làm thế nào để duy trì hệ thống tập tin của bạn, và làm thế nào để phục hồi và vượt qua vấn đề Thời gian tốt nhất để đối phó với một vụ tai nạn hệ thống IS Trước khi tai nạn xảy ra. Điều này có nghĩa là | TCP IP Network Management 259 Chapter 13 At the very least you need to have the entries for Localhost Your NIS server Any systems from which you NFS mount disks The host itself In this example localhost is the first line followed by vestax your WWW server. mailhub is the machine with which sendmail communicates for mail and finally there is technics the name of the machine from which the etc hosts file came. Configuring the DNS Client etc Every machine in your network is a DNS client. In order to know which DNS server to use you need to configure the etc file. This file should look something like search nameserver where is the domain name of your site and the IP address listed after nameserver is the address of the DNS server with which you will be communicating. You can have up to three nameserver entries each of which will be tried sequentially until one of them returns an answer. 13 NOTE You must supply the nameserver s IP address not its hostname. After all how is the resolver going to know what the nameserver s IP address is until it finds the nameserver The Software of DNS While configuring DNS for your site you will need to be familiar with the following tools named The resolver library nslookup traceroute named is the daemon that needs to run on DNS servers to handle queries. If it cannot answer a query it is its responsibility to forward the request on to a server that can. Along with queries named is responsible for performing zone transfers. Zone transferring is the method by which changed DNS information is propagated across the Internet. You will need to install the named daemon from the BIND distribution available from http or on the CD-ROM that comes with this book filename . tcp ip Network Management 260 Hardware Connectivity and Devices Part III The resolver library enables client programs to perform DNS queries. This library is built into the standard
