Configuring rDNS Lookups for Enterprise Agents

A reverse DNS lookup or resolution (rDNS) queries the Domain Name System (DNS) to determine the domain name associated with an IP address. This is the opposite of a standard DNS lookup, which determines the IP address associated with a domain name.

ThousandEyes Enterprise Agents perform rDNS lookups for RFC 1918 addresses by default. The agent performs lookups for each hop in the path, until it encounters a non-RFC 1918 address, or one that is not in the configured rDNS ranges.

This article provides the steps to extend rDNS lookups by the agent for public IP addresses.

Prerequisites

• One or more ThousandEyes Enterprise Agents or clusters.

Configuration

To configure the agent's reverse DNS behavior:

1. In the ThousandEyes web app:

   • For Enterprise Agents, navigate to Cloud and Enterprise Agents > Agent Settings > Enterprise Agents > Agents.

   • For clusters, navigate to Cloud and Enterprise Agents > Agent Settings > Enterprise Agents > Clusters.

2. Click the Enterprise Agent or cluster you wish to configure to open the Edit Configuration panel.

3. Open the Advanced Settings tab.

4. In the Reverse DNS section, add the public IP ranges that should be used for the rDNS lookups.

1. After adding the ranges, click Save Changes.

To configure multiple Enterprise Agents at once:

1. Navigate to Cloud and Enterprise Agents > Agent Settings > Enterprise Agents > Agents.

2. Select the checkbox beside each desired Enterprise Agent, or the checkbox beside Agent Name to select all.

3. From the bottom configuration options panel, open the Edit menu and select Edit Reverse DNS.

1. In the Reverse DNS side panel, configure the public IP ranges, and click Save Changes.

Once configured, the domain name for each hop will be displayed in the Path Visualization. Hover the cursor over the node to see that node's details: