FREQUENTLY ASKED QUESTIONS
INDEX
1. I'm using an older version of MaraDNS
2. How do I try out MaraDNS?
3. What license is MaraDNS released under?
4. How do I report bugs in MaraDNS?
5. Some of the postings to the mailing list do not talk
about MaraDNS!
6. How do I get off the mailing list?
7. How do I set up reverse DNS on MaraDNS?
8. I am on a slow network, and MaraDNS can not process
recursive queries
9. When I try to run MaraDNS, I get a
cryptic error message.
10. After I start MaraDNS, I can not see the process
when I run netstat -na
11. What string library does MaraDNS use?
12. Why does MaraDNS use a multi-threaded model?
13. I feel that XXX feature should be added to MaraDNS
14. I feel that MaraDNS should use another documentation
format
15. Is there any process I need to follow to add a patch
to MaraDNS?
16. Can MaraDNS act as a primary nameserver?
17. Can MaraDNS act as a secondary nameserver?
18. What is the difference between an authoritative and
a recursive DNS server?
19. The getzone client isn't allowing me to add certain
hostnames to my zone
20. Is MaraDNS portable?
21. Can I use MaraDNS in Windows?
22. MaraDNS freezes up after being used for a while
23. What kind of Python integration does MaraDNS have
24. Doesn't "kvar" mean "four" in Esperanto?
25. How scalable is MaraDNS?
26. I am having problems setting
upstream_servers
27. Why doesn't the MaraDNS.org web page validate?
28. How do MX records work?
29. Does MaraDNS have support for SPF?
30. I'm having problems resolving CNAMES I have set up.
31. I have a NS delegation, and MaraDNS is doing
strange things.
32. I am transferring a zone from another
server, but the NS records are these strange "synth-ip" records.
33. Where is the root.hints file?
34. Are there any plans to use autoconf to build
MaraDNS?
35. How do I change the compiler or compile-time flags
with MaraDNS' build process?
36. Will you make a package for the particular Linux
distribution I am using?
37. I am using the native Windows port of MaraDNS,
and some features are not working.
38. MaraDNS isn't starting up
39. You make a lot of releases of MaraDNS; at our
ISP/IT department, updating software is non-trivial.
40. I have star records in my zones, and am having
problems with NXDOMAINs/IPV6 resolution
41. I have a zone with only SOA/NS records, and the
zone is not working.
42. I am having problems registering my domain with AFNIC
(the registrar for .fr domains)
43. I can't see the full answers for subdomains I have
delegated
44. MaraDNS 1 has a problem resolving a domain
45. MaraDNS 1.2 has issues with NXDOMAINS and
case sensitivity.
46. Can MaraDNS offer protection from phishing and
malicious sites?
47. Does maradns support star (wildcard) records?
48. I'm having problems using MaraDNS with some *NIX
command line applications like telnet
49. My virus scanner reports that MaraDNS or Deadwood
has a virus
50. I can not subscribe to the MaraDNS mailing
list
51. How does MaraDNS respond to EDNS (RFC2671) packets?
52. How to I get MaraDNS to always give the same IP to
all DNS queries?
ANSWERS
1. I'm using an older version of MaraDNS
Upgrade to MaraDNS 1.4 or MaraDNS 2.0. MaraDNS 1.4 is compatible with
older versions of MaraDNS, with the relatively few changes need to upgrade
documented.
Use MaraDNS 2.0 if there are any issues using MaraDNS 1.4 to recursively
resolve records (via recursive_acl); the recursive resolver
in MaraDNS 1.4 is deprecated and only critical security issues are fixed
with it. MaraDNS 2.0 uses the separate daemon Deadwood to recursively
resolve records.
MaraDNS 1.0 and 1.2 are only supported for critical security updates, and
will no longer be supported on December 21, 2010. MaraDNS 1.3 is also only
supported for critical security updates, and support will stop on December
21, 2012. MaraDNS 1.4 and MaraDNS 2.0 are both fully supported (security
and other important bug fixes) for the foreseeable future.
2. How do I try out MaraDNS?
Read the quick
start guide, which is the file named 0QuickStart in the MaraDNS
distribution.
3. What license is MaraDNS released under?
MaraDNS 1.2 is released with the following two-clause
BSD-type license:
Copyright (c) 2002-2009 Sam Trenholme and others
TERMS
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
This software is provided 'as is' with no guarantees of correctness or
fitness for purpose.
