Free ARP Scanner for your toolbox

I can never stress enough that you need to ‘get to know’ your tools for a bunch of reasons, here are a few examples;

- Understand how the tool behaves on the network

- Ensure that no extra communication is going on

- Better understand when it doesn’t ‘work’

Analyzing Multiple Trace Files- Setup

I get many emails asking for assistance when you have multiple trace files. Lets start with a quick review of the benefits of having multiple trace files: 

• Determine the source of lost packets  
• Determine network latency  
• Determine the source of out of sequence packets 

The hardest part of this process is the setup or preparing your trace files. I try to keep the capture points as consistent as possible. For example, if you have Wireshark installed on your server, I would prefer that you have Wireshark installed on the client computer. If you span the server port, I would prefer we span the client port, that sort of thing.

Common Sense (Paul Smith)

 

According to the Internet, the phrase “Common sense is not so common” originated with a Frenchman – Francois-Marie Arouet – who was a leading figure during the Age of Enlightenment. Francois, who had a knack for catchy phrases, began writing them at the age of 12. Eighteenth Century authorities were not always amused, and he often found himself in and out of the Bastille. He eventually moved to London and adopted the pen name Voltaire.

Sylsog – Use it!!

Syslog is one of those behind-the-scenes network tools that quietly saves the day more often than people realize. Routers, switches, firewalls, servers, and wireless access points are constantly generating useful information, and syslog pulls all those messages together into one centralized location. Instead of jumping from device to device trying to figure out what happened, network administrators can quickly search through logs and spot problems before users even notice something is wrong. It is like having a security camera system for your entire network — except instead of video, you get detailed technical events and alerts.

One of the biggest advantages of syslog is troubleshooting speed. When a network outage or performance issue hits, every second matters. Syslog helps pinpoint exactly when an interface went down, when a DHCP server stopped responding, or when a firewall started blocking traffic unexpectedly. You can follow the timeline of events across multiple devices and connect the dots much faster than relying on guesswork alone. In many cases, syslog can turn a two-hour troubleshooting session into a ten-minute fix, which means less downtime and fewer headaches for everyone involved.

Validating Network Performance with a Throughput Test

The core job of a network is to reliably transport data from one point to another, as quickly as possible. If this is accomplished, end users can experience applications and services without skips, lags, and delays induced by the network.

However, when a problem does strike, engineers want to quickly determine if the blame lies on the network or not. Better yet, they should proactively baseline the network before problems start! One way to do that is to test the network path using tools such as iPerf or the Network Performance Test from NetAlly. Let’s look at both tools and see how they can help us spot network problems quickly.