Synopses & Reviews
A modern computer system that is not part of a network is an anomaly. But managing a network and getting it to perform well can be a problem. This book describes two tools that are absolutely essential to distributed computing environments: the Network Filesystem (NFS) and the Network Information System (formerly called the "yellow pages" or YP).The Network Filesystem, developed by Sun Microsystems, is fundamental to most UNIX networks. It allows systems ranging from PCs running DOS to UNIX workstations to large mainframes to access each other's files transparently. It is the standard method for sharing files between different computer systems.As popular as NFS is, it is a "black box" for most users and administrators. This book provides a comprehensive discussion of how to plan, set up, and debug an NFS network. It is the only book we're aware of that discusses NFS and network performance tuning. This book also covers the NFS automounter, network security issues, diskless workstations, and PC/NFS.NFS isn't really complete without its companion, NIS. NIS provides a distributed database service for managing the most important administrative files, such as the passwd file and the hosts file. NIS centralizes administration of commonly replicated files, letting you make a single change to the database rather than making changes on every system on the network.This book tells you how to set up and use NIS to simplify network management. It also tells you how to use NIS to manage your own database applications, ranging from a simple telephone list to controlling access to network services.If you are managing a network of UNIX systems, or are thinking of setting up a UNIX network, you can't afford to overlook this book.
Synopsis
For system administrators who need to set up or manage a network file system installation. This is the only practical book devoted entirely to NFS (Network Filesystem) and NIS (Network Information System)--a must-have for anyone interested in UNIX networking.
About the Author
Hal Stern is a technical consultant with Sun Microsystems, where he specializes in networking, performance tuning, and kernel hacking. Hal earned a Bachelor of Science degree from Princeton University in 1984. Before joining Sun, Hal was a member of the technical staff at Polygen Corporation, developing UNIX-based molecular modelling and chemical information system products. Hal also worked on the Massive Memory Machine project as a member of the Research Staff in Princeton University's Department of Computer Science. His interests include large installation system administration, virtual memory management systems, performance, local and wide-area networking, interactive graphics, applications in financial services, cosmology, and the history of science. Hal is active in the Sun User's Group and has served on the advisory trustee board of the Princeton Broadcasting Service for seven years. Hal and his wife Toby live in Burlington, Massachusetts. At home, Hal enjoys carpentry, jazz music, cooking, and watching the stock market.
Table of Contents
Table of Contents
Who This Book is For
Versions
Organization
Conventions Used in This Book
Acknowledgments
Chapter 1. Networking Fundamentals
Networking Overview
Physical and Data Link Layers
Frames and Network Interfaces
Ethernet Addresses
Network Layer
Datagrams and Packets
IP Host Addresses
IP Address Classes
Transport Layer
TCP and UDP
Port Numbers
The Session and Presentation Layers
The Client-Server Model
External Data Representation
Internet and RPC Server Configuration
Chapter 2. Network Information Service Operation
Types of NIS Service
Basics of NIS Management
Installing the NIS Master Server
Installing NIS Slave Servers
Enabling NIS on Client Hosts
NIS Architecture
NIS Domains
Map Files
Map Naming
Map Structure
Files Managed Under NIS
Netgroups
Integrating NIS Maps
Overriding the NIS Password Map
NIS Server Operation
The ypserv Daemon
NIS Server as an NIS Client
Trace of a Key Match
Chapter 3. System Management Using the Network Information Service
NIS Network Design
Dividing a Network Into Domains
Domain Names
Number of NIS Servers per Domain
Managing Map Files
Map Distribution
Regular Map Transfers
Map File Dependencies
Password File Updates
Source Code Control For Map Files
Using Alternate Map Source Files
Advanced NIS Server Administration
Removing an NIS Slave Server
Changing NIS Master Servers
Domain Aliases
Managing Multiple Domains
Domain Name Servers
DNS versus NIS
DNS Integration with NIS
DNS Without NIS
NIS and DNS Domain Names
Multiple Service Integration
What Next?
