How to resolve the DNS zone in Deadwood?

Sam Trenholme strenholme.usenet at gmail.com
Wed Nov 3 10:25:13 EDT 2010


Thank you for the detailed information.

> filter_rfc1918 = 1

This (which is enabled by default) tells Deadwood to never resolve
private 192.168.x.x, 172.16-31.x.x, and 10.x.x.x IP addresses (which
are described in RFC1918, hence the name).  This is a security
feature; if we allow a DNS server used on the real-world Internet to
resolve these kinds of IPs, it opens us up to certain kinds of
attacks:

http://crypto.stanford.edu/dns/

If you have a need to resolve these kinds of IPs, please have filter_rfc1918 = 0

> ;; AUTHORITY SECTION:
> my.tv.                 0       IN      SOA     z.my.tv. y.my.tv. 1 1 1 1 1

Whenever Deadwood generates a reply it looks like this, it indicates
that Deadwood is generating a synthetic "this host does not exist"
reply.

This can be done under a variety of circumstances.  For example:

* If reject_aaaa is set and someone asks for an AAAA (IPv6 address) record

* If Deadwood gets a response from an upstream server which is blank
and the RCODE isn't SERVER FAIL

* If an IP specified in ip_blacklist is seen in the upstream reply
(this feature exists to counteract NXDOMAIN redirection)

* If, as happened in your case, a 192.168.x.x, 172.16-32.x.x, or
10.x.x.x IP is seen in the reply and filter_rfc1918 is not 0.

> Proposition:
> Cached NS (Deadwood) together with Authoritative server (MaraDNS) = new version of GOOD NS named DeadDNS
> (from DEADwood+maraDNS=DeadDNS) ;)

Thank you for the kind words.

- Sam


More information about the list mailing list