering and NAT
IP Filtering, in conjunction with NAT, can provide a Firewall for securing the 
local network from unwanted and possibly harmful traffic. By defining a set 
of rules (IP Filtering) and open ports (NAT), you may selectively block traffic 
and deny access to the local network.
IP Filtering controls IP traffic traveling through an interface by selectively 
passing or discarding IP packets based on criteria expressed in the form of a 
“filter.” A filter is simply a set of rules that determine whether a packet 
should be passed or discarded as it crosses an interface. An interface is any 
port that carries IP traffic. On the IAD, it can be one of the following: 
Ethernet port, PPP connection, or ATM PVC.
IP Filtering can selectively pass or discard IP packets based on one or more of 
the following properties:
Protocol (IP, ICMP, TCP, and UDP)
Protocol flags (for TCP and ICMP only)
Source and/or Destination IP address
Source and/or Destination port number
For more information on defining and using a filter rule set, see IP Filtering 
Application note on page C-4.
For more information, see Configure IP Filtering on page 4-25.