4. How do I report bugs in MaraDNS?
Send an email to the MaraDNS mailing list. Details on how to do
this are at
http://www.maradns.org/
5. Some of the postings to the mailing list do not talk about MaraDNS!
Topic drift sometimes happens. It's a part of life.
6. How do I get off the mailing list?
Send an email to list-request@maradns.org with "unsubscribe" as the
subject line.
7. How do I set up reverse DNS on MaraDNS?
Reverse DNS (sometimes called "reverse mapping") is set up by using
PTR (pointer) records. For example, the PTR record which performs
the reverse DNS lookup for the ip 10.2.3.4 looks like this in a CSV2 zone
file:
4.3.2.10.in-addr.arpa. PTR www.example.com.
It is also possible to use a special "FQDN4" which automatically sets up
the reverse mapping of a given record:
www.example.com. FQDN4 10.2.3.4
If you wish to have a PTR (reverse DNS lookup; getting a DNS name from a
numeric IP) record work on the internet at large, it is not a simple
matter of just adding a record like this to a MaraDNS zonefile. One also
needs control of the appropriate in-addr.arpa. domain.
While it can make logical sense to contact the IP 10.11.12.13 when trying
to get the reverse DNS lookup (fully qualified domain name) for a given
IP, DNS servers don't do this. DNS server, instead, contact the root
DNS servers for a given in-addr.arpa name to get the reverse DNS lookup,
just like they do with any other record type.
When an internet service provider is given a block of IPs, they are also
given control of the DNS zones which allow them to control reverse DNS
lookups for those IPs. While it is possible to obtain a domain and run
a DNS server without the knowledge or intervention of an ISP, being
able to control reverse DNS lookups for those IPs requires ISP
intervention.
8. I am on a slow network, and Deadwood can not process recursive
queries
Deadwood, by default, only waits two seconds for a reply from a remote
DNS server. This default can be increased by adding a line like this
in the mararc file:
timeout_seconds = 5
Note that making this too high will slow MaraDNS down when DNS servers
are down, which is, alas, all too common on today's internet.
9. When I try to run MaraDNS, I get a cryptic
error message.
There is usually some context of where there is a syntax error in a
data file before the cryptic error message. For example, when there
is a syntax error in a csv2 zone file, MaraDNS will tell you exactly
at what point it had to terminate parsing of the zone file.
If MaraDNS does return a cryptic error message without letting you know
what is wrong, let us know on the mailing list
so that we can fix the bug. MaraDNS is designed
to be easy to use; cryptic error messages go against this spirit.
10. After I start MaraDNS, I can not see the process when I run netstat -na
Udp services do not have a prominent "LISTEN" when netstat is run.
When MaraDNS is up, the relevant line in the netstat output looks
like this:
udp 0 0 127.0.0.1:53 0.0.0.0:*
While on the topic of netstat, if you run netstat -nap as root
on Linux and some other *nix operating systems, you can see the names of
the processes which are providing internet services.
11. What string library does MaraDNS use?
MaraDNS uses its own string library, which is called the "js_string"
library. Man pages for most of the functions in the js_string library
are in the folder doc/man of the MaraDNS
distribution
12. Why does MaraDNS use a multi-threaded model?
MaraDNS 2.0 no longer uses threads.
The multi-threaded model was the simplest way to write
a functioning recursive DNS server for MaraDNS 1.0. There is a reason
why MaraDNS, pdnsd, and BIND 9 all use the multi-threaded model.
It took me nearly three years to rewrite MaraDNS' recursive resolver
as a separate non-threaded daemon. This has been done, and now all recursion
is done with Deadwood which does not need threads.
13. I feel that XXX feature should be added to MaraDNS
There are no plans to add new features to MaraDNS or Deadwood at
this time.
14. I feel that MaraDNS should use another documentation format
The reason that MaraDNS uses its own documentation format is to satisfy both
the needs of translators to have a unified document format and my own
need to use a documentation format that is simple enough to be readily
understood and which I can add features on an
as needed basis.
The documentation format is essentially simplified HTML with some
special tags added to meet MaraDNS' special needs.
