ZyXEL Communications P-2602R-DxA Series - Manual (Page 16)

P-2602R/RL-DxA Series User’s Guide
16 Table of Contents
12.4.1 Basics ...................................................................................................151
12.4.2 Types of DoS Attacks ...........................................................................152
12.4.2.1 ICMP Vulnerability ......................................................................154
12.4.2.2 Illegal Commands (NetBIOS and SMTP) ....................................154
12.4.2.3 Traceroute ...................................................................................155
12.5 Stateful Inspection ..........................................................................................155
12.5.1 Stateful Inspection Process ..................................................................156
12.5.2 Stateful Inspection on Your ZyXEL Device ...........................................156
12.5.3 TCP Security .........................................................................................157
12.5.4 UDP/ICMP Security ..............................................................................157
12.5.5 Upper Layer Protocols ..........................................................................158
12.6 Guidelines for Enhancing Security with Your Firewall ....................................158
12.6.1 Security In General ...............................................................................158
12.7 Packet Filtering Vs Firewall ............................................................................159
12.7.1 Packet Filtering: ....................................................................................159
12.7.1.1 When To Use Filtering .................................................................160
12.7.2 Firewall .................................................................................................160
12.7.2.1 When To Use The Firewall ..........................................................160
Chapter 13
Firewall Configuration ......................................................................................... 161
13.1 Access Methods .............................................................................................161
13.2 Firewall Policies Overview ............................................................................161
13.3 Rule Logic Overview .....................................................................................162
13.3.1 Rule Checklist .......................................................................................162
13.3.2 Security Ramifications ..........................................................................162
13.3.3 Key Fields For Configuring Rules .........................................................163
13.3.3.1 Action ..........................................................................................163
13.3.3.2 Service ........................................................................................163
13.3.3.3 Source Address ...........................................................................163
13.3.3.4 Destination Address ....................................................................163
13.4 Connection Direction ......................................................................................163
13.4.1 LAN to WAN Rules ...............................................................................164
13.4.2 Alerts .....................................................................................................164
13.5 General Firewall Policy ...............................................................................164
13.6 Firewall Rules Summary ...............................................................................165
13.6.1 Configuring Firewall Rules ...................................................................167
13.6.2 Customized Services ............................................................................170
13.6.3 Configuring A Customized Service ......................................................171
13.7 Example Firewall Rule ...................................................................................171
13.8 DoS Thresholds ............................................................................................175
13.8.1 Threshold Values ..................................................................................175
13.8.2 Half-Open Sessions ..............................................................................176