---
title: Host lookup fields
description: None Host lookup fields. Duration required to resolve an IP from hostname. 
url: https://www.elastic.co/elastic/docs-builder/docs/3016/reference/beats/heartbeat/exported-fields-resolve
products:
  - Beats
  - Heartbeat
applies_to:
  - Elastic Cloud Serverless: Generally available
  - Elastic Stack: Generally available
---

# Host lookup fields
None

## resolve

Host lookup fields.
<definitions>
  <definition term="resolve.host">
    Hostname of service being monitored.
    type: alias
    alias to: url.domain
  </definition>
  <definition term="resolve.ip">
    IP address found for the given host.
    type: ip
  </definition>
</definitions>


## rtt

Duration required to resolve an IP from hostname.
<definitions>
  <definition term="resolve.rtt.us">
    Duration in microseconds
    type: long
  </definition>
</definitions>