---
sourceDocument: Yokohama IT Operations Management
sourceDocumentLink: https://servicenow-prod.fluidtopics.net/r/yokohama/it-operations-management

 Release :

    - yokohama

ft:locale :

    - en-US

ft:publication_title :

    - Yokohama IT Operations Management

ft:clusterId :

    - itom

bundleId :

    - itom

workflow :

    - Technology


---

# DNS probe

# DNS probe {#ariaid-title1}

* Release version: Yokohama
* 
* Updated January 30, 2025
* 
* ![](https://www.servicenow.com/docs/portal-asset/ico-clock) 1 minute to read

DNS probes determine the DNS names for configuration items (CI).
The default DNS Name Resolver probe is a lightweight and fast probe. It achieves its speed
by executing in parallel on the MID Server. The probe utilizes DNS lookup by the MID Server
host OS to make use of the maintained DNS cache. The probe also leverages the hosts file on
the OS.

These performance improvements can be disabled by reverting to the legacy DNS probe with
either MID Server properties or parameters. The names of the MID Server
properties/parameters are \[mid.probe.use_legacy_forward_dns\] and
\[mid.probe.use_legacy_reverse_dns\]. For more information, see [MID Server parameters](https://www.servicenow.com/docs/access?context=mid-server-parameters&version=yokohama&pubname=yokohama-servicenow-platform&ft:locale=en-US) and [MID Server properties](https://www.servicenow.com/docs/access?context=r_MIDServerProperties&version=yokohama&pubname=yokohama-servicenow-platform&ft:locale=en-US).
{#dns-discovery-probe__table_n1d_zfw_33b__entry__2}

| Probe | Description |
|-|-|
| DNS | Determines DNS names for devices. It has the parameter ip_addresses. |
| DNSLookupProbe | Resolves the IP address of a host. |
| DNSNameResolver | Resolves the DNS name of an IP address. |
[Table 1. DNS probe definitions]

{#dns-discovery-probe__table_n1d_zfw_33b} {#dns-discovery-probe__table_agd_33w_33b__entry__2}

| Probe | Description |
|-|-|
| dns | Triggered by 'dns'. Uses 'DNS Name Resolver' Scanner and uses classification 'Process Classification \[discovery_classy_proc\]' |
[Table 2. Port probes]

{#dns-discovery-probe__table_agd_33w_33b}