If you would like to use Okta with a dynamic IP-Addr you need to update the IP manually or use this tiny script to do this by cronjob.

OktaUpdateIpZone.sh

#!/bin/bash
api_token=<INSERT YOUR API KEY>

curl --silent -X PUT \
-H "Accept: application/json" \
-H "Content-Type: application/json" \
-H "Authorization: SSWS ${api_token}" \
-d '{
  "type": "IP",
  "id": "<ZONE-ID>",
  "name": "<INSERT NAME>",
  "status": "ACTIVE",
  "created": "2017-01-24T19:53:28.000Z",
  "lastUpdated": "2017-01-24T19:53:28.000Z",
  "system": false,
  "gateways": [
    {
      "type": "CIDR",
      "value": "'"$(curl --silent ipecho.net/plain)"'/24"
    }
  ],
  "proxies": [],
  "_links": {
    "self": {
      "href": "https://<OKTA-ORG>.okta.com/api/v1/zones/<ZONE-ID>",
      "hints": {
        "allow": [
          "GET",
          "PUT",
          "DELETE"
        ]
      }
    },
    "deactivate": {
      "href": "https://<OKTA-ORG>.okta.com/api/v1/zones/<ZONE-ID>/lifecycle/deactivate",
      "hints": {
        "allow": [
          "POST"
        ]
      }
    }
  }
}' "https://<OKTA-ORG>.okta.com/api/v1/zones/<ZONE-ID>" > /dev/null