sysadmin

Slave/Secondary   DNS Server (Read Only DNS Server) How AXFR & IXFR Works in DNS for Zone Transfer   ? The term slave simply indicates that a name server will obtain the zone records using zone transfer operations but will answer authoritatively for the zone for as long as it has valid zone data (defined by the expiry field of the zone’s SOA RR). The term slave in no sense implies priority of access. As previously described, slave servers will be accessed, in general, just as frequently as any master name server. Slave servers may also transfer their zone files to other slave servers.   The Zone Transfer between Master Server and Secondary Server What is AXFR ? AXFR Transfer : The DNS polling process is accomplished by the slave name server sending a query to the zone master requesting the SOA RR. If the SOA RR’s serial number is greater than the current one maintained by the slave name server, a full zone transfer (AXFR) is requested by ...

How DNS Works ? A DNS domain name is used in a program on the local computer. The request is then passed to the DNS Client service for resolution using locally cached information. If the queried name can be resolved, the query is answered and the process is completed. The local resolver cache can include name information obtained from two possible sources: If a Hosts file is configured locally, any host name-to-address mappings from that file are preloaded into the cache when the DNS Client service is started. For linux /unix the file is # vi /etc/hosts For windows :   c:\Windows\System32\drivers\etc The file is hosts Resource records obtained in answered responses from previous DNS queries are added to the cache and kept for a period of time. If the query does not match an entry in the cache, the resolution process continues with the client querying a DNS server to resolve the name. The cache can be cleared using the comm...