blob: b7fbb9030eb4dda61f52df61cfb13c2a05040197 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
|
.\" generated with Ronn/v0.7.3
.\" http://github.com/rtomayko/ronn/tree/0.7.3
.
.TH "COREDNS\-SECONDARY" "7" "February 2018" "CoreDNS" "CoreDNS plugins"
.
.SH "NAME"
\fIsecondary\fR \- enables serving a zone retrieved from a primary server\.
.
.SH "DESCRIPTION"
With \fIsecondary\fR you can transfer (via AXFR) a zone from another server\. The retrieved zone is \fInot committed\fR to disk (a violation of the RFC)\. This means restarting CoreDNS will cause it to retrieve all secondary zones\.
.
.IP "" 4
.
.nf
secondary [ZONES\.\.\.]
.
.fi
.
.IP "" 0
.
.IP "\(bu" 4
\fBZONES\fR zones it should be authoritative for\. If empty, the zones from the configuration block are used\. Note that without a remote address to \fIget\fR the zone from, the above is not that useful\.
.
.IP "" 0
.
.P
A working syntax would be:
.
.IP "" 4
.
.nf
secondary [zones\.\.\.] {
transfer from ADDRESS
transfer to ADDRESS
upstream ADDRESS\.\.\.
}
.
.fi
.
.IP "" 0
.
.IP "\(bu" 4
\fBtransfer from\fR specifies from which address to fetch the zone\. It can be specified multiple times; if one does not work, another will be tried\.
.
.IP "\(bu" 4
\fBtransfer to\fR can be enabled to allow this secondary zone to be transferred again\.
.
.IP "\(bu" 4
\fBupstream\fR defines upstream resolvers to be used resolve external names found (think CNAMEs) pointing to external names\. This is only really useful when CoreDNS is configured as a proxy, for normal authoritative serving you don\'t need \fIor\fR want to use this\. \fBADDRESS\fR can be an IP address, and IP:port or a string pointing to a file that is structured as /etc/resolv\.conf\.
.
.IP "" 0
.
.P
When a zone is due to be refreshed (Refresh timer fires) a random jitter of 5 seconds is applied, before fetching\. In the case of retry this will be 2 seconds\. If there are any errors during the transfer the transfer fails; this will be logged\.
.
.SH "EXAMPLES"
Transfer \fBexample\.org\fR from 10\.0\.1\.1, and if that fails try 10\.1\.2\.1\.
.
.IP "" 4
.
.nf
example\.org {
secondary {
transfer from 10\.0\.1\.1
transfer from 10\.1\.2\.1
}
}
.
.fi
.
.IP "" 0
.
.P
Or re\-export the retrieved zone to other secondaries\.
.
.IP "" 4
.
.nf
\&\. {
secondary example\.net {
transfer from 10\.1\.2\.1
transfer to *
}
}
.
.fi
.
.IP "" 0
.
.SH "BUGS"
Only AXFR is supported and the retrieved zone is not committed to disk\.
|
