Forwarders Your DNS may have problems doing name resolution outside the domain it manages. It may defer this work to another DNS which will do the work and return the results back to it. 11.. WWhhyy ddoo tthhiiss?? If your DNS is behind a firewall, it can't reach the _I_n_t_e_r_n_e_t. So it can't fulfill one of its main tasks, which is to provide name resolution. By pointing to a forwarder (often a "caching only" DNS running on the firewall itself), the problem is solved. Another situation for using a forwarder is when a DNS is located at the end of a slow link. Instead of doing name resolution itself, all the queries will be sent to a forwarder at the other end of the link. Often the second DNS has a higher usage than the first, and, thus, already has a greater knowledge. It is in a position to answer the query immediately using its large cache. 22.. TTaasskk Just enter the IP address of the DNS you want to use. The order is important. Put the best first. Put more than one as a backup. 33.. WWhhaatt mmuusstt bbee ddoonnee ttoo aa DDNNSS ssoo tthhaatt iitt aacccceeppttss pprroocceessssiinngg ooff ffoorr-- wwaarrddeedd rreeqquueessttss?? Nothing. 44.. //vvaarr//nnaammeedd//rroooott..ccaacchhee If your DNS is deferring requests to another DNS, the file /var/named/root.cache is not needed! Wrong! This file provides the bootstrap knowledge required to resolve names in other domains. Without this file, your DNS will simply think that nothing else exists except the domains it serves. It won't look further. This is why _L_i_n_u_x_c_o_n_f always try to add it to your DNS configuration!