---
title: "What rules are required for an external firewall to access the icom Connectivity Suite - VPN?"
slug: "what-rules-are-required-for-an-external-firewall-to-access-the-icom-connectivity"
updated: 2026-06-23T11:54:51Z
published: 2026-06-23T11:54:51Z
canonical: "docs.insys-icom.com/what-rules-are-required-for-an-external-firewall-to-access-the-icom-connectivity"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.insys-icom.com/llms.txt
> Use this file to discover all available pages before exploring further.

# What rules are required for an external firewall to access the icom Connectivity Suite - VPN?

The connection to the icom Connectivity Suite - VPN is established by calling the domain. The router must therefore be able to resolve this using a DNS. UDP port 53 must be opened to be able to reach a DNS server.

UDP port 1196 must be opened to establish a connection to the Init server (is used to download the configuration automatically) of the icom Connectivity Suite - VPN.

If a connection to an NTP server (used to [update the router's system time](/kb/docs/how-to-ensure-a-regular-update-of-the-clock-time)) is required (if your router is located behind an external firewall and you are not using a local time server), UDP port 123 must be opened.

The VPN UDP port (alternatively: VPN TCP port) must also be opened for the productive operation of the router in the **icom Connectivity Suite - VPN**. You can find this in the icom Connectivity Suite on the [My VPN Hub](https://docs.insys-icom.com/kb/docs/icom-connectivity-suite-my-vpn-hub) menu page.