HP-UX IPFilter A.03.05.13 Administrator's Guide: HP-UX 11i v3
Table Of Contents
- HP-UX IPFilter Version A.03.05.13 Administrator's Guide
- Legal Notices
- Table of Contents
- Preface: About This Document
- 1 Installing and Configuring HP-UX IPFilter
- Overview of HP-UX IPFilter Installation
- Step 1: Checking HP-UX IPFilter Installation Prerequisites
- Step 2: Loading HP-UX IPFilter Software
- Step 3: Determining the Rules for IPFilter
- Step 4: Adding Rules to the Rules Files
- Step 5: Loading IPFilter and NAT Rules
- Step 6: Verifying the Installation and Configuration
- Kernel Tunable Parameters
- Supported and Unsupported Interfaces
- Troubleshooting HP-UX IPFilter
- 2 HP-UX IPFilter on HP-UX 11i Version 3
- 3 Rules and Keywords
- IPFilter Configuration Files
- Basic Rules Processing
- IPFilter Keywords
- pass and block: Controlling IP Traffic
- in and out: Bidirectional Filtering
- quick: Optimizing IPFilter Rules Processing
- on: Filtering by Network Interfaces
- from and to: Filtering by IP Addresses and Subnets
- log: Tracking Packets on a System
- proto: Controlling Specific Protocols
- opt and ipopts: Filtering on IP Options
- icmp-type: Filtering ICMP Traffic by Type
- port: Filtering on TCP and UDP Ports
- keep state: Protecting TCP, UDP, and ICMP Sessions
- flags: Tight Filtering Based on TCP Header Flags
- keep frags: Letting Fragmented Packets Pass
- with frags: Dropping Fragmented Packets
- with short: Dropping Short Fragments
- return-rst: Responding to Blocked TCP Packets
- return-icmp: Responding to Blocked ICMP Packets
- dup-to: Drop-Safe Logging
- NAT Keywords
- 4 Dynamic Connection Allocation
- 5 Firewall Building Concepts
- Blocking Services by Port Number
- Using Keep State
- Using Keep State with UDP
- Using Keep State with ICMP
- Logging Techniques
- Improving Performance with Rule Groups
- Localhost Filtering
- Using the to
- Creating a Complete Filter by Interface
- Combining IP Address and Network Interface Filtering
- Using Bidirectional Filtering Capabilities
- Using port and proto to Create a Secure Filter
- 6 HP-UX IPFilter Utilities
- 7 HP-UX IPFilter and FTP
- 8 HP-UX IPFilter and RPC
- 9 HP-UX IPFilter and IPSec
- 10 HP-UX IPFilter and Serviceguard
- A HP-UX IPFilter Configuration Examples
- B HP-UX IPFilter Static Linking
- C Performance Guidelines
- Index

Dynamic Connection Allocation
DCA Rule Modifications
Chapter 468
2. Delete the old rule.
To Add a New Subnet or IP Address Range Rule:
1. Add the new rule on the line before the old rule which the new rule is
to replace.
2. Delete the old rule.
Limit entries made by the old rule are updated when a new
connection is processed. New connections are processed with the new
rule.
To add a more specific subnet or IP address range rule, see the
following section, Integrating keep limit Rules.
Integrating keep limit Rules
The following procedure describes how to add a specific subnet or IP
address range rule before an existing general subnet or IP address range
rule.
1. Add the new subnet or IP address range rule. Be sure to re-enter the
old subnet or IP address range rule exactly as it was entered before.
When a new connection matches an existing limit entry, the new
connection will be processed by the new subnet or IP address range
rule. The subnet or IP address range can be cumulative or
non-cumulative.
Extracting an Individual Rule from a Subnet Rule
To extract an individual rule from a subnet rule:
1. Add the new rule on the line before the subnet rule. Be sure the
subnet or IP address range rule is identical to the old rule.
When a new connection matches an existing limit entry, the new
connection will be processed by the new individual rule. The subnet
or IP address range can be cumulative or non-cumulative.