This gives me more flexibility to adapt the documentation format to
changing needs. For example, when someone pointed out that it's not
a good idea to have man pages with hi-bit characters, it was a simple matter
to add a new HIBIT tag which allows man pages to be without
hi-bit characters, and other document formats to retain hi-bit characters.
Having a given program have its own documentation format is not
without precedent; Perl uses its own "pod" documentation format.
15. Is there any process I need to follow to add a patch to MaraDNS?
Yes.
Here is the procedure for making a proper patch:
- Enter the directory that the file is in, for example
maradns-1.4.01/server
- Copy over the file that you wish to modify to another file
name. For example: cp MaraDNS.c MaraDNS.c.orig
- Edit the file in question, e.g: vi MaraDNS.c
- After editing, do something like this:
diff -u MaraDNS.c.orig MaraDNS.c > maradns.patch
- Make sure the modified version compiles cleanly
Send a patch to the MaraDNS mailing list, along with a statement that you place
the contents of the patch under MaraDNS' BSD license. If I find that the patch
works well, I will integrate it in to MaraDNS.
16. Can MaraDNS act as a primary nameserver?
Yes.
The zoneserver program serves zones so that other DNS servers
can be secondaries for zones which MaraDNS serves. This is a separate
program from the maradns server, which processes
authoritative UDP DNS queries, and Deadwood which processes recursive
DNS queries.
See the DNS
master document in the MaraDNS tutorial for details.
17. Can MaraDNS act as a secondary nameserver?
Yes.
Please read the
DNS slave document, which is part of the MaraDNS tutorial.
18. What is the difference between an authoritative and a recursive DNS
server?
A recursive DNS server is a DNS server that is able to contact other DNS
servers in order to resolve a given domain name label. This is the kind
of DNS server one points to in
/etc/resolve.conf. MaraDNS uses
the Deadwood daemon to process recursive DNS queries.
An authoritative DNS server is a DNS server that a recursive server
contacts in order to find out the answer to a given DNS query. The
maradns daemon processes authoritative DNS queries.
19. The fetchzone client isn't allowing me to add certain hostnames to
my zone
For security reasons, MaraDNS' fetchzone client does not
add records which are not part of the zone in question. For example,
if someone has a zone for example.com, and this record in the zone:
1.1.1.10.in-addr.arpa. PTR dns.example.com.
MaraDNS will not add the record, since the record is out-of-bailiwick. In
other words, it is a host name that does not end in .example.com.
There are two workarounds for this issue:
- Create a zone file for 1.1.10.in-addr.arpa., and put the PTR records
there.
- Use rcp, rsync, or another method to copy over the zone files in
question.
20. Is MaraDNS portable?
MaraDNS is developed on a CentOS 5 and Windows XP dual boot laptop.
MaraDNS may or may not compile and run on other systems.
21. Can I use MaraDNS in Windows?
Yes. There is both a partial mingw32 (native win32 binary) port and a full
Cygwin port of MaraDNS; both of these ports are part of the native build
of MaraDNS. Deadwood has full Windows support, including the ability to
run as a service.
22. MaraDNS freezes up after being used for a while
There is a bug with the Linux kernel
which causes UDP clients to freeze unless code is written to work around
the kernel bug. This workaround was first introduced in MaraDNS 1.0.28
and 1.1.35 and accidently disabled in 1.2.03.1.
If using your ISP's name servers or some other name servers which
are not, in fact, root name servers, please make sure that you are
using the upstream_servers dictionary variable instead of the
root_servers dictionary variable.
If you still see MaraDNS freeze up after making this correction, please
send a bug report to the mailing list.
23. What kind of Python integration does MaraDNS have
The mararc file uses the same syntax that Python uses; in fact, Python
can parse a properly formatted mararc file.
There is currently no other integration with Python.
24. Doesn't "kvar" mean "four" in Esperanto?
Indeed, it does. However the use of "kvar" in the MaraDNS source
code only coincidentally is an Esperanto word. "kvar" is short
for "Kiwi variable"; a lot of the parsing code comes from the code
used in the Kiwi spam filter project.
25. How scalable is MaraDNS?
MaraDNS is optimized for serving a small number of domains as quickly
as possible. That said, MaraDNS is remarkably efficnent for serving a
large number of domains, as long as the server MaraDNS is on has the
memory to fit all of the domains, and as long as the startup time for
loading a large number of domains can be worked around.
