August 24, 2021

Wireshark Trace File Reporting Using Excel

Wireshark Trace File Reporting Using Excel
If you have ever opened a large Wireshark capture file and thought, “There has to be an easier way to see what is happening here,” you are not alone. A packet capture contains an incredible amount of information, but sometimes the packet list itself makes it difficult to visualize a problem. One technique I like to demonstrate is taking data from a Wireshark trace file and turning it into an Excel graph. Instead of scrolling through thousands of packets, you can transform the data into a simple visual representation that makes changes in packet rate, traffic volume, delays, or other measurements much easier to spot.

August 18, 2021

How to Configure a Cisco Router as a DHCP Server

How to Configure a Cisco Router as a DHCP Server

When I'm building an isolated network for a class, lab, or troubleshooting exercise, one of the first things I need is a DHCP server. Manually configuring an IP address on every device works, but it quickly becomes tedious and introduces opportunities for duplicate addresses, incorrect subnet masks, or simple typing mistakes. DHCP is particularly useful when the network contains laptops, smartphones, tablets, wireless devices, or other equipment that may be connected temporarily. A Cisco router can handle this job without requiring a separate DHCP server, which makes it a convenient option for small networks and lab environments.

August 13, 2021

Grappling with Tech (Paul Smith)

 

Grappling with Tech (Paul Smith)

It is sometimes said that we don’t choose technology, it chooses us. It is certainly possible to live in today’s world without a cell phone, a computer, or a car but it would require individuality and resolve. Whether you are an early adopter, a late-comer, or a total Luddite, sooner or later technology will hunt you down.

August 09, 2021

Which port is he on ??

Which port is he on ??

 I run into this quite often where the client isn't sure which port the client is connected to.

In many cases, I do not have access to their network management system, or the network is down or worse, the documentation is dated and inaccurate. I think every network analyst should know how to do basic tasks like this one.

August 05, 2021

Wireshark Time Column: How to Use Packet Timing for Network Troubleshooting (Chris Greer)

Troubleshooting with the Time Column in Wireshark (chris greer)

Hey Packet People!

When troubleshooting a network problem with Wireshark, it is easy to concentrate on packet addresses, protocols, and conversations while overlooking one of the most useful pieces of information on the screen: time. The Time column can tell you much more than simply when a packet was captured. With the right configuration, it can help reveal delays, gaps in communication, retransmissions, and the sequence of events that led to a problem. If you are trying to understand why an application feels slow or why a TCP conversation is taking longer than expected, packet timing can be a very useful clue.

August 03, 2021

Layer 1 – gets them all the time, PoE camera network cable troubleshooting

Layer 1 – gets them all the timeI was doing some work on-site when the client asks me if I can help with his IP cameras.

The vendor helped over the phone and they determined that 2 cameras probably need to be replaced. The client explained that he is not that technical and wanted someone else to take a look before he goes through all the trouble of taking them down and sending them back.

I started with a quick look around and determined that the camera is POE and the cable runs to a patch panel, then to the DVR, which is also providing the POE.

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