Check packet loss / Check network

Again and again we receive inquiries from customers who have a problem with package loss. This is usually caused by problems in routing or misconfigurations on the customer server. In order to identify such problems quickly and to avoid unjustified fault reports, we have created the following instructions.


What is packet loss?

As the name suggests, packet loss is the loss of data packets on the way from the client/server to the other client/server. With every request from a client to a server, a large number of small data packets are transmitted over the network. If there is a data bottleneck on this transmission route, for example due to overloaded network uplinks, a traffic jam or packet loss can occur. A traffic jam usually does not manifest itself directly in packet loss, but for the most part in a higher transmission time, which is declared in milliseconds (ms) - the transmission time is also called ping/latency.

The path the packet travels from the client to the server is specified by the respective network router. A data packet can take a different way to the server as a way back to the client. On the data center side, we can only influence the way back from the server to the client, not on the way from the client to the server. If, for example, a DSL provider routes the request to our servers via Paris, we can not influence here. We can only define a better route from the server to the client.

 

Tools to detect packet loss

To detect packet loss, the WinMTR tool is best, but tools such as PingPlotter are also very helpful when used correctly. A normal tracert or traceroute via Windows shows the route from the client to the server, but usually not the packet loss, if there is one.

 

In our tutorial we only use the tool WinMTR to show packet loss, which is freely available and very easy to use. After downloading from the WinMTR website, simply start the.exe file and enter the IP address of the server in the text field.



Pressing the Start button sends individual packets in the form of ping requests to the server. The first node is usually the in-house DSL router. Then the following numerous routers of the DSL provider and then the data center router of the own data center. For us, it looks like this:


 

Here you can see from the node decix.accelerated.de our network. Packet loss in front of this node is the responsibility of the DSL provider.


Analysis of WinMTR traceroutes

Packet loss can be visible in several ways in the WinMTR tool, some examples and their meaning:

|------------------------------------------------------------------------------------------|
|                                      WinMTR statistics                                   |
|                       Host              -   %  | Sent | Recv | Best | Avrg | Wrst | Last |
|------------------------------------------------|------|------|------|------|------|------|
|                          hitronhub.home -    0 |   12 |   12 |    1 |    1 |    3 |    1 |
|         83-169-183-71-isp.superkabel.de -    0 |   12 |   12 |   13 |   16 |   18 |   16 |
|      88-134-202-169-dynip.superkabel.de -    0 |   12 |   12 |   15 |   19 |   23 |   19 |
|      88-134-237-153-dynip.superkabel.de -    0 |   12 |   12 |   19 |   25 |   31 |   31 |
|       88-134-202-37-dynip.superkabel.de -    35 |   12 |   12 |   20 |   21 |   26 |   21 |
|                    decix.accelerated.de -    0 |   12 |   12 |   21 |   22 |   25 |   25 |
|            fra4.xe-0-1-0.accelerated.de -    0 |   12 |   12 |   20 |   22 |   25 |   23 |
|                      ipp.ip-projects.de -    0 |   12 |   12 |   20 |   22 |   27 |   24 |
|________________________________________________|______|______|______|______|______|______|
   WinMTR v0.92 GPL V2 by Appnor MSP - Fully Managed Hosting & Cloud Provider

 

The packet loss occurring here at node 88-134-202-37-dynip.superkabel.de is probably due to a hardware firewall of the router. This node therefore does not respond to every packet, but still sends the packets to the server. You can see packet loss here, but this packet loss does not affect the actual network quality.

|------------------------------------------------------------------------------------------|
|                                      WinMTR statistics                                   |
|                       Host              -   %  | Sent | Recv | Best | Avrg | Wrst | Last |
|------------------------------------------------|------|------|------|------|------|------|
|                          hitronhub.home -    0 |   12 |   12 |    1 |    1 |    3 |    1 |
|         83-169-183-71-isp.superkabel.de -    0 |   12 |   12 |   13 |   16 |   18 |   16 |
|      88-134-202-169-dynip.superkabel.de -    0 |   12 |   12 |   15 |   19 |   23 |   19 |
|      88-134-237-153-dynip.superkabel.de -    13 |   12 |   12 |   19 |   25 |   31 |   31 |
|       88-134-202-37-dynip.superkabel.de -    10 |   12 |   12 |   20 |   21 |   26 |   21 |
|                    decix.accelerated.de -    11 |   12 |   12 |   21 |   22 |   25 |   25 |
|            fra4.xe-0-1-0.accelerated.de -    14 |   12 |   12 |   20 |   22 |   25 |   23 |
|                      ipp.ip-projects.de -    13 |   12 |   12 |   20 |   22 |   27 |   24 |
|________________________________________________|______|______|______|______|______|______|
   WinMTR v0.92 GPL V2 by Appnor MSP - Fully Managed Hosting & Cloud Provider

 

In this example, 88-134-237-153-dynip.superkabel.de. This behavior indicates an overload of the Internet node at the DSL provider. Although packet loss occurs, this is not within our sphere of influence. In such a case, we can try to get in touch with the DSL provider, but there is no chance of success.

