Deadwood FAQ

What is Deadwood?

   Deadwood is the recursive DNS daemon (service) for the up and
   coming MaraDNS 2.0. MaraDNS 2.0 is going to have separate
   programs for authoritative records (maradns) and recursive
   records (Deadwood). Deadwood is a standalone recursive server
   that can either be used in conjunction with MaraDNS, or by
   itself. The program can run either in CentOS 5 (and hopefully
   other Linux and *NIX flavors) or in Windows XP (as well as newer
   Windows releases).

   The reason for this rewrite is because I have never been
   satisfied with the recursive resolver in MaraDNS 1.0. When I
   designed MaraDNS 1.0's recursive resolver, there were a number
   of things needed to get full recursion to work that I did not
   anticipate. By the time I shoehorned in all of the features
   needed in a fully recursive DNS server, the code was rather
   messy and difficult to maintain.

   Ever since 2002, my plan has been to rewrite MaraDNS' recursive
   code. In the fall of 2007, I finally started making the code;
   the code became feature complete in the summer of 2010.

How do I use Deadwood?

   Create a configuration file, /etc/dwood3rc, that looks like
   this:

 bind_address="127.0.0.1"
 recursive_acl="127.0.0.1/8"
 chroot_dir="/etc/deadwood"

   Now, create an empty directory owned by root called
   /etc/deadwood. Once this is done, compile Deadwood (as per
   INSTALL.txt), and see if it runs. The above configuration file
   will only allow connections using the loopback interface on the
   same machine to resolve domains with Deadwood.

How do I convert a MaraDNS mararc file in to a Deadwood dwood3rc file?

   While some effort has been made to have Deadwood use the same
   syntax and variables as MaraDNS, there are some differences to
   keep in mind:

     * Deadwood does not have a "ipv4_alias" parameter.
     * Deadwood handles "verbose_level" differently; to get fully
       verbose messages, "verbose_level" has to be 100 (as opposed
       to MaraDNS' 10)

I changed a configuration parameter but it has not affected Deadwood

   Be sure to delete the cache file when making any changes to
   Deadwood's configuration. In Windows, the cache file is called
   dw_cache_bin (unless the dwood3rc.txt file is edited); in
   CentOS, with the default dwood3rc file, the file is called
   dw_cache.

Deadwood sends out a lot of queries

   Deadwood will do this on a slow network, since the default
   parameters are tuned to get a fast reply on a broadband internet
   connection. On a slow (dialup, saturated broadband, etc)
   connection, timeout_seconds should have a value of 7 and
   num_retries should have a value of 1. This is done by adding the
   following lines to the dwood3rc file:

 timeout_seconds = 7
 num_retries = 1

Steve Gibson's DNS benchmark reports that Deadwood is dropping a lot
of DNS packets

   After running this tool and carefully looking at Deadwood's
   replies to Gibson's DNS benchmark tool, I can safely conclude
   that Gibson's tool is buggy and that Deadwood is not dropping
   the packets being sent to it.

   A much better tool to use is Namebench, which correctly shows
   that Deadwood drops very few (if any) DNS packets sent to it.
   Namebench is available at available at
   http://code.google.com/p/namebench/

Can Deadwood blacklist by domain?

   Yes.

   To blacklist a domain, add a line like this to the dwood3rc
   file:

 upstream_servers["example.com."] = "192.168.255.255"

   Replace "example.com." with the domain to be blacklisted, and
   replace "192.168.255.255" with an IP that is either:

     * Guaranteed to be unreachable from the server running
       Deadwood. In this case, any attempt to reach a blacklisted
       domain will result in Deadwood timing out and eventually
       returning a "SERVER FAIL" error message.
     * Running a DNS server that always returns the same IP to a
       given DNS query. This can be set up by using
       "csv2_default_zonefile" in MaraDNS, running "microdns"
       (included in MaraDNS' source tree), or even by running
       "nanodns".

   Deadwood uses a hash to store these blacklisted domains, and
   should be able to store thousands of such domains without
   significant slowdown.

   If it is more convenient to store the domains in separate files,
   this can be done using Deadwood's "execfile" mechanism.

Does Deadwood have DNSSEC support?

   No. I have nothing against DNSSEC per se, but I plain simply am
   not in a position to take the time and effort to implement
   DNSSEC without being compensated for my work.