Destination Host Unreachable -Fix Ping Error Message

During my network engineer career, one of the common errors I received while troubleshooting connectivity issues is Destination Host Unreachable.

This error was the cause of my Internet connectivity problems most times.

The same can be true for you too. When you troubleshoot your connectivity problems, the chances of getting this ping reply are very high.

If you learn how to resolve this error by yourself, you can fix most of your Internet connectivity problems yourself. In this tutorial, I will explain everything about this error.

By the first part, you will learn the meaning of this ping reply.

The second part of this article explains the reasons to get the ping reply Destination Host Unreachable.

You will learn how to fix the Destination Host Unreachable ping error in the last part.

What does Destination Host Unreachable Ping Reply Mean?

Before proceeding to the core of this tutorial, let me explain the meaning of this ping reply.

The Destination Host Unreachable error tells that the ping packets from your computer cannot find a route to the destination IP address(destination host).

Now you understand the meaning of this ping reply. However, to learn more about this error, you should ask yourself two questions.

1. Who replied to your device this Destination Host Unreachable message?
   
   
2. Why the ping packets from your computer failed to reach the destination address?

Let me answer the questions one by one. But before I explain the first question, you must learn how the ping operation works.

When you ping an address, this is how it works.

• I am pinging to my blog by typing ping www.corenetworkz.com on command prompt.
  
  
• Ping packets reach the default gateway
  
  
• Checking the ARP table and Routing table
  
  
• Finding a route to the Remote Gateway of the destination IP address
  
  
• Remote Gateway forwards the ping packets to the destination host
  
  
• Remote host reply with an acknowledgment
  
  

Can you tell me the potential sources for a Destination Host Unreachable reply from this ping workflow algorithm?

You can get this reply from two possible sources.

1. Your Default Gateway
   
   
2. Destination Gateway

How do you know whether the reply comes from your default gateway or remote gateway?

Well, it is simple. All you have to do is to analyze the ping reply carefully. Check the format of the message. Two types of error messages are common on Windows devices.

1. Reply from x.x.x.x Destination Host Unreachable
   
   If you see the following format, check the IP address. Most of the time, X.X.X.X must be a remote gateway address. Which shows the error message you received is from the remote gateway.
   
   
2. Destination Host Unreachable
   
   If you don't see an IP address in the error reply, your default gateway sends it.
   
   

Both error formats have different reasons. I will explain the reasons to get either format in the next part.

Reasons to Get the ICMP Error Destination Host Unreachable

Any one of the reasons listed below can get you to the ICMP Echo message Destination Host Unreachable.

1. Your Default Gateway doesn't know the route to the destination IP address
   
   
2. Packet Routing issue on Remote gateway
   
   
3. The destination host might be down
   
   
4. Loose Connection
   
   
5. Wrong Firewall Settings
   
   

One of the frequent questions I received from our readers is whether this error is related to the Operating System like Windows error and Linux error?

The answer is no.

Analyzing the ICMP Echo Destination Host Unreachable

Let me explain why I received this ICMP Echo by analyzing a live example.

Here I send ping packets to the global DNS address 4.2.2.2 to troubleshoot the connectivity problem. The screenshot below shows the reply I received.

Microsoft Windows [Version 6.1.7600]
Copyright (c) 2009 Microsoft Corporation.  All rights reserved.

C:\corenetworkz;ping 4.2.2.2

Pinging 4.2.2.2 with 32 bytes of data:

Destination host unreachable.
Destination host unreachable.
Destination host unreachable.
Destination host unreachable.

Ping statistics for 4.2.2.2:
    Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),

C:\corenetworkz>

Which format is this? It is the second format of the Destination Host Unreachable error. Let me explain how to resolve this error.

How to Fix Ping Error Destination Host Unreachable?

If you do not want to go into the complexity of this ICMP Echo, you can follow the instructions below to resolve the Destination Host Unreachable Ping error message.

1. Disable the firewall
   
   Aggressive firewall settings can cause the destination host unreachable error.
   
   To check whether the firewall is the reason for this issue, disable it on your computer.
   
   Try to access the Internet after disabling the firewall.
   
   
2. Perform a Power Cycle in your Network
   
   
   • Switch off the devices on your network
     
     
   • Disconnect power cables from Modem and Router
     
     
   • Disconnect the Ethernet cables from Modem, Computer, and Router
     
     
   • Reconnect the power and ethernet cables
     
     
   • Power on the Modem and Router after one minute
     
     
3. Disable IPv6 and Test the Connectivity
   
   Sometimes devices fell into the IP version conflicts. Different operating systems have different IP version priorities.
   
   Windows 10 prefer IPv6 to IPv4. The same is true for the major Linux variants like Ubuntu, Fedora, Debian, etc.
   
   However, sometimes devices fail to work properly with IPv6.
   
   Rarely it results in ICMP error messages. We can check it by disabling the IPv6 on your device.
   
   Let us check how to disable the IP Version 6 on a Windows 10 computer and test the issue.
   
   
   • Right-click on the Network Adapter at the system tray
     
     
   • Click on Open Network & Internet settings
     
     
   • Click on Change Adapter options
     
     
   • Right Click on the current connection and click properties
     
     
   • Uncheck the Internet Protocol Version 6 (TCP/IPv6)
     
     
   • Click OK
     
     
   • Reboot your Computer
     
     
   Once you reboot your computer, check for the connection.

About The Author:

Alex George is a Microsoft and Cisco Certified Network Engineer. He has been working as a network engineer for more than ten years.

His Professional Qualifications: CCNA, CCNP, and MCSE.