Publisher review:pdnsd is a proxy DNS server with permanent caching. pdnsd is a proxy DNS server with permanent caching (the cache contents are written to hard disk on exit) that is designed to cope with unreachable or down DNS servers (for example in dial-in networking).Since version 1.1.0, pdnsd supports negative caching.It is licensed under the GNU General Public License (GPL, also available in html and translated into various languages). This, in short, means that the sources are distributed togehter with the program, and that you are free to modify the sources and redistribute them as long as you also license them under the GPL. You do not need to pay anything for pdnsd. It also means that there is ABSOLUTELY NO WARRANTY for pdnsd or any part of it. For details, please read the GPL.
pdnsd can be used with applications that do DNS lookups, e.g. on startup, and can't be configured to change that behaviour, to prevent the often minute-long hangs (or even crashes) that result from stalled DNS queries. Some Netscape Navigator versions for Unix, for example, expose this behaviour.
pdnsd is configurable via a file and supports run-time configuration using the program pdnsd-ctl that comes with pdnsd. This allows you to set the status flags of servers that pdnsd knows (to influence which servers pdnsd will query), and the addition, deletion and invalidation of DNS records in pdnsd's cache. Parallel name server queries are supported. This is a technique that allows querying several servers at the same time so that very slow or unavailable servers will not block the answer for one timeout interval. Since version 1.0.0, pdnsd has full IPv6 support.
There is also a limited support for local zone records, intended for defining 1.0.0.127.in-addr.arpa. and localhost. , since some clients request that information and it must be served even if the cached servers are not available or do not serve these records. pdnsd may also read your /etc/hosts file (this file is normally used by your local resolver and usually contains information for localhost as well as for your machines FQDN) and serve its contents.
pdnsd was started on Linux, and has since been ported to FreeBSD (and Cygwin and Darwin). 90% of the source code should be easily portable to POSIX- and BSD-compatible systems, provided that those systems support the POSIX threads (pthreads). The rest might need OS-specific rewrites.
Currently, pdnsd is only compileable by gcc. This should be easy to fix, but I just do not have documentation for other compilers. If you are not able or do not want to use gcc, I would recommend you just try to do the minor changes.
pdnsd must be started as root in some cases (raw sockets are needed for icmp echoes for the option uptest=ping, and the default port is 53, this must be >1024 to allow non-root execution). However, pdnsd can be configured to change it's user and group id to those of a non-privileged user after opening the sockets needed for this.
The server should support the full standard DNS queries following the rfcs 1034 and 1035. As of version 1.0.0, the rfc compliance has been improved again, and pdnsd is now believed (or hoped?) to be fully rfc-compatible. It completely follows rfc 2181 (except for one minor issue in the FreeBSD port). It does not support the following features, of which most are marked optional, experimental or obsolete in these rfcs:
- Inverse queries
- Status queries
- Completion queries
- Namespaces other than IN (Internet)
- AXFR and IXFR queries (whole zone transfers); since pdnsd does not maintain zones, that should not violate the standard
The following record types, that are extensions to the original DNS standard, are supported for caching at a compile time option (if you do not need them, you do not need to compile support for them into pdnsd and save cache and executable space):
- RP (responsible person, RFC 1183)
- AFSDB (AFS database location, RFC 1183)
- X25 (X25 address, RFC 1183)
- ISDN (ISDN number/address, RFC 1183)
- RT (route through, RFC 1183)
- NSAP (Network Service Access Protocol address , RFC 1348)
- PX (X.400/RFC822 mapping information, RFC 1995)
- GPOS (geographic position, deprecated)
- AAAA (IPv6 address, RFC 1886)
- LOC (location, RFC 1876)
- EID (Nimrod EID)
- NIMLOC (Nimrod locator)
- SRV (service record, RFC 2052)
- ATMA (ATM address)
- NAPTR (URI mapping, RFC 2168)
- KX (key exchange, RFC 2230)
There are FreeBSD and OpenBSD ports available for pdnsd (ports/net/pdnsd for both). Thanks go to Roman Shterenzon for the FreeBSD port Sebastian Stark for the OpenBSD one! Thanks to Kiyo Kelvin Lee now also runs on the Cygwin platform! Thanks goes to Rodney Brown for extending portability to the Darwin (Apple Mac OS X) platform! Requirements: · Kernel version >2.2.0 · glibc version >2.0.1 (aka libc6) with LinuxThreads (normally included) or NPTL (Native Posix Thread Library, recommended). · For IPv6: glibc>=2.1
pdnsd 1.2.5 is a C/C++ script for PHP Classes scripts design by Paul Rombouts.
It runs on following operating system: Windows / Linux / Mac OS / BSD / Solaris.
pdnsd is a proxy DNS server with permanent caching.
Operating system:Windows / Linux / Mac OS / BSD / Solaris
pdnsd 1.2.5 script details 