The "big-O" or "theta" growth rates for various MaraDNS functions
are as follows, where N is the number of authoritative host names being
served:
Startup time N
Memory usage N
Processing incoming DNS requests 1
As can be seen, MaraDNS will process 1 or 100000 domains in the same amount
of time, once the domain names are loaded in to memory.
26. I am having problems setting upstream_servers
upstream_servers is only supported by Deadwood, and is no
longer supported in MaraDNS 2.0.
The
upstream_servers dwood3rc variable is set thusly:
upstream_servers["."] = "10.3.28.79, 10.2.19.83"
Note the
["."].
Note that the upstream_servers variable needs to be initialized
before being used via upstream_servers = {} (the reason for this
is so that a dwood3rc file has 100% Python-compatible syntax). A complete
dwood3rc file that uses upstream_servers may look like this:
ipv4_bind_addresses = "127.0.0.1"
chroot_dir = "/etc/maradns"
recursive_acl = "127.0.0.1/8"
upstream_servers = {}
upstream_servers["."] = "10.1.2.3, 10.2.4.6"
27. Why doesn't the MaraDNS.org web page validate?
HTML pages on the MaraDNS.org web site should validate as
HTML 4.0 Transitional. However, the CSS will not validate.
I have designed MaraDNS' web page to be usable and as attractive as possible
in any major browser released in the last ten years. Cross-browser support
is more important than strict W3
validation. The reason why the CSS does not validate is because
I need a way to make sure there is always a scrollbar on the web page,
even if the content is not big enough to merit one; this is to avoid the
content jumping from page to page. There is no standard
CSS tag that lets me do this. I'm using a non-standard tag to enable
this in Gecko (Firefox's rendering engine); this is enabled by default in
Trident (Internet Explorer's rendering engine). The standards are deficient
and blind adherence to them would result in an inferior web site.
There are also two validation warnings generated by redefinitions which
are needed as part of the CSS filters used to make the site attractive on
older browsers with limited CSS support.
On a related note, the reason why I use tables instead of CSS for some of
the layout is because Microsoft Internet Explorer 6 and other browsers do
not have support for the max-width CSS property. Without this
property, the web page will not scale down correctly without using tables.
Additionally, tables allow a reasonably attractive header in browsers
without CSS support.
28. How do MX records work?
How MX records work:
- The mail transport agent (Sendmail, Postfix, Qmail, MS Exchange, etc.)
looks up the MX record for the domain
- For each of the records returned, the MTA (mail transport agent) looks
up the IP for the names.
- It will choose, at random, any of the MXes with the lowest priority number.
- Should that server fail, it will try another server with the same
priority number.
- Should all MX records with a given priority number fail, the MTA will
try sending email to any of the MX records with the second-lowest
priority value.
As an aside, do not have MX records point to CNAMEs.
29. Does MaraDNS have support for SPF?
SPF, or sender policy framework, is method of using DNS that makes
it more difficult to forge email. MaraDNS has full support for SPF,
both via TXT records and, starting with MaraDNS 1.2.08, via RFC4408
SPF records.
SPF configuration is beyond the scope of MaraDNS' documentation. However,
at the time of this FAQ entry being written (June, 2006), information
and documentation concerning SPF is available at
http://openspf.org. The BIND examples
will work in MaraDNS csv2 zone files as long as the double quotes (") are
replaced by single quotes ('). For example, a SPF TXT record that
looks like example.net. IN TXT "v=spf1 +mx a:colo.example.com/28 -all"
in a BIND zone file will look like
example.net. TXT 'v=spf1 +mx a:colo.example.com/28 -all' in a
MaraDNS zone file. MaraDNS version 1.2.08 and higher can also make
the corresponding SPF record, which will have the syntax
example.net. SPF 'v=spf1 +mx a:colo.example.com/28 -all'.
30. I'm having problems resolving CNAMES I have set up.
This is probably because you have set up what MaraDNS calls a dangling CNAME
record.
Let us suppose we have a CNAME record without an A record in the local
DNS server's database, such as:
google.example.com. CNAME www.google.com.
This record, which is a CNAME record for "google.example.com", points
to "www.google.com". Some DNS servers will recursively look up
www.google.com, and render the above record like this:
google.example.com. CNAME www.google.com.
www.google.com. CNAME 66.102.7.104
For security reasons, MaraDNS doesn't do this. Instead, MaraDNS will simply
output:
google.example.com. CNAME www.google.com.
Some stub resolvers will be unable to resolve google.example.com as
a consequence.
If you set up MaraDNS to resolve CNAMEs thusly, you will get a warning
in your logs about having a dangling CNAME record.
If you want to remove these warnings, add the following to your mararc file:
no_cname_warnings = 1
Information about how to get MaraDNS to resolve dangling CNAME
records is in the tutorial file dangling.html
31. I have a NS delegation, and MaraDNS is doing
strange things.
This is only an issue in MaraDNS 1.4. MaraDNS 2.0 does not allow
the same IP to both authoritatively and recursively resolve records.
32. I am transferring a zone from another
server, but the NS records are these strange "synth-ip" records.
MaraDNS expects, in csv2 zone files, for all
delegation NS records to be between the SOA record and the first
non-NS record.
If a zone looks like this:
example.net. +600 soa ns1.example.net.
hostmaster@example.net 10 10800 3600 604800 1080
example.net. +600 mx 10 mail.example.net.
example.net. +600 a 10.2.3.5
example.net. +600 ns ns1.example.net.
example.net. +600 ns ns3.example.net.
mail.example.net. +600 a 10.2.3.7
www.example.net. +600 a 10.2.3.11
Then the NS records will be "synth-ip" records.
The zone should look like this:
example.net. +600 soa ns1.example.net.
hostmaster@example.net 10 10800 3600 604800 1080
example.net. +600 ns ns1.example.net.
example.net. +600 ns ns3.example.net.
example.net. +600 mx 10 mail.example.net.
example.net. +600 a 10.2.3.5
mail.example.net. +600 a 10.2.3.7
www.example.net. +600 a 10.2.3.11
This will remove the "synth-ip" records.
To automate this process, this awk script is useful:
fetchzone whatever.zone.foo 10.1.2.3 | awk '
{if($3 ~ /ns/ || $3 ~ /soa/){print}
else{a = a "\n" $0}}
END{print a}' > zonefile.csv2
Replace "whatever.zone.foo" with the name of the zone you are
fetchin 10.1.2.3 with the IP address of the DNS master, and
zonefile.csv2 with the name of the zone file MaraDNS loads.
33. Where is the root.hints file?
MaraDNS (actually, Deadwood), unlike BIND, does not need a complicated
root.hints file in order to have custom root servers. In order to change
the root.hints file, add something like this to your dwood3rc file:
root_servers["."] = "131.161.247.232,"
root_servers["."] += "208.185.249.250,"
root_servers["."] += "66.227.42.140,"
root_servers["."] += "66.227.42.149,"
root_servers["."] += "65.243.92.254"
Note that there is no "+=" in the first line, and the last line does not
have a comma at the end. Read the recursive tutorial document for more
information.
34. Are there any plans to use autoconf to build
MaraDNS?
No.
In more detail, MaraDNS does not use autoconf for the following reasons:
- Autoconf is designed to solve a problem that existed in the mid 1990s
but does not exist today: A large number of different incompatible C
compilers and libc implementations. These days, most systems are using
gcc as the compiler and some version of glibc as the libc. There is
no longer a need, for example, to figure out whether a given
implementation of getopt() allows '--' options.
MaraDNS's ./configure script can be run in only a second or
two; compare this to the 3-5 minute process autoconf's ./configure
needs.
- Autoconf leaves GPL-tained files in a program's build tree. MaraDNS is
licensed under a BSD license that is not GPL-compatible, so
MaraDNS can not be distributed with these GPL-licensed files.
This leads us to the next question:
35. How do I change the compiler or compile-time flags
with MaraDNS' build process?
To change the compiler used by MaraDNS:
- Run the ./configure script
- Open up the file Makefile with an editor
- Look for a line that starts with CC
- If there is no line that starts with CC, create one just before
the line that starts with FLAGS
- Change (or create) that line to look something like CC=gcc296
In this example, the 2.96 version of gcc is used to compile MaraDNS.
- Note that it is important to not remove anything from this line
you do not understand; doing so will make MaraDNS unable to compile
or run. So, if the CC line looks like
CC=gcc $(LDFLAGS) -DNO_FLOCK and you want to compile
with gcc 2.96, change the line to look like
CC=gcc296 $(LDFLAGS) -DNO_FLOCK retaining the flags
added by the configuration script.
