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                           FREQUENTLY ASKED QUESTIONS

INDEX

     1. I'm still using version 1.0 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.

ANSWERS

1. I'm still using version 1.0 of MaraDNS

   MaraDNS 1.0 will continue to be fully supported until December 21, 2007;
   this means that MaraDNS 1.0 questions will still be answered and bug fixes
   will still be applied. After 2007/12/21, MaraDNS 1.0 will no longer be
   fully supported; the only updates, at that point, would be bugtraq-worthy
   critical security fixes. Not even these security updates will be applied
   after December 21, 2010.

   People who wish to run MaraDNS 1.0 unsupported after 2010/12/21 need to
   keep in mind that MaraDNS 1.0 is not Y2038 compliant, and will have
   problems starting in 2036 or so. MaraDNS 1.2, on the other hand, is fully
   Y2038 compliant.

   There is still a FAQ for version 1.0 of MaraDNS available here.

   Updating from 1.0 to 1.2 requires a minimum number of changes; with most
   configurations, MaraDNS 1.2 is fully compatible with MaraDNS 1.0 data
   files. Details are in the updating document in the tutorial.

   While csv1 zone files are fully supported in MaraDNS 1.2, there is a Perl
   script for updating from CSV1 to CSV2 zone files in the tools/ directory
   of MaraDNS 1.2. 

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 license:
   BSD-type license:

     Copyright (c) 2002-2005 Sam Trenholme

     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?

   Please contact me; my email address is at
   http://www.maradns.org/contact.html 

5. Some of the postings to the mailing list do not talk about MaraDNS!

   In cases where I post something to the mailing list which does not
   directly talk about MaraDNS, the subject line will not have [MARA] in it,
   but will have some form of the word CHATTER in it.

   This way, people who do not like this can set up mail filters to filter
   out anything that comes from this list and doesn't have [MARA] in the
   subject line, or simply unsubscribe from the list and read the list from
   the archives; if one needs to report a bug, they can subscribe to the list
   again, post their bug, then unsubscribe after a week.

   Another option is to set up one's Freshmeat preferences to be notified in
   email every time I update MaraDNS at Freshmeat. This will give one email
   notice of any critical bug fixes without needing to be subscribed to the
   mailing list.

   The web page http://www.maradns.org/ has a link to the mailing list
   archives. 

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, on MaraDNS 1.2.05 and more recent releases, to use a
   special "FQDN4" which automatically sets up the reverse mapping of a given
   record:

     www.example.com. FQDN6 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 MaraDNS can not process recursive queries

   MaraDNS, 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 me know so that I 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?

   The multi-threaded model is, plain and simple, the simplest way to write a
   functioning recursive DNS server. There is a reason why MaraDNS, pdnsd,
   and BIND 9 all use the multi-threaded model. 

13. I feel that XXX feature should be added to MaraDNS

   The only thing that will convince me to implement a given feature for
   MaraDNS is cold, hard cash. If you want me to keep a given feature
   proprietary, you better have lots of cold hard cash. If you're willing to
   opensource your feature, less cash should be sufficient.

   Keep in mind that both the BIND and NSD name servers were developed by
   having the programmers paid to work on the programs. PowerDNS was
   originally commercial software with the author only reluctantly made GPL
   after seeing that the market for a commercial DNS server is very small.
   All of the other DNS servers which have been developed as hobbyist
   projects (Posadis, Pdnsd, and djbdns) are no longer being actively worked
   on by the primary developer.

   I plan on someday adding standards-compliant BIND zone file support. After
   that, I may even add real DNS slave support.

   If I see a large MaraDNS community and a strong demand for new features
   from that community, I will consider their wishes. Especially if some of
   the members of the community have large bank accounts. Should ipv6 start
   to become dominant, I will update MaraDNS to have full ipv6 support.
   Should some other technology come along that will require an update to
   MaraDNS for MaraDNS to continue to function as a DNS server, I may very
   well update MaraDNS to use that technology. 

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-1.2.00/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 me in email, 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 both authoritative and recursive
   UDP 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

   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. 

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 will only compile on FreeBSD, Mac OS X, Cygwin, Linux, and
   partially on MinGW32 systems. If you are interested in porting MaraDNS to
   another system, please let me know. 

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. 

22. MaraDNS freezes up after being used for a while

   If you are using MaraDNS 1.2.03.1 (or any 1.1 release, for that matter) on
   Linux, upgrade to version 1.2.03.2. 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

   The upstream_servers mararc variable is set thusly:

     upstream_servers["."] = "10.3.28.79, 10.2.19.83"

   Note the ["."]. The reason for this is so future versions of MaraDNS may
   have more fine-grained control over the upstream_servers and root_servers
   values.

   Note that the upstream_servers variable needs to be initialized before
   being used via upstream_servers = {} (the reason for this is so that a
   mararc file has 100% Python-compatible syntax). A complete mararc 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 

I have a NS delegation, and MaraDNS is doing strange things.

   In the case of there being a NS delegation, MaraDNS handles recursive
   queries and non-recursive DNS queries differently. Basically, unless you
   use askmara with the -n option, dig with the +norecuse option, or nslookup
   with the -norec option, MaraDNS will try to recursively resolve the record
   that is delegated.

   The thinking is this: A normal recursive DNS query is usually one where
   one wants to know the final DNS output. So, if MaraDNS delegates a given
   record to another DNS server, and gets a recursive request for said query,
   MaraDNS will recursively resolve the query for you.

   For example, let us suppose we have a mararc file that looks like this:

 chroot_dir = "/etc/maradns"
 ipv4_bind_addresses = "10.1.2.3"
 chroot_dir = "/etc/maradns"
 recursive_acl = "127.0.0.1/8, 10.0.0.0/8"
 csv2 = {}
 csv2["example.com."] = "db.example.com"

   And a db.example.com file that looks like this:

 www.example.com.        10.1.2.3
 joe.example.com.        NS ns.joe.example.com.
 ns.joe.example.com.     A 10.1.2.4

   Next, you are trying to find out why www.joe.example.com is not resolving.
   If you naively send a query to 10.1.2.3 for www.joe.example.com as askmara
   Awww.joe.example.com. 10.1.2.3 or as dig @10.1.2.3 www.joe.example.com. or
   as nslookup www.joe.example.com. 10.1.2.3, you will not get any
   information that will help you solve the problem, since 10.1.2.3 will try
   to contact 10.1.2.4 to resolve www.joe.example.com.

   The solution is to run your DNS query client thusly:

     * Askmara would be run thusly:

       askmara -n Awww.joe.example.com. 10.1.2.3

     * Dig would be run thusly:

       dig +norecurse @10.1.2.3 www.joe.example.com

     * Nslookup would be run thusly:

       nslookup -norec www.joe.example.com 10.1.2.3

   This will allow you to see that packets MaraDNS actually sends to a
   recursive DNS server.

   As an aside, this particular problem will not happen if MaraDNS is run
   only as an authoritative nameserver. 

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.