Chapter 3. Installing Red Hat Linux

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3.22. Firewall Configuration

Red Hat Linux offers firewall protection for enhanced system security. A firewall exists between your

computer and the network, and determines which resources on your computer remote users on the

network can access. A properly configured firewall can greatly increase the security of your system.

Figure 3 19. Firewall Configuration

Choose the appropriate security level for your system.

High

If you choose High, your system will not accept connections (other than the default settings) that

are not explicitly defined by you. By default, only the following connections are allowed:

DNS replies

DHCP   so any network interfaces that use DHCP can be properly configured

If you choose High, your firewall will not allow the following:

Active mode FTP (passive mode FTP, used by default in most clients, should still work)

IRC DCC file transfers

RealAudio 

Remote X Window System clients

If you are connecting your system to the Internet, but do not plan to run a server, this is the safest

choice. If additional services are needed, you can choose Customize to allow specific services

through the firewall.

Note

If you select a medium or high firewall to be setup during this installation, network authentication

methods (NIS and LDAP) will not work.