Follow the Bouncing Ball; Finding Your Packets

by | 15 Apr 2021

One of the great strengths of VNS3 has always been the ease with which you can look at your network traffic, a necessity for troubleshooting connectivity issues or attesting to correct packet flow. With our release of VNS3 5.0 we have added some big functional improvements that make our network sniffer even better. 

Where as the network sniffer used to run in a single user, single process mode, you can now run multiple captures in multiple web sessions. This is extremely helpful when multiple people are logged into a controller diagnosing issues together or you want to flip back and forth between two captures running simultaneously. In addition all filtered expressions are now saved so that they can be rerun in the future. You don’t have to reacquaint yourself with filter syntax every time.

Another big improvement is the ability to run a capture across all interfaces. This new functionality allows you to follow a packet, for example, coming off of a IPSec tunnel, up to a container running a proxy load balancer and out to a compute host connected via the encrypted overlay network. This operation would look at three interfaces, eth0, plugin0 and tun0. This is really helpful when observing the full path of your packets.

If you want to take the output of your captures and analyze them in other tools we now provide you the ability to download your captures in pcap format so that you can read them into your preferred network analysis tool or SIEM. There are a number of free online tools like or opensource projects like wireshark and tshark that you can use.

One more improvement that we have made is that all captures will automatically terminate after onehour of running. Previously captures would run until you purposefully stopped them. That ran the risk of over logging and some reduction in performance. Much easier to stop them automatically after a reasonable hour than to have to remember to manually do so.

Ultimately a network device is only as good as the visibility it provides. We at Cohesive Networks strive to provide as much insight as possible and the user experience to make it as simple as possible.