--- title: "RFC2136" date: 2019-03-03T16:39:46+01:00 draft: false slug: rfc2136 --- Configuration for [RFC2136](https://tools.ietf.org/html/rfc2136). - Code: `rfc2136` {{% notice note %}} _Please contribute by adding a CLI example._ {{% /notice %}} ## Credentials | Environment Variable Name | Description | |-----------------------|-------------| | `RFC2136_NAMESERVER` | Network address in the form "host" or "host:port" | | `RFC2136_TSIG_ALGORITHM` | TSIG algorythm. See [miekg/dns#tsig.go](https://github.com/miekg/dns/blob/master/tsig.go) for supported values. To disable TSIG authentication, leave the `RFC2136_TSIG*` variables unset. | | `RFC2136_TSIG_KEY` | Name of the secret key as defined in DNS server configuration. To disable TSIG authentication, leave the `RFC2136_TSIG*` variables unset. | | `RFC2136_TSIG_SECRET` | Secret key payload. To disable TSIG authentication, leave the` RFC2136_TSIG*` variables unset. | The environment variable names can be suffixed by `_FILE` to reference a file instead of a value. More information [here](/lego/dns/#configuration-and-credentials). ## Additional Configuration | Environment Variable Name | Description | |--------------------------------|-------------| | `RFC2136_DNS_TIMEOUT` | API request timeout | | `RFC2136_POLLING_INTERVAL` | Time between DNS propagation check | | `RFC2136_PROPAGATION_TIMEOUT` | Maximum waiting time for DNS propagation | | `RFC2136_SEQUENCE_INTERVAL` | Interval between iteration | | `RFC2136_TTL` | The TTL of the TXT record used for the DNS challenge | The environment variable names can be suffixed by `_FILE` to reference a file instead of a value. More information [here](/lego/dns/#configuration-and-credentials). ## More information - [API documentation](https://tools.ietf.org/html/rfc2136)