##### 3.2.2.5.1 Agreed-Upon Change to Website Confirming the Applicant's control over the requested IP Address by confirming the presence of a Request Token or Random Value contained in the content of a file or webpage in the form of a meta tag under the "/.well-known/pki-validation" directory, or another path registered with IANA for the purpose of validating control of IP Addresses, on the IP Address that is accessible by the CA via HTTP/HTTPS over an Authorized Port. The Request Token or Random Value MUST NOT appear in the request. If a Random Value is used, the CA SHALL provide a Random Value unique to the certificate request and SHALL not use the Random Value after the longer of i. 30 days or ii. if the Applicant submitted the certificate request, the time frame permitted for reuse of validated information relevant to the certificate (such as in [Section 4.2.1](#421-performing-identification-and-authentication-functions) of this document).

##### 3.2.2.5.2 Email, Fax, SMS, or Postal Mail to IP Address Contact Confirming the Applicant's control over the IP Address by sending a Random Value via email, fax, SMS, or postal mail and then receiving a confirming response utilizing the Random Value. The Random Value MUST be sent to an email address, fax/SMS number, or postal mail address identified as an IP Address Contact. Each email, fax, SMS, or postal mail MAY confirm control of multiple IP Addresses. The CA MAY send the email, fax, SMS, or postal mail identified under this section to more than one recipient provided that every recipient is identified by the IP Address Registration Authority as representing the IP Address Contact for every IP Address being verified using the email, fax, SMS, or postal mail. The Random Value SHALL be unique in each email, fax, SMS, or postal mail. The CA MAY resend the email, fax, SMS, or postal mail in its entirety, including re-use of the Random Value, provided that the communication's entire contents and recipient(s) remain unchanged. The Random Value SHALL remain valid for use in a confirming response for no more than 30 days from its creation. The CPS MAY specify a shorter validity period for Random Values, in which case the CA MUST follow its CPS.

##### 3.2.2.5.3 Reverse Address Lookup Confirming the Applicant’s control over the IP Address by obtaining a Domain Name associated with the IP Address through a reverse-IP lookup on the IP Address and then verifying control over the FQDN using a method permitted under [Section 3.2.2.4](#3224-validation-of-domain-authorization-or-control).

##### 3.2.2.5.4 Any Other Method Using any other method of confirmation, including variations of the methods defined in [Section 3.2.2.5](#3225-authentication-for-an-ip-address), provided that the CA maintains documented evidence that the method of confirmation establishes that the Applicant has control over the IP Address to at least the same level of assurance as the methods previously described in version 1.6.2 of these Requirements. CAs SHALL NOT perform validations using this method after July 31, 2019. Completed validations using this method SHALL NOT be re-used for certificate issuance after July 31, 2019. Any certificate issued prior to August 1, 2019 containing an IP Address that was validated using any method that was permitted under the prior version of this [Section 3.2.2.5](#3225-authentication-for-an-ip-address) MAY continue to be used without revalidation until such certificate naturally expires.

##### 3.2.2.5.5 Phone Contact with IP Address Contact Confirming the Applicant's control over the IP Address by calling the IP Address Contact’s phone number and obtaining a response confirming the Applicant's request for validation of the IP Address. The CA MUST place the call to a phone number identified by the IP Address Registration Authority as the IP Address Contact. Each phone call SHALL be made to a single number. In the event that someone other than an IP Address Contact is reached, the CA MAY request to be transferred to the IP Address Contact. In the event of reaching voicemail, the CA may leave the Random Value and the IP Address(es) being validated. The Random Value MUST be returned to the CA to approve the request. The Random Value SHALL remain valid for use in a confirming response for no more than 30 days from its creation. The CPS MAY specify a shorter validity period for Random Values.

##### 3.2.2.5.6 ACME “http-01” method for IP Addresses Confirming the Applicant's control over the IP Address by performing the procedure documented for an “http-01” challenge in draft 04 of “ACME IP Identifier Validation Extension,” available at .

##### 3.2.2.5.7 ACME “tls-alpn-01” method for IP Addresses Confirming the Applicant's control over the IP Address by performing the procedure documented for a “tls-alpn-01” challenge in draft 04 of “ACME IP Identifier Validation Extension,” available at .