# Regex with "interval" flag enabled to filter private-ip-addresses

**URL:** <https://discuss.elastic.co/t/regex-with-interval-flag-enabled-to-filter-private-ip-addresses/280826>\
**Category:** Kibana\
**Created:** [August 9, 2021, 3:37pm UTC](https://discuss.elastic.co/t/regex-with-interval-flag-enabled-to-filter-private-ip-addresses/280826 "2021-08-09T15:37:21Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![jnair](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/jnair/32/92709_2.png) [@jnair](https://discuss.elastic.co/u/jnair)\
**Post date:** [August 9, 2021, 3:37pm UTC](https://discuss.elastic.co/t/regex-with-interval-flag-enabled-to-filter-private-ip-addresses/280826/1 "2021-08-09T15:37:21Z")

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In the kibana visualization query interface, in the "Add filter -\> Edit as Query DSL" editor, I am using the below "REGEX" filter queries with the **"INTERVAL"** flag set, to filter the Private-IP addresses. I did check the search output and seems to works. The use of the INTERVAL facility seems to be more clean and readable. Note I do know there exits the CIDR notation, but since my "ipa" field is set to type "keyword" I guess I will not be able to use the CIDR notation until the administrator changes the field to type "ip" and re-indexes the data, till then I plan to use the below technique. Is there any shortcomings in using this INTERVAL facility?

```auto
// filter1 (10.0.0.0 – 10.255.255.255)
{
  "query": {
    "regexp": {
      "ipa": {
        "value": "10[.]<0-255>[.]<0-255>[.]<0-255>",
        "flags": "INTERVAL"
      }
    }
  }
}

// filter2 (172.16.0.0 – 172.31.255.255)
{
  "query": {
    "regexp": {
      "ipa": {
        "value": "172[.]<16-31>[.]<0-255>[.]<0-255>",
        "flags": "INTERVAL"
      }
    }
  }
}

// filter3 (192.168.0.0 – 192.168.255.255)
{
  "query": {
    "regexp": {
      "ipa": {
        "value": "192[.]168[.]<0-255>[.]<0-255>",
        "flags": "INTERVAL"
      }
    }
  }
}

// filter4 (169.254.1.0 - 169.254.254.255) (link-local) 
{
  "query": {
    "regexp": {
      "ipa": {
        "value": "169[.]254[.]<1-254>[.]<0-255>",
        "flags": "INTERVAL"
      }
    }
  }
}

```

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [September 6, 2021, 3:37pm UTC](https://discuss.elastic.co/t/regex-with-interval-flag-enabled-to-filter-private-ip-addresses/280826/2 "2021-09-06T15:37:25Z")

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