DNS BIND Linux教学课件.ppt

Cryptography DNS and BIND tcp/ip DHCP Relay 保留地址 libnss_files.so libnss_dns.so 100层 TLD: Top Level Domain 正向 反向 1H 区域传送 /fin /market . 10Mbps telecom unicom 100G View dnspod www.dns.la web对象缓存 7天 ACL ; A A : NS 子域的实现 授权 TECH market NS SOA: REFRESH RETRY EXPIRE Resolve ARP RARP DNS Hostname ? IP DNS: Hosts IP hostname IANA ftp, hosts DNS 1,2 udp DNS 分布式 DNS服务器的类型： 主DNS服务器 辅助DNS服务器 缓存DNS服务器 转发器 SOA，属性 ARP: cache DNS: cache Client hosts Local DNS cache DNS Server Server Cache Server ? root 资源记录类型 com: org: 子域授权 FQDN: Full Qualified Domain Name com Hostname ? IP: 正向解析 IP ? hostname：反向解析 递归查询 Client ? A ? B ? C 迭代查询 querylog listen-on [ port integer ] { address_match_element; ... }; querylog boolean; version ( quoted_string | none ); allow-recursion { address_match_element; ... }; allow-query { address_match_element; ... }; 子域 The Domain Name System is a distributed database. Allows local control of the segments of the overall database, yet data in each segment is available across the entire network through a client/server scheme. Programs called nameservers constitute the server half of DNSs client/server mechanism. Nameservers contain information about some segments of the database and make that information available to clients, called resolvers . Resolvers are often just library routines that create queries and send them across a network to a nameserver. forward only; If you use forward-only mode, you must have forwarders configured. Forward Zones Traditionally, using forwarders has been an all-or-nothing proposition: either you use forwarders to resolve every query your nameserver cant answer itself, or you dont use forwarders at all. However, there are some situations in which it would be nice to have more control over forwarding. For example, maybe youd like to resolve certain domain names using a particular forwarder but resolve other domain names iteratively. BIND 8.2 introduced a new fe