Chapter 4. Building Applications with NIS
Locally Defined Maps
Building NIS Maps From ASCII Files
Modifying the NIS Makefile
Installing and Maintaining the Map
The phonelist Application
Using NIS For Information Distribution
The NIS Client Library
Integrating NIS Services Into Applications
Example: The Stock Quote Service
Chapter 5. System Administration Using the Network File System
Setting up NFS
Exporting Filesystems
Rules for Exporting Filesystems
Exporting Options
Mounting Filesystems
Using /etc/fstab
Using mount
Mount Options
Backgrounding Mounts
Hard and Soft Mounts
Resolving Mount Problems
Symbolic Links
Resolving Symbolic Links in NFS
Absolute and Relative Pathnames
Mount Points, Exports and Links
Chapter 6. Network File System Design and Operation
Virtual File Systems and Virtual Nodes
Chapter 7. Diskless Clients
NFS Support for Diskless Clients
Setting up a Diskless Client
Diskless Client Boot Process
Reverse ARP Requests
Getting a Boot Block
Booting a Kernel
Managing Client Swap Space
Changing a Client's Name
Troubleshooting
Missing and Inconsistent Client Information
Checking Boot Parameters
Missing /usr
Configuration Options
Dataless Clients
Swapping on a Local Disk
Client/Server Ratios
Chapter 8. Network Security
User-Oriented Network Security
Trusted Hosts and Trusted Users
Enabling Transparent Access
Using Netgroups
Password and NIS Security
Managing the Root Password With NIS
Making NIS More Secure
Intruder Alerts
NFS Security
NFS RPC Authentication
Superuser Mapping
Unknown User Mapping
Access to Filesystems
Read-Only Access
Port Checking
Secure RPC and Secure NFS
Encryption Techniques
How Secure RPC Works
Enabling Secure NFS
Public and Private Keys
Secure NFS Checklist
Kerberos
Viruses
Chapter 9. Centralizing Mail Services with NFS and NIS
Creating a Shared Mail Spool
Problems With Distributed Spool Directories
NFS Mounting the Mail Spool
Remote sendmail Execution
Mail Hub Forwarding Aliases
Mail Notification
Name Hiding
NIS Alias Expansion
Wide-Area Aliases
Setting Up A Distribution List
Handling Errors
Archiving and Management
Merging NIS and Local Aliases
Forwarding
Chapter 10. Diagnostic and Administrative Tools
Broadcast Addresses
MAC and IP Layer Tools
ifconfig: Interface Configuration
Subnetwork Masks
IP to MAC Address Mappings
Using ping to Check Network Connectivity
Gauging Ethernet Interface Capacity
Remote Procedure Call Tools
RPC Mechanics
RPC Registration
Debugging RPC Problems
NIS Tools
Key Lookup
Displaying and Analyzing Client Bindings
Other NIS Map Information
Modifying Client Bindings
NFS Tools
Displaying Mount Information
NFS Statistics
Time Synchronization
Chapter 11. Debugging Network Problems
Improper Network Termination
Duplicate ARP Replies
Renegade NIS Server
Boot Parameter Confusion
Interpreting NFS Error Messages
Chapter 12. Performance Analysis and Tuning
Characterization of NFS Behavior
Measuring Performance
Benchmarking
Identifying NFS Performance Bottlenecks
Problem Areas
Locating Bottlenecks
Network Congestion and Network Interfaces
Local Network Interface
Collisions and Network Saturation
Network Partitioning Hardware
Protocol Filtering
Partitioning With Bridges
Chapter 13. The Automounter
Automounter Maps
Indirect Maps
Inside the Automounter
Direct Maps
Invocation and the Master Map
The Master Map
Command Line Options
Tuning Timeout Values
Integration with NIS
Key and Variable Substitutions
Key Substitutions
Variable Substitutions
Advanced Map Tricks
Replicated Servers
Hierarchical Mounts
Conversion of Direct Maps
Subdirectory Fields
Side Effects
Long Search Paths
Local Mounts
Avoiding Automounted Filesystems
Pathname Cleanup
Shutting Down the Automounter
Chapter 14. PC/NFS
Configuring PC/NFS
PC Configuration
Starting PC/NFS
Server Configuration
Using PC/NFS
Mounting Filesystems
Checking File Permissions
Filename Mapping
Symbolic Links
UNIX to DOS file conversion
Printer Services
Choosing a Printer
Redirecting Printer Output
How PC/NFS Printing Works
Network Redirector Operation
PC/NFS Network Administration
Routing
Network Tools
PC/NFS Network and Mount Parameters
Appendix A. Transmission Line Theory
Appendix B. IP Packet Routing
Appendix C. NFS Problem Diagnosis
NFS Server Problems
NFS Client Problems
NFS errno values
Appendix D. NFS Benchmarks
Figures
1-1 Remote Procedure Call Execution
2-1 Trace of getpwuid() Library Call
3-1 Map Sharing in Multiple Domains
8-1 Client-Server Remote Logins
8-2 Exponential Key Exchange
10-1 Testing Relative Packet Handling Rates
11-1
11-2
11-3
11-4 Improper Thinnet Termination
12-1 Server Response Time Under Peak Load
12-2 Ideal vs Actual Server Response
12-3 Collision Rate Calculation
12-4
12-5 Computation of Average Collision Rates
A-1
A-2
A-3
A-4
A-5
A-6
A-7
A-8
A-9
A-10
B-1 ICMP Redirect Generation
Tables
1-1 The ISO 7-layer Model
1-2 IP Address Classes
2-1 Files Managed by NIS
3-1 Subdividing a DNS Domain into NIS Domains
5-1 NFS Export Options
7-1 Diskless Client Filesystem Locations
7-2 Diskless Client Filesystems on Two Disks
9-1 Exposed Host Names
10-1 AUTHOR TO PROVIDE TITLE
10-2 Broadcast Address Forms
10-3 Default Broadcast Addresses
10-4 Ethernet Address Prefixes
10-5 Mount Information Files
11-1 NFS-related errno values
12-1 Network Loading Thresholds
12-2 NFS Mount Weight Allocations
12-3 NFS Server Weights for Client suds
14-1 UNIX-to-DOS Filename Mapping
D-1 Legato NFS RPC Mixture
D-2 Dataless and Diskfull Client RPC Mixtures
D-3