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
Firewall Building Concepts
Improving Performance with Rule Groups
Chapter 5 81
block in log quick on lan0 from any to 20.20.20.255/32 group 1
pass in on lan0 all group 1
pass out on lan0 all
block out quick on lan1 all head 10
pass out quick on lan1 proto tcp from any to 20.20.20.64/26
port = 80 flags S keep state group 10
pass out quick on lan1 proto tcp from any to 20.20.20.64/26
port = 21 flags S keep state group 10
pass out quick on lan1 proto tcp from any to 20.20.20.64/26
port = 20 flags S keep state group 10
pass out quick on lan1 proto tcp from any to 20.20.20.65/32
port = 53 flags S keep state group 10
pass out quick on lan1 proto udp from any to 20.20.20.65/32
port = 53 keep state group 10
pass out quick on lan1 proto tcp from any to 20.20.20.66/32
port = 53 flags S keep state group 10
pass out quick on lan1 proto udp from any to 20.20.20.66/32
port = 53 keep state group 10
For a host on the lan2 network, IPFilter bypasses all the rules in group
10 when a packet is not destined for hosts on that network.
Multi-level grouping is also supported, allowing IPFilter rules to be
arranged in hierarchical, nested groups. By using the head and group
keywords in a rule, multi-level grouping allows the user to fine tune a
range to improve performance. The following is an example of a
multi-level rule grouping:
pass in proto tcp from 1.0.0.0-9.0.0.0 to any port = 23 keep
state head 1
pass in proto tcp from 2.0.0.0-8.0.0.0 to any port = 23 keep
state head 2 group 1
pass in proto tcp from 3.0.0.0-7.0.0.0 to any port = 23 keep
state head 3 group 2
pass in proto tcp from 4.0.0.0-6.0.0.0 to any port = 23 keep
state head 4 group 3
pass in proto tcp from 5.0.0.0-5.5.0.0 to any port = 23 keep
state group 4
You can group your rules by protocol, machine, netblock, or other logical
criteria that help system performance. There is not a hard limit to the
number of group levels you can maintain. For more information, see
Appendix C, “Performance Guidelines,” on page 179.