|------------------------------------------------------------------------------------------|
|                                      WinMTR statistics                                   |
|                       Host              -   %  | Sent | Recv | Best | Avrg | Wrst | Last |
|------------------------------------------------|------|------|------|------|------|------|
|                          hitronhub.home -    13 |   12 |   12 |    1 |    1 |    3 |    1 |
|         83-169-183-71-isp.superkabel.de -    11 |   12 |   12 |   13 |   16 |   18 |   16 |
|      88-134-202-169-dynip.superkabel.de -    14 |   12 |   12 |   15 |   19 |   23 |   19 |
|      88-134-237-153-dynip.superkabel.de -    15 |   12 |   12 |   19 |   25 |   31 |   31 |
|       88-134-202-37-dynip.superkabel.de -    11 |   12 |   12 |   20 |   21 |   26 |   21 |
|                    decix.accelerated.de -    13 |   12 |   12 |   21 |   22 |   25 |   25 |
|            fra4.xe-0-1-0.accelerated.de -    10 |   12 |   12 |   20 |   22 |   25 |   23 |
|                      ipp.ip-projects.de -    12 |   12 |   12 |   20 |   22 |   27 |   24 |
|________________________________________________|______|______|______|______|______|______|
   WinMTR v0.92 GPL V2 by Appnor MSP - Fully Managed Hosting & Cloud Provider


This example indicates a problem with the client itself. Maybe the DSL is overloaded or there is a defect on the DSL router itself.

|------------------------------------------------------------------------------------------|
|                                      WinMTR statistics                                   |
|                       Host              -   %  | Sent | Recv | Best | Avrg | Wrst | Last |
|------------------------------------------------|------|------|------|------|------|------|
|                          hitronhub.home -    0 |   12 |   12 |    1 |    1 |    3 |    1 |
|         83-169-183-71-isp.superkabel.de -    0 |   12 |   12 |   13 |   16 |   18 |   16 |
|      88-134-202-169-dynip.superkabel.de -    0 |   12 |   12 |   15 |   19 |   23 |   19 |
|      88-134-237-153-dynip.superkabel.de -    0 |   12 |   12 |   19 |   25 |   31 |   31 |
|       88-134-202-37-dynip.superkabel.de -    0 |   12 |   12 |   20 |   21 |   26 |   21 |
|                    decix.accelerated.de -    11 |   12 |   12 |   21 |   22 |   25 |   25 |
|            fra4.xe-0-1-0.accelerated.de -    10 |   12 |   12 |   20 |   22 |   25 |   23 |
|                      ipp.ip-projects.de -    13 |   12 |   12 |   20 |   22 |   27 |   24 |
|________________________________________________|______|______|______|______|______|______|
   WinMTR v0.92 GPL V2 by Appnor MSP - Fully Managed Hosting & Cloud Provider

 

This excerpt shows a network problem within our network, presumably the node to the DE-CIX is overloaded. We need this information to check, for example, a comparison with DDOS attacks in the period of packet loss.

|------------------------------------------------------------------------------------------|
|                                      WinMTR statistics                                   |
|                       Host              -   %  | Sent | Recv | Best | Avrg | Wrst | Last |
|------------------------------------------------|------|------|------|------|------|------|
|                          hitronhub.home -    0 |   12 |   12 |    1 |    1 |    3 |    1 |
|         83-169-183-71-isp.superkabel.de -    0 |   12 |   12 |   13 |   16 |   18 |   16 |
|      88-134-202-169-dynip.superkabel.de -    0 |   12 |   12 |   15 |   19 |   23 |   19 |
|      88-134-237-153-dynip.superkabel.de -    0 |   12 |   12 |   19 |   25 |   31 |   31 |
|       88-134-202-37-dynip.superkabel.de -    0 |   12 |   12 |   20 |   21 |   26 |   21 |
|                    decix.accelerated.de -    0 |   12 |   12 |   21 |   22 |   25 |   25 |
|            fra4.xe-0-1-0.accelerated.de -    0 |   12 |   12 |   20 |   22 |   25 |   23 |
|                      ipp.ip-projects.de -    30 |   12 |   12 |   20 |   22 |   27 |   24 |
|________________________________________________|______|______|______|______|______|______|
   WinMTR v0.92 GPL V2 by Appnor MSP - Fully Managed Hosting & Cloud Provider

 

Here you can see packet loss that occurs exclusively on the server or on the way back from the server to the client. Here it is recommended to boot the server into the rescue system in order to exclude a packet loss due to a misconfiguration on the server itself. If the packet loss also occurs in the rescue system, you should perform a traceroute from the server to the client in order to be able to identify possible packet loss on the way back. If nothing is noticeable there, there is probably a fault in the network, for example a defect on the switch. You can send us this error message by e-mail with the WinMTR extract in the attachment.


Report packet loss

If you could not identify the cause of the packet loss or. If you were able to solve the problem yourself, you can contact support@ip-projects.de at any time. We will then reproduce the problem independently with the network management and work out a problem solution. Please do not forget to include the WinMTR Tracert in the error message.
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