Table of Contents
13.3.3 Call Forwarding ......................................................................................................
228
13.3.4 Follow Me ...............................................................................................................
13.3.5 Call Pickup .............................................................................................................
229
13.4
Checking the Device’s IP Address ...................................................................................
13.5
Auto Firmware Upgrade ..................................................................................................
Part V: Security ....................................................................................
231
Chapter 14
Firewalls.................................................................................................................................
233
14.1
Firewall Overview ...........................................................................................................
14.2
Types of Firewalls ............................................................................................................
14.2.1 Packet Filtering Firewalls .......................................................................................
14.2.2 Application-level Firewalls ......................................................................................
234
14.2.3 Stateful Inspection Firewalls ..................................................................................
14.3
Introduction to ZyXEL’s Firewall ......................................................................................
14.3.1 Denial of Service Attacks .......................................................................................
235
14.4
Denial of Service .............................................................................................................
14.4.1 Basics .....................................................................................................................
14.4.2 Types of DoS Attacks .............................................................................................
236
14.5
Stateful Inspection ...........................................................................................................
238
14.5.1 Stateful Inspection Process ....................................................................................
239
14.5.2 Stateful Inspection on Your ZyXEL Device .............................................................
240
14.5.3 TCP Security ..........................................................................................................
14.5.4 UDP/ICMP Security ................................................................................................
241
14.5.5 Upper Layer Protocols ...........................................................................................
14.6
Guidelines for Enhancing Security with Your Firewall .....................................................
242
14.6.1 Security In General ................................................................................................
14.7
Packet Filtering Vs Firewall .............................................................................................
243
14.7.1 Packet Filtering: .....................................................................................................
14.7.2 Firewall ...................................................................................................................
Chapter 15
Firewall Configuration ..........................................................................................................
245
15.1
Access Methods ..............................................................................................................
15.2
General Firewall Policy Overview ...................................................................................
15.3
Rule Logic Overview .......................................................................................................
246
15.3.1 Rule Checklist ........................................................................................................
15.3.2 Security Ramifications ............................................................................................
15.3.3 Key Fields For Configuring Rules ..........................................................................
247
15.4
Connection Direction .......................................................................................................
17
P-2602HWLNI User’s Guide