Changing compile-time flags is a similar process:
- Run the ./configure script
- Open up the file Makefile with an editor
- Look for a line that starts with FLAGS
- Change (or create) that line to look something like FLAGS=-O3
In this example, MaraDNS is compiled with the -O3 option.
- Note that it is important to not remove anything from this line
you do not understand; doing so will make MaraDNS unable to compile
or run. So, if the FLAGS line looks like
FLAGS=-O2 -Wall -DSELECT_PROBLEM and you want to compile
at optimization level three, change this line to look like
FLAGS=-O2 -Wall -DSELECT_PROBLEM retaining the flags
added by the configuration script. -DSELECT_PROBLEM for example,
is needed in the Linux compile or MaraDNS will have problems with
freezing up.
36. Will you make a package for the particular Linux
distribution I am using?
No.
There is, however, a CentOS 5-compatible RPM spec file in the build directory.
37. I am using the native Windows port of MaraDNS,
and some features are not working.
Since Windows 32 does not have some features that *NIX OSes have, the native
Windows port does not have all of the features of the *NIX version of
MaraDNS. In particular, the following features are disabled:
- ipv6 (this is actually a mingw32, not a Windows deficiency)
- The chroot_dir mararc variable
- The maradns_gid and maradns_uid mararc variables
- The maxprocs mararc variable
- The synth_soa_serial variable can not have a value of 2
If any of the above features are desired, try compiling MaraDNS using
Cygwin. Note that the Cygwin port of MaraDNS does not have ipv6 support,
and that while
chroot_dir works in Cygwin, it does not have
the security that the *NIX chroot() call has.
38. MaraDNS isn't starting up
This is usually caused by a syntax error in one's mararc file, or by
another MaraDNS process already running. To see what is happening, look
at your system log (
/var/log/messages in Centos 3) to see what
errors MaraDNS reports. If you do not know how to look at a system
log, you can also invoke MaraDNS from the command line as root; any errors
will be visible when starting MaraDNS.
39. You make a lot of releases of MaraDNS; at our
ISP/IT department, updating software is non-trivial.
The number of releases seen in the
changelog
is not an accurate reflection of how often someone using a stable
branch of MaraDNS will need to update.
MaraDNS 1.2 and 1.3.07, the older stable branches of MaraDNS, were last
updated in August of 2008.
I go to a great deal of effort to make sure MaraDNS releases are as
painless to update as possible. I ensure configuration file format
compatibility, even between major versions of MaraDNS. With the exception
of configuration file parser bugfixes, MaraDNS 1.0 configuration files
are compatible with MaraDNS 1.4.
It is impossible to make code that is bug-free or without security
problems. This is especially true with code that runs on the public
internet.1 Code has to be updated from
time to time. What I do in order to minimize the disruption caused by an
update is to always have a stable bugfix-only branch of MaraDNS (right now I
have two bugfix-only branches), and to, as much as possible, evenly
space out the bugfix updates.
Footnote 1: Even DJB's code has security problems. Both Qmail and DjbDNS
have known security problems, and need to be patched before put on a public
internet server.
40. I have star records in my zones, and am having problems with
NXDOMAINs/IPV6 resolution
This was a bug in MaraDNS 1.2 which has long since been fixed.
41. I have a zone with only SOA/NS records, and the zone is not
working.
MaraDNS 1.2 has a bug where it does not correctly process zones without
any "normal" records. For example, suppose a zone like this:
% SOA localhost. root@localhost. 1 7200 600 1209600 3600
% NS localhost.
This zone will not work until some non-SOA/NS record is added, such
as in this zone file:
% SOA localhost. root@localhost. 1 7200 600 1209600 3600
% NS localhost.
foo.% TXT 'MaraDNS 1.2 needs this record.'
This bug has been fixed in MaraDNS 1.3 and 1.4; since this is not a
security bug (there is a perfectly good workaround), this bug will not
be fixed in MaraDNS 1.2 unless you pay me to fix it.
42. I am having problems registering my domain with AFNIC (the registrar
for .fr domains)
Because of an issue with AFNIC (who, annoyingly enough, check the RA bit
when registering a domain), in order to register a domain with AFNIC using
MaraDNS as your DNS server, the following steps need to be followed:
- MaraDNS version 1.4 or 2.0 needs to be used; if you're using an
older version of MaraDNS, upgrade.
