# cfxdm - dm:dns\_ip\_to\_name

**dm:dns\_ip\_to\_name:** It allows to resolve the IP addresses listed in a column to FQDN names into another column.

**dm:dns\_ip\_to\_name:** Syntax

* **from\_cols** (mandatory)**:** Comma separated list of column names which has IP Address values
* **to\_cols** (mandatory)**:** Comma separated list of column names to store resolved DNS Names (FQDN).
* **keep\_value** (optional): If it is set to **'yes',** it stores the original value, else it stores 'null' value. By default it is set to '**no**'
* **num\_threads** (optional): Number of DNS lookup threads. Must be in the range of 1 to 20, Default is set to 5.

{% hint style="info" %}
This tag uses the DNS servers configured on the host os where **cfxdx** is installed and running for IP Address to DNS or FQDN name resolution.
{% endhint %}

{% hint style="info" %}
It requires an input dataset or a tag which has one or more columns with IP Address values.
{% endhint %}

In the below example, tag [**dm:recall**](https://docs.cloudfabrix.io/rda/rda-userguide/rda-data-management-cfxdm/cfxdx-dm-recall) is used to retrieve the data from an existing saved dataset.

```
tag @dm:recall
```

```
data name = 'netstat-app-connections' --> @dm:dns_ip_to_name from_cols = 'localAddr' & to_cols = 'localAddr_fqdn' & keep_value = 'yes'
```

As shown in the below screen, dataset '**netstat-app-connections**' has a column called '**localAddr**' with IP Address values in it which is ingested into **dm:dm:dns\_ip\_to\_name** tag to enrich the IP Address values by resolving them into fully qualified domain names and store the output into a new column called '**localAddr\_fqdn**'. 

**keep\_value = 'yes'** : This means, if an IP Address is not resolved to DNS name (FQDN), it will maintain the same IP Address as a value instead of leaving it as empty.

![](https://2978683539-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LhoMVYxiQlKXh6OxX98%2F-MXFRMUY0UuD94JzXIJZ%2F-MXFV8e_PkdpLkp0LkjH%2FScreen%20Shot%202021-04-01%20at%207.53.52%20PM.png?alt=media\&token=ea376e35-aa58-4866-9aac-c57749096c50)

Below screen output shows the resolved DNS name (FQDN) under column '**localAddr\_fqdn**'

![](https://2978683539-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LhoMVYxiQlKXh6OxX98%2F-MXFRMUY0UuD94JzXIJZ%2F-MXFVVT-01TEdd1VOeBf%2FScreen%20Shot%202021-04-01%20at%207.55.33%20PM.png?alt=media\&token=6f516d19-16ff-417a-b08d-233acb2efed9)