Domain control validation backoff schedule
Domain control validation (DCV) has to happen before a Certificate Authority (CA) will issue a certificate for a domain.
DCV happens with Cloudflare’s CA partners according to the following schedule:
- Digicert - 30 days
- Google Trust Services - 14 days
- Let’s Encrypt - 7 days
Afterward, DCV tokens expire as dictated by the CA/B Baseline Requirements, which govern issuance of publicly trusted SSL certificates.
Here is the function that is used to determine the next check:
now() + min((floor(60 * pow(1.05, retry_attempt)) * INTERVAL '1 second'), INTERVAL '4 hours')
As the table below shows, most of the checks take place on the first day. Most validations complete within the first 5 minutes, unless the customer has misconfigured the CNAME to your domain. We cap the check back off to a maximum of 4 hours to avoid the function growing exponentially, which would result in large gaps between checks towards the end of the month.
Retry Attempt | In Seconds | In Minutes | In Hours |
---|---|---|---|
0 | 60 | 1.000 | 0.016667 |
1 | 63 | 1.050 | 0.017500 |
2 | 66 | 1.100 | 0.018333 |
3 | 69 | 1.150 | 0.019167 |
4 | 72 | 1.200 | 0.020000 |
5 | 76 | 1.267 | 0.021111 |
6 | 80 | 1.333 | 0.022222 |
7 | 84 | 1.400 | 0.023333 |
8 | 88 | 1.467 | 0.024444 |
9 | 93 | 1.550 | 0.025833 |
10 | 242 | 4.033 | 0.067222 |
11 | 279 | 4.650 | 0.077500 |
12 | 321 | 5.350 | 0.089167 |
13 | 369 | 6.150 | 0.102500 |
14 | 424 | 7.067 | 0.117778 |
15 | 488 | 8.133 | 0.135556 |
16 | 561 | 9.350 | 0.155833 |
17 | 645 | 10.750 | 0.179167 |
18 | 742 | 12.367 | 0.206111 |
19 | 853 | 14.217 | 0.236944 |
20 | 981 | 16.350 | 0.272500 |
21 | 1129 | 18.817 | 0.313611 |
22 | 1298 | 21.633 | 0.360556 |
23 | 1493 | 24.883 | 0.414722 |
24 | 1717 | 28.617 | 0.476944 |
25 | 1975 | 32.917 | 0.548611 |
26 | 2271 | 37.850 | 0.630833 |
27 | 2612 | 43.533 | 0.725556 |
28 | 3003 | 50.050 | 0.834167 |
29 | 3454 | 57.567 | 0.959444 |
30 | 3972 | 66.200 | 1.103333 |
31 | 4568 | 76.133 | 1.268889 |
32 | 5253 | 87.550 | 1.459167 |
33 | 6041 | 100.683 | 1.678056 |
34 | 6948 | 115.800 | 1.930000 |
35 | 7990 | 133.167 | 2.219444 |
36 | 9189 | 153.150 | 2.552500 |
37 | 10567 | 176.117 | 2.935278 |
38 | 12152 | 202.533 | 3.375556 |
39 | 13975 | 232.917 | 3.881944 |
40 | 14400 | 240.000 | 4.000000 |
41 | 14400 | 240.000 | 4.000000 |
42 | 14400 | 240.000 | 4.000000 |
43 | 14400 | 240.000 | 4.000000 |
44 | 14400 | 240.000 | 4.000000 |
45 | 14400 | 240.000 | 4.000000 |
46 | 14400 | 240.000 | 4.000000 |
47 | 14400 | 240.000 | 4.000000 |
48 | 14400 | 240.000 | 4.000000 |
49 | 14400 | 240.000 | 4.000000 |
50 | 14400 | 240.000 | 4.000000 |
51 | 14400 | 240.000 | 4.000000 |
52 | 14400 | 240.000 | 4.000000 |
53 | 14400 | 240.000 | 4.000000 |
54 | 14400 | 240.000 | 4.000000 |
55 | 14400 | 240.000 | 4.000000 |
56 | 14400 | 240.000 | 4.000000 |
57 | 14400 | 240.000 | 4.000000 |
58 | 14400 | 240.000 | 4.000000 |
59 | 14400 | 240.000 | 4.000000 |
60 | 14400 | 240.000 | 4.000000 |
61 | 14400 | 240.000 | 4.000000 |
62 | 14400 | 240.000 | 4.000000 |
63 | 14400 | 240.000 | 4.000000 |
64 | 14400 | 240.000 | 4.000000 |
65 | 14400 | 240.000 | 4.000000 |
66 | 14400 | 240.000 | 4.000000 |
67 | 14400 | 240.000 | 4.000000 |
68 | 14400 | 240.000 | 4.000000 |
69 | 14400 | 240.000 | 4.000000 |
70 | 14400 | 240.000 | 4.000000 |
71 | 14400 | 240.000 | 4.000000 |
72 | 14400 | 240.000 | 4.000000 |
73 | 14400 | 240.000 | 4.000000 |
74 | 14400 | 240.000 | 4.000000 |
75 | 14400 | 240.000 | 4.000000 |
76 | 14400 | 240.000 | 4.000000 |
77 | 14400 | 240.000 | 4.000000 |
78 | 14400 | 240.000 | 4.000000 |
79 | 14400 | 240.000 | 4.000000 |
80 | 14400 | 240.000 | 4.000000 |
81 | 14400 | 240.000 | 4.000000 |
82 | 14400 | 240.000 | 4.000000 |
83 | 14400 | 240.000 | 4.000000 |
84 | 14400 | 240.000 | 4.000000 |
85 | 14400 | 240.000 | 4.000000 |
86 | 14400 | 240.000 | 4.000000 |
87 | 14400 | 240.000 | 4.000000 |
88 | 14400 | 240.000 | 4.000000 |
89 | 14400 | 240.000 | 4.000000 |
90 | 14400 | 240.000 | 4.000000 |
91 | 14400 | 240.000 | 4.000000 |
92 | 14400 | 240.000 | 4.000000 |
93 | 14400 | 240.000 | 4.000000 |
94 | 14400 | 240.000 | 4.000000 |
95 | 14400 | 240.000 | 4.000000 |
96 | 14400 | 240.000 | 4.000000 |
97 | 14400 | 240.000 | 4.000000 |
98 | 14400 | 240.000 | 4.000000 |
99 | 14400 | 240.000 | 4.000000 |
100 | 14400 | 240.000 | 4.000000 |
101 | 14400 | 240.000 | 4.000000 |
102 | 14400 | 240.000 | 4.000000 |
103 | 14400 | 240.000 | 4.000000 |
104 | 14400 | 240.000 | 4.000000 |
105 | 14400 | 240.000 | 4.000000 |
106 | 14400 | 240.000 | 4.000000 |
107 | 14400 | 240.000 | 4.000000 |
108 | 14400 | 240.000 | 4.000000 |
109 | 14400 | 240.000 | 4.000000 |
110 | 14400 | 240.000 | 4.000000 |
111 | 14400 | 240.000 | 4.000000 |
112 | 14400 | 240.000 | 4.000000 |
113 | 14400 | 240.000 | 4.000000 |
114 | 14400 | 240.000 | 4.000000 |
115 | 14400 | 240.000 | 4.000000 |
116 | 14400 | 240.000 | 4.000000 |
117 | 14400 | 240.000 | 4.000000 |
118 | 14400 | 240.000 | 4.000000 |
119 | 14400 | 240.000 | 4.000000 |