Luke Scharf wrote: > I've run into this problem before: how do I empty the DNS cache in > Linux? > I remember doing this with 'ndc', reading about it for 'rndc'... though it appears this function isn't well documented, or supported in older versions of BIND. root# man rndc -points to "The BIND 9 Administrator Reference Manual" Chapter 3. Name Server Configuration - Tools for Use With the Name Server Daemon - rndc http://www.isc.org/sw/bind/arm93/Bv9ARM.ch03.html#id2547661 root# rndc dumpdb -cache localhost # appears to work on FC4 root# rpm -qa | grep -i bind bind-9.3.1-14_FC4 There have been so many changes to BIND, it really requires an up2date book & lots of 'dig'in... Flushing (Clearing) a Name Server's Cache http://www.oreillynet.com/pub/a/network/excerpt/dnsbindcook_ch05/?page=2#flushing root# rndc flush internal rndc: 'flush' failed: failure # apparently I'm not configured for multiple 'views' root# rndc flushname localhost.localdomain # seems to work & is a better option than restarting the dns server RHEL4 RefGuide: Berkeley Internet Name Domain (BIND) - Using rndc (good start, but little help) http://www.redhat.com/docs/manuals/enterprise/RHEL-4-Manual/ref-guide/s1-bind-rndc.html Quick HOWTO: Configuring DNS - Migrating Your Web Site In-House (very good) http://www.siliconvalleyccie.com/linux-hn/dns-static.htm#_Toc92808691 From my collection of bookmarks on configuing BIND, there are some rather nice DNS howto's here & most distros ship with a caching nameserver preconfigured... The Name Service HOWTO http://www.cryptnet.net/fdp/admin/nameservice.html DNS Oversimplified: How to check your DNS http://www.rscott.org/dns/ Configuring Bind - Linux StepByStep http://www.linux-sxs.org/internet_serving/dns.html DNS and DHCP at Arda.Homeunix.Net http://www.arda.homeunix.net/dnssetup.html O'Reilly DNS and BIND, Fourth Edition http://www.oreilly.com/catalog/dns4/ DNS HOWTO - rather dated http://www.tldp.org/HOWTO/DNS-HOWTO.html DNSRD - DNS Resources Directory http://www.dns.net/dnsrd/ DNSSEC: DNS Security Extensions http://www.dnssec.net/ DNS Server Hardening http://www.linux-sec.net/DNS/ That is likely more than you ever wanted to know, but hopefully provides some useful references to others maintaining DNS. -HTH Art@JAX
