Network Performance Troubleshooting

Techniques to aid with network troubleshooting.

Network Troubleshooting Quick Reference Guide

Quick reference Guide to Network TroubleShooting.   Read More

Troubleshooting Overview

Network Troubleshooting can be quite difficult. Here are some tips to help get you started.  Read More

Network Performance Expectations

How to determine the speed of your network.  Read More

Packet Loss

There are a number of possible causes for packet loss, some are easy to address, some much more difficult.   Read More

Buffer Issues

A common source of packet loss is network devices that can not handle larger bursts of packets. These devices include switches, routers, and security appliances. If you experience moderate loss (e.g.: 300-1000 packets in a 10 second test) it is likely due to a small buffer somewhere in the path. There are two ways to test if you have such a device in your path: use packet pacing to see if there…  Read More

Evaluating Network Performance

Information on reviewing performance data, and setting expectations.   Read More

Interface Speed Mismatch Issues

Sending data from a faster host to a slower host may produce strange measurement behavior. Learn how to identify this problem.   Read More

Host Issues

Here are some other things to look at: Use netstat -s to see if there are a lot of TCP retransmissions. TCP retransmits usually indicate network congestion, but can also happen with bad network hardware, or misconfigured networks. You may also see some TCP retransmissions if the sending host is much faster than the receiving host, but TCP flow control should make the number of retransmits…  Read More