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If this is a concern, then it is recommended that you use a port mirror on the switch or use a network tap to capture data. The device is going to give higher priority to delivering the packets than capturing them. Keep in mind that captures from Meraki equipment aren't always going to display 100% of the packets that pass the device. Many times Wireshark can show the server admin that it is, in fact, NOT a network issue, but an issue where the server simply isn't responding to traffic that it's being sent. This guide is going to be diving into some (but not all) moderate to advanced Wireshark filters that can be used to help troubleshoot and narrow down the issue. For a quick rundown of how to get started, refer to the articles below. Meraki provides ample opportunity to gather data through packet capture. The display filter syntax to filter out addresses between 192.168.1.1 – 192.168.1.255 would be ip.addr=192.168.1.0/24 and if you are comfortable with IP subnetting, you can alter the /24 to change the range.Network troubleshooting can be difficult and time-consuming to narrow down issues as they come up, and at some point, everyone will blame the network. One of the best tools that you can utilize is Wireshark, a free and open-source program. However, if the addresses are contiguous or in the same subnet, you might be able to get away with a subnet filter. One time-consuming approach would be to literally type out all the addresses you want to filter on. In this video, I respond to a question from one of my readers who wanted to create a display filter for many IP addresses. In either case, you will need to use a display filter to narrow the traffic down. Even when you have a capture filter, it may be too generic. You may not know what to focus on when you capture packets, resulting in no capture filter. A display filter is configured after you have captured your packets. A capture filter is configured prior to starting your capture and affects what packets are captured. Note that in Wireshark, display and capture filter syntax are completely different. In this video, I review the two most common filters in Wireshark. One of the keys to being an effective network troubleshooter when using a protocol analyzer is the ability to see patterns, which is where filters come into play.
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