tailieunhanh - DNS and BIND 5th Edition_10

Tham khảo tài liệu 'dns and bind 5th edition_10', công nghệ thông tin, hệ điều hành phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | DNS BIND -f DNS and BIND- C SEARCH Chapter 15 Miscellaneous Additional Resource Records There are a couple of resource records that we haven t covered yet in this book. The first of these has been around since the beginning HINFO but hasn t been widely used. The others were defined in RFC 1183 and several successive RFCs. Most are experimental but some are on the standards track and are coming into more prevalent use. We ll describe them here to give you a little head start in getting used to them. Host Information HINFO stands for Host INFOrmation. The data are a pair of strings identifying the host s hardware type and operating system. The strings should come from the MACHINE NAMES and OPERATING SYSTEM NAMES listed in the Assigned Numbers RFC currently RFC 1700 but this requirement is not enforced you can use your own abbreviations. The RFC isn t at all comprehensive so it is quite possible you won t find your system in the list anyway. Originally host information records were designed to let services like FTP determine how to interact with the remote system. This would have made it possible to negotiate data type transformations automatically. Unfortunately this didn t happen - few sites supply accurate HINFO values for all their systems. Some network administrators use HINFO records to help them keep track of the machine types instead of recording the machine types in a database or a notebook. Here are two examples of HINFO records note that the hardware type or operating system must be surrounded with quotes if it includes any whitespace These machine names and system names did not come from RFC 1340 wormhole IN HINFO ACME-HW ACME-GW cujo IN HINFO Watch Dog Hardware Rabid OS As we pointed out HINFO records are a security risk - by providing easily accessible information about a system you are making it easier for a hacker to break in. AFSDB AFSDB has a syntax like that of the MX record and semantics a bit like that of the NS record. An AFSDB