ZyXEL Communications EMG5324-D10A ユーザーズマニュアル

Chapter 13 Firewall

EMG5324-D10A User’s Guide

Change the default password via web configurator.

Think about access control before you connect to the network in any way.

Limit who can access your Device.

Don't enable any local service (such as Telnet or FTP) that you don't use. Any enabled service could 
present a potential security risk. A determined hacker might be able to find creative ways to misuse 
the enabled services to access the firewall or the network.

For local services that are enabled, protect against misuse. Protect by configuring the services to 
communicate only with specific peers, and protect by configuring rules to block packets for the 
services at specific interfaces.

Keep the firewall in a secured (locked) room.

Note: Incorrectly configuring the firewall may block valid access or introduce security 

risks to the Device and your protected network. Use caution when creating or 

deleting firewall rules and test your rules after you configure them.

Consider these security ramifications before creating a rule:

Does this rule stop LAN users from accessing critical resources on the Internet? For example, if IRC 
is blocked, are there users that require this service?

Is it possible to modify the rule to be more specific? For example, if IRC is blocked for all users, will 
a rule that blocks just certain users be more effective?

Does a rule that allows Internet users access to resources on the LAN create a security 
vulnerability? For example, if FTP ports (TCP 20, 21) are allowed from the Internet to the LAN, 
Internet users may be able to connect to computers with running FTP servers.

Does this rule conflict with any existing rules?

Once these questions have been answered, adding rules is simply a matter of entering the 
information into the correct fields in the web configurator screens.