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
HP-UX IPFilter and IPSec
Allowing Protocol 50 and Protocol 51 Traffic
Chapter 9 133
If the IPFilter configuration is so broad that it blocks protocol 50 or
protocol 51 traffic, then IPSec traffic will not get through.
Figure 9-7 Scenario Four
In Scenario Four, IPSec is configured to encrypt TCP traffic between the
two machines and IPFilter is configured to block non-TCP traffic.
IPFilter rules are also configured to let UDP/500 traffic pass on
machine B.
# IPSec hole with machine B
pass in quick proto UDP from 15.15.15.15 port 500 to
10.10.10.10 port = 500
pass out quick proto UDP from 10.10.10.10 port 500 to
15.15.15.15 port = 500
# Let in encrypted IPSec traffic
pass in quick proto 50 from 15.15.15.15 to 10.10.10.10
pass out quick proto 50 from 10.10.10.10 to 15.15.15.15
# Allow TCP traffic to/from anywhere
pass in quick proto TCP
pass out quick proto TCP
# Block all other traffic to/from anywhere
block in from any to any
block out from any to any
NOTE If IPSec is configured to use AH rather than ESP, you must configure
IPFilter to let protocol 51 traffic pass. If IPSec uses nested AH and ESP,
IPFilter can be configured to let only protocol 51 (ah) traffic pass.
IPSec <---------------> TCP <-----------------> IPSec
A
B
10.10.10.10
15.15.15.15
IPFilter
-----block !TCP-----