---
title: "probe.icloud.com and pong.icloud.com: what they are and what breaks if you block them · Kilobat"
url: "https://kilobat.app/hosts/probe-icloud-com"
description: "probe.icloud.com and pong.icloud.com are iCloud connection testing hosts that Apple added in 2026. What they do, and what blocking them affects."
---

Core networking

# probe.icloud.com and pong.icloud.com

`probe.icloud.com` and `pong.icloud.com` are Apple hosts for “iCloud connection testing”. Apple lists them for every platform, on port 443 over TCP and UDP.

Run by Apple · Ports: 443 TCP and UDP · Checked: 1 November 2026

## Short answer

Apple's iCloud connection testing hosts.

Block with care

Blocking them may affect how Apple devices test their iCloud connection. Apple doesn't say what else depends on them.

Matches

`probe.icloud.com` `pong.icloud.com`

A name with `*.` covers every name under it: `*.push.apple.com` matches `1-courier.push.apple.com`.

## What it serves

Apple's enterprise host list names both in its iCloud section, with proxy support. Apple added them in January 2026.

Apple doesn't describe what the tests measure or how often devices run them.

Kilobat doesn't guess at more than Apple documents.

## What breaks if you block it

Block with care

Blocking them may affect how Apple devices test their iCloud connection. Apple doesn't say what else depends on them.

What breaks if you block it

- iCloud connection tests fail. Apple doesn't document the effect on iCloud services.

With Kilobat Pro and the network filter, you can block a host for every app or for one app: in Connections, select a connection and choose Block. Apple’s own services are never blocked by Kilobat’s [Protection](https://kilobat.app/docs/blocking#protection) lists.

## Apple’s rules for its hosts

Apple’s list, [Use Apple products on enterprise networks](https://support.apple.com/en-us/101555), says that devices open these connections, not Apple’s servers. Apple services fail any connection that uses HTTPS interception, so a proxy that inspects TLS should leave Apple’s hosts alone.

If a firewall allows hosts by name, allowing `*.apple.com` covers most Apple services, Apple says. A firewall that works only with addresses can allow `17.0.0.0/8` for IPv4, and `2403:300::/32`, `2620:149::/32` and `2a01:b740::/32` for IPv6.

To see which app on your Mac opened a connection to this host, use Kilobat’s Connections tab, or the [agent network log](https://kilobat.app/docs/agents#agent-network-log) for AI agents.

## Sources

- [Apple Support: Use Apple products on enterprise networks](https://support.apple.com/en-us/101555)

Checked on 1 November 2026.

## Related

- [metrics.icloud.com](https://kilobat.app/hosts/metrics-icloud-com): Apple's host for iCloud device diagnostics.
- [*.icloud.com](https://kilobat.app/hosts/icloud-com): Apple's iCloud domain. Apple lists *.icloud.com for iCloud services; specific hosts under it have their own pages.