Sams Teach Yourself TCP/IP in 24 Hours, Third Edition

DNS Name Resolution

The designers of DNS wanted to avoid having to keep an up-to-date name resolution file on each computer. DNS instead places name resolution data on one or more special servers. The DNS servers provide name resolution services for the network (see Figure 11.2). If a computer on the network encounters a hostname where it is expecting an IP address, it sends a query to the server asking for the IP address associated with the hostname. If the DNS server has the address, it sends the address back to the requesting computer. The computer then invisibly substitutes the IP address for the hostname and executes the command. When a change occurs on the network (such as a new computer or a change to a hostname), the network administrator ...