Multiple Macs and Network Flooding?

I always get requests to demonstrate everyday things that I do that may help you out.

If you ‘use’ your various tools, you are bound to develop skills and techniques that can not be taught in a classroom or in a YouTube video.

In this example, I noticed the network was a bit ‘laggy’ and simply started a Wireshark capture, and a conversation between my NVR and my camera filled my screen. This is very odd when you realize that I did not have a span port or tap in use.

When I took a closer look at the [packets, I noticed that the delta time was less than 1 ms, which would mathematically result in 1000 packets per second.

Since all the packets were unique, I knew this was NOT a loop of any kind, but why was this conversation getting flooded across my network.

In the video, you see that I verified that the Mac address the NVR was using was the camera’s Wi-Fi MAC but oddly enough the camera was still responding to the NVR using the wifi mac even though it was using the wired connection.

I show you the odd Wireshark trick, so enjoy, and don’t be afraid to capture a few packets.

FYI. went dyslexic with the Mac address at one point.  I’m sure you will out where. 

Baselining Session – Network Throughput

 Here is another slide from our baselining series that we did the other week.  This one is going to focus on network throughput testing.  I use a couple laptops, and iperf3 software which you can get for free at https://iperf.fr/iperf-download.php

The key message and is to develop a methodology consistency so you can better test your equipment and your network.  I emphasize some sort of sample size; mine happens to be five to start with.  Obviously, the more samples you have the more accurate the values will be.

Even though I use iperf3 in this session, there are many other products that will do the same thing. I just wanted to get those who have never done this, started with something. 

Saturday Stuff: VPN Reference Sheet

 

Internetworks: What is VLAN Trunking? How to configure?

 

A Trunk link is a point-to-point link between two network devices. Trunk links carry more than

one VLAN. With VLAN trunking, we can extend our configured VLAN across the entire

network. Remember, sending information from an access link on one VLAN to another VLAN

is not possible without the additional device a router, or an external layer 2 bridge connected

between the VLAN.

https://www.internetworks.in/2018/12/vlan-trunk.html

Understanding Policy Based Routing (PBR)

 

With Policy Based Routing (PBR), you can set up routing based on criteria other than the destination network; PBR allows you to route traffic based on source address, source port, destination address, destination port, protocol, or a combination of these.

The primary purpose of Policy-Based Routing (PBR) is to provide network administrators with greater flexibility and control over how data packets are routed within a network. This goes beyond the limitations of traditional routing protocols which rely on destination IP addresses.

https://www.thenetworkdna.com/2024/03/understanding-policy-based-routing-pbr.html