- It is necessary to have recursion disabled, if using MaraDNS 1.4, either
by compiling MaraDNS without recursive support (./configure --authonly ; make),
or by making sure MaraDNS does not have recursion enabled (by not having
recursive_acl set in one's MaraDNS 1.4 mararc file)
If one wishes to both register domains with AFNIC and use MaraDNS 1.4 as a
recursive DNS server, it is required to have the recursive server be a
separate instance of MaraDNS on a separate IP. It is not possible to have
the same DNS server both send DNS packets in a way that both makes AFNIC
happy and allows recursive queries.
Note also: AFNIC gives warnings about reverse DNS lookups; more
information about this issue can be found in the FAQ entry
about reverse DNS mappings (question 7). In addition, AFNIC
requires DNS-over-TCP to work; information on configuring MaraDNS to
have this can be found in the DNS-over-TCP
tutorial.
43. I can't see the full answers for subdomains I have delegated
To have the subdomains be visible to MaraDNS 1.4 recursive nameservers,
add the following to your mararc file:
recurse_delegation = 1
44. MaraDNS 1 has a problem resolving a domain
This issue should be fixed in MaraDNS 2.0.
Here's what happening: I have rewritten the recursive resolver for MaraDNS.
The old code was always designed to be a placeholder until I wrote a new
recursive resolver.
The new recursive resolver is called "Deadwood"; right now it's fully
functional and part of MaraDNS 2.0. More information is here:
http://maradns.blogspot.com/search/label/Deadwood
http://maradns.org/deadwood/
Since the old recursive code is a bit difficult to maintain, and since I
in the process of rewriting the recursive code, my rule is that I will only
resolve security issues with MaraDNS 1.0's recursive resolver.
45. MaraDNS 1.2 has issues with NXDOMAINS and case sensitivity.
There is a known bug in MaraDNS 1.2.12 where, should a client ask for
a non-existent record in all caps, MaraDNS 1.2.12 will return a NXDOMAIN
instead of a "not there" reply. This can cause there to be problems
delivering email to the host in question if a mail transport agent asks
for a name in all caps.
If this is an issue for your organization, please upgrade to a newer
version of MaraDNS; MaraDNS 1.4 and 2.0 do not have
this bug. If you want to see this bug fixed in MaraDNS 1.2, please
help sponsor MaraDNS.
46. Can MaraDNS offer protection from phishing and
malicious sites?
Yes.
Here is a webpage that explains how its done:
http://www.malwaredomains.com/?p=288
Should that website be down, I have made a local mirror of the
Perl script here:
createmaradns-pl.txt
47. Does maradns support star (wildcard) records?
Yes.
MaraDNS supports both having stars at the beginning of records and the
end of records. For example, to have anything.example.com. have
the IP 10.1.2.3, add this line to the zone file for example.com:
*.example.com. A 10.1.2.3
To have stars at the end of records, csv2_default_zonefile has to
be set. The mararc parameter bind_star_handling affects how
star records are handled. More information is in the mararc man page.
48. I'm having problems using MaraDNS with some *NIX
command line applications like telnet.
Some *NIX command line networking applications, such as telnet and ssh,
try to do either a reverse DNS lookup (IP-to-host name conversion) or an
IPv6 lookup. This slows things down and sometimes causes the applications
to not work at all.
For people who do not need IPv6 lookups, add the following line to
one's mararc file to have MaraDNS respond to all IPv6 lookups with a
bogus "not found" reply:
reject_aaaa = 1
If knowing the hostname a given IP has isn't important, these kinds of lookups
can also be disabled:
reject_ptr = 1
49. My virus scanner reports that MaraDNS or Deadwood
has a virus
This can be caused either by a poorly written anti-virus program reporting
a false positive, or because a virus on your system has infected your copy
of MaraDNS/Deadwood.
Please use GPG to verify that the
file which your scanner reports having a virus in has not been altered.
In addition, please scan the file with AVG (free for non-commercial use)
to verify your virus scanner has not reported a false positive.
If you have verified the GPG signature of the program and AVG reports a
virus, please let us know on the MaraDNS mailing list. Otherwise, please
use a better virus scanner and make sure there are no viruses on your
computer.
