<div dir="ltr"><div>Hello,</div><div><br></div><div>It seems Ultra DNS is responding with NXDOMAIN for "<a href="http://www.uber.com">www.uber.com</a>" queries. Please see the response below:</div><div><br></div><div>Query Link: <a href="https://dnsclient.net/#edns126.ultradns.com/www.uber.com/A/UDP">https://dnsclient.net/#edns126.ultradns.com/www.uber.com/A/UDP</a></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div>
<pre>{
  "Metadata": {
    "NameServer": "<a href="http://edns126.ultradns.com:53">edns126.ultradns.com:53</a> (<a href="http://204.74.66.126:53">204.74.66.126:53</a>)",
    "Protocol": "Udp",
    "DatagramSize": "213 bytes",
    "RoundTripTime": "13.92 ms"
  },
  "Identifier": 21863,
  "IsResponse": true,
  "OPCODE": "StandardQuery",
  "AuthoritativeAnswer": true,
  "Truncation": false,
  "RecursionDesired": true,
  "RecursionAvailable": false,
  "Z": 0,
  "AuthenticData": false,
  "CheckingDisabled": false,
  "RCODE": "NxDomain",
  "QDCOUNT": 1,
  "ANCOUNT": 3,
  "NSCOUNT": 1,
  "ARCOUNT": 0,
  "Question": [
    {
      "Name": "<a href="http://www.uber.com">www.uber.com</a>",
      "Type": "A",
      "Class": "IN"
    }
  ],
  "Answer": [
    {
      "Name": "<a href="http://www.uber.com">www.uber.com</a>",
      "Type": "CNAME",
      "Class": "IN",
      "TTL": "300 (5 mins)",
      "RDLENGTH": "16 bytes",
      "RDATA": {
        "Domain": "<a href="http://frontends-all.uber.com">frontends-all.uber.com</a>"
      }
    },
    {
      "Name": "<a href="http://frontends-all.uber.com">frontends-all.uber.com</a>",
      "Type": "CNAME",
      "Class": "IN",
      "TTL": "300 (5 mins)",
      "RDLENGTH": "18 bytes",
      "RDATA": {
        "Domain": "<a href="http://frontends-cloud.uber.com">frontends-cloud.uber.com</a>"
      }
    },
    {
      "Name": "<a href="http://frontends-cloud.uber.com">frontends-cloud.uber.com</a>",
      "Type": "CNAME",
      "Class": "IN",
      "TTL": "300 (5 mins)",
      "RDLENGTH": "13 bytes",
      "RDATA": {
        "Domain": "<a href="http://cn-ecg.cfe.uber.com">cn-ecg.cfe.uber.com</a>"
      }
    }
  ],
  "Authority": [
    {
      "Name": "<a href="http://uber.com">uber.com</a>",
      "Type": "SOA",
      "Class": "IN",
      "TTL": "900 (15 mins)",
      "RDLENGTH": "58 bytes",
      "RDATA": {
        "PrimaryNameServer": "<a href="http://edns126.ultradns.com">edns126.ultradns.com</a>",
        "ResponsiblePerson": "<a href="http://serviceproviders.uber.com">serviceproviders.uber.com</a>",
        "Serial": 2019057840,
        "Refresh": 3600,
        "Retry": 180,
        "Expire": 604800,
        "Minimum": 900
      }
    }
  ],
  "Additional": []
}</pre>

</div></blockquote><div><br></div><div>However, querying for "<a href="http://cn-ecg.cfe.uber.com">cn-ecg.cfe.uber.com</a>" to the same server responds with an answer:</div><div><br></div><div>Query Link: <a href="https://dnsclient.net/#edns126.ultradns.com/cn-ecg.cfe.uber.com/A/UDP">https://dnsclient.net/#edns126.ultradns.com/cn-ecg.cfe.uber.com/A/UDP</a></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div>
<pre>{
  "Metadata": {
    "NameServer": "<a href="http://edns126.ultradns.com:53">edns126.ultradns.com:53</a> (<a href="http://204.74.66.126:53">204.74.66.126:53</a>)",
    "Protocol": "Udp",
    "DatagramSize": "186 bytes",
    "RoundTripTime": "18.89 ms"
  },
  "Identifier": 9834,
  "IsResponse": true,
  "OPCODE": "StandardQuery",
  "AuthoritativeAnswer": true,
  "Truncation": false,
  "RecursionDesired": true,
  "RecursionAvailable": false,
  "Z": 0,
  "AuthenticData": false,
  "CheckingDisabled": false,
  "RCODE": "NoError",
  "QDCOUNT": 1,
  "ANCOUNT": 1,
  "NSCOUNT": 4,
  "ARCOUNT": 0,
  "Question": [
    {
      "Name": "<a href="http://cn-ecg.cfe.uber.com">cn-ecg.cfe.uber.com</a>",
      "Type": "A",
      "Class": "IN"
    }
  ],
  "Answer": [
    {
      "Name": "<a href="http://cn-ecg.cfe.uber.com">cn-ecg.cfe.uber.com</a>",
      "Type": "A",
      "Class": "IN",
      "TTL": "300 (5 mins)",
      "RDLENGTH": "4 bytes",
      "RDATA": {
        "IPAddress": "34.98.127.226"
      }
    }
  ],
  "Authority": [
    {
      "Name": "<a href="http://cfe.uber.com">cfe.uber.com</a>",
      "Type": "NS",
      "Class": "IN",
      "TTL": "86400 (1 day)",
      "RDLENGTH": "22 bytes",
      "RDATA": {
        "NameServer": "<a href="http://edns126.ultradns.org">edns126.ultradns.org</a>"
      }
    },
    {
      "Name": "<a href="http://cfe.uber.com">cfe.uber.com</a>",
      "Type": "NS",
      "Class": "IN",
      "TTL": "86400 (1 day)",
      "RDLENGTH": "19 bytes",
      "RDATA": {
        "NameServer": "<a href="http://edns126.ultradns.com">edns126.ultradns.com</a>"
      }
    },
    {
      "Name": "<a href="http://cfe.uber.com">cfe.uber.com</a>",
      "Type": "NS",
      "Class": "IN",
      "TTL": "86400 (1 day)",
      "RDLENGTH": "22 bytes",
      "RDATA": {
        "NameServer": "<a href="http://edns126.ultradns.net">edns126.ultradns.net</a>"
      }
    },
    {
      "Name": "<a href="http://cfe.uber.com">cfe.uber.com</a>",
      "Type": "NS",
      "Class": "IN",
      "TTL": "86400 (1 day)",
      "RDLENGTH": "22 bytes",
      "RDATA": {
        "NameServer": "<a href="http://edns126.ultradns.biz">edns126.ultradns.biz</a>"
      }
    }
  ],
  "Additional": []
}</pre>

</div></blockquote><div>Regards,<br></div><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><b>Shreyas Zare</b><br><a href="https://technitium.com" target="_blank">Technitium</a><br></div></div></div></div></div></div></div></div></div></div></div>