Add a man page section on parallel queries.
[haeredes.git] / doc / man1 / haeredes.1
1 .TH haeredes 1
2
3 .SH NAME
4 haeredes \- Confirm delegation of NS and MX records.
5 .SH SYNOPSIS
6
7 \fBhaeredes\fR [\fIOPTIONS\fR] [\fIDELEGATES\fR]
8 .SH INPUT
9 .P
10 A list of domains, separated by whitespace.
11 .SH OUTPUT
12 .P
13 A list of domains which don't have the supplied (expected) delegates
14 listed as their NS/MX records.
15 .SH DESCRIPTION
16 .P
17 Haeredes is primarily useful for ISP network administrators. Customers
18 will occasionally decide to switch hosts without alerting the current
19 host; this can cause two problems.
20 .P
21 With NS records, the previous host (at the very least) keeps hosting a
22 DNS zone that does nothing. If that host uses their authoritative
23 nameserver as a caching lookup server as well, it may return
24 incorrect results to queries about the domain in question.
25 .P
26 For MX records, the situation is slightly worse. Most mail servers
27 will immediately accept mail for which the server thinks it is the
28 ultimate destination. If a mail server is configured as the
29 destination for a domain, but it is not the MX for that domain, then
30 mail submitted to that server may possibly be lost. It is therefore
31 important to remove domains from the old mail host as soon as the MX
32 record is changed.
33 .P
34 Haeredes can alert administrators when NS/MX records are changed.
35 .SH NORMALIZATION
36 .P
37 By default, domain/hostnames given will be normalized in two ways:
38 .IP \[bu] 2
39 All names will be lowercased.
40
41 .IP \[bu]
42 All names will have a trailing dot (the DNS root) appended if one is
43 not present. This can be controlled with the
44 \fB\-\-no\-append\-root\fR flag.
45 .SH QUERY RESULTS
46 .P
47 When Haeredes makes a query for an MX record, the result is parsed
48 from the \(dqanswer\(dq section of the response. This is
49 straightforward.
50 .P
51 For NS records, however, there are two sections that may contain
52 results. If you query the authoritative nameservers for example.com,
53 they will return the response in the \(dqanswer\(dq section, as with
54 MX records:
55
56 .nf
57 .I $ dig +short @a.iana-servers.net example.com NS
58 b.iana-servers.net.
59 a.iana-servers.net.
60 .fi
61 .P
62 However, if you ask a root server, they will return the response in
63 another section, called \(dqauthority\(dq. The \(dqanswer\(dq section
64 is empty:
65
66 .nf
67 .I $ dig +short @a.gtld-servers.net example.com NS
68 .fi
69 .P
70 We have to request the \(dqauthority\(dq section explicitly:
71
72 .nf
73 .I $ dig +noall +authority @a.gtld-servers.net example.com NS
74 example.com. 172800 IN NS a.iana-servers.net.
75 example.com. 172800 IN NS b.iana-servers.net.
76 .fi
77 .P
78 Given Haeredes' use case, it is useful to combine the two. You can
79 query a root server to check the registrar data, or a recursive
80 resolver to check the data on the authoritative nameservers.
81 .P
82 So that's what we do. In NS mode, Haeredes will check both the
83 \(dqanswer\(dq and \(dqauthority\(dq sections for results.
84 .SH PARALLEL QUERIES
85 .P
86 Haeredes can use multiple threads to perform its queries. It will use
87 a number of threads equal to the number of processors available to the
88 GHC runtime. This can be changed with the \fI+RTS \-N\fR flag. For
89 example, to use 10 threads,
90
91 .nf
92 $ haeredes [OPTIONS] [DELEGATES] \fI+RTS -N10\fR
93 .fi
94 .SH OPTIONS
95
96 .IP \fB\-\-no\-append\-root\fR,\ \fB-n\fR
97 Don't append a trailing dot to any DNS names. If you know what you're
98 doing, this can be used to check relative results. Otherwise, it will
99 probably just lead to false positives.
100 .IP \fB\-\-server\fR,\ \fB-s\fR
101 Use the given DNS server rather than the resolvers listed in
102 /etc/resolv.conf. Either an IP address or a hostname will work.
103 .SH EXAMPLES
104
105 .IP \[bu] 2
106 Make sure example.com has the expected name servers,
107 [ab].iana-servers.net:
108
109 .nf
110 .I $ haeredes a.iana-servers.net b.iana-servers.net <<< \(dqexample.com\(dq
111 .fi
112
113 .IP \[bu] 2
114 If you use \-\-no\-append\-root and your nameservers are rooted, you
115 must remember to supply the trailing dot yourself. Otherwise, you'll
116 get false positives.
117
118 .nf
119 .I $ haeredes \-\-no\-append\-root \\\\
120 .I " a.iana-servers.net b.iana-servers.net" \\\\
121 .I " <<< \(dqexample.com\(dq"
122 Domain \(dqexample.com\(dq delegates somewhere else:
123 \(dqb.iana-servers.net.\(dq \(dqa.iana-servers.net.\(dq
124 .fi
125 .IP \[bu]
126 Check orlitzky.com against the expected name servers, using
127 a root nameserver (this checks the registrar configuration):
128
129 .nf
130 .I $ haeredes --server d.gtld-servers.net dns1.viabit.com dns2.viabit.com \\\\
131 .I " <<< \(dqorlitzky.com\(dq"
132 .fi
133 .IP \[bu]
134 Check orlitzky.com against only one of the expected two nameservers:
135
136 .nf
137 .I $ haeredes dns1.viabit.com <<< \(dqorlitzky.com\(dq
138 Domain \(dqorlitzky.com.\(dq delegates somewhere else: \
139 \(dqdns2.viabit.com.\(dq
140 .fi
141 .IP \[bu]
142 Check a nonexistent domain (we provide no delegates, since we
143 know .invalid will not be delegated):
144
145 .nf
146 .I $ haeredes <<< \(dqexample.invalid\(dq
147 Domain \(dqexample.invalid.\(dq not delegated.
148 .fi
149 .SH BUGS
150 .P
151 Send bugs to michael@orlitzky.com.