50. I can not subscribe to the MaraDNS mailing list
The procedure for subscribing to the mailing list is as follows:
- Send an email to list-request@maradns.org with "Subscribe" as the subject
- You will get an email from list-request@maradns.org asking you to
confirm your subscription. This can be done by replying to the
message, or, more simply, by clicking on the link in the message.
- Once you click on that link, click on the button marked
"subscribe to list list"
- You will now get a message stating 'Welcome to the "list" mailing list'.
- This email will tell you how to post to the mailing list. I suggest
reading it.
If you get an email from list-request@maradns.org with the subject
"The results of your email commands", you did not correctly send an
email to list-request@maradns.org with the subject "Subscribe".
If you do not get the email from list-request@maradns.org asking you for
a confirmation, ensure that this email is not in your "spam" or "junk
mail" folder. If you are unable to get these emails at your email address,
please get a gmail email account, which can successfully subscribe to the
MaraDNS mailing list.
51. How does MaraDNS respond to EDNS (RFC2671) packets?
MaraDNS 1.4 responds to EDNS packets by ignoring the OPT record and acting
as if it the packet did not have an OPT record.
Deadwood (the recursive resolver
for Deadwood 2.0, available in the deadwood-#.#.## directory of any 1.4
MaraDNS release), up through Deadwood
2.9.02 responds to EDNS packets by discarding the packet and not
responding. This was changed in Deadwood 2.9.03: Deadwood, as
per RFC2671 section 5.3, now responds to EDNS queries by replying with
the NOTIMPL ("not implemented") error code instead of answering the query.
This was changed again in Deadwood 2.9.04: Deadwood now, like MaraDNS 1
(as well as DJBdns), handles a EDNS packet as if the OPT record did not
exist.
MicroDNS (available
in the tools/misc directory of any 1.4 MaraDNS release), as of
MaraDNS 1.4.05, responds to EDNS queries the same way Deadwood 2.9.03 did:
By giving back "NOTIMPL" instead of answering the query with the
default IP. NanoDNS, in the
interest of minimizing code side, responds to EDNS requests by returning
NOTIMPL in the header, giving the OPT query in the AN section of the
response, and giving the default IP in the AR section of the DNS
reply packet.
52. How to I get MaraDNS to always give the same IP to all DNS
queries?
There are three ways to have MaraDNS always give the same IP in reply
to any DNS query given to it:
- The best way to do this is to set up a default zonefile
that causes any and all A queries to always give the IP (and also allows
all AAAA queries to always give out the same IP6, all SPF or TXT queries
to give out the same SPF record, etc.).
- Another possibility, if someone just wants a simple DNS server that
always gives out the same IP address to any and all DNS queries, is
to use the MicroDNS program, available in tools/misc, as well
as having its own
web page.
- If MicroDNS is too bloated, there is also NanoDNS, which
I will include the source code of below:
/*Placed in the public domain by Sam Trenholme*/
#include <arpa/inet.h>
#include <string.h>
#include <stdint.h>
#define Z struct sockaddr
#define Y sizeof(d)
int main(int a,char **b){uint32_t i;char q[512]
,p[17]="\xc0\f\0\x01\0\x01\0\0\0\0\0\x04";if(a>
1){struct sockaddr_in d;socklen_t f=511;bzero(&
d,Y);a=socket(AF_INET,SOCK_DGRAM,0);*((uint32_t
*)(p+12))=inet_addr(b[1]);d.sin_family=AF_INET;
d.sin_port=htons(53);bind(a,(Z*)&d,Y);for(;;){i
=recvfrom(a,q,255,0,(Z*)&d,&f);if(i>9&&q[2]>=0)
{q[2]|=128;q[11]?q[3]|=4:1;q[7]++;memcpy(q+i,p,
16);sendto(a,q,i+16,0,(Z*)&d,Y);}}}return 0;}
NanoDNS takes one argument: The IP we return. This program binds to all
IP addresses a given machine has on the UDP DNS port (port 53). For example,
to make a DNS server that binds to all IPs your system has and return the
IP 10.11.12.13 to any UDP DNS queries sent to it, compile the above C program,
call it
NanoDNS, and invoke it with
NanoDNS 10.11.12.13
Note that NanoDNS does not daemonize, nor log anything, nor have any other
space-wasting features.