How to Capture and Analyze packets with the tcpdump command on Docker Containers Docker Containers are running on top of Linux so we have more flexibility in capturing the packets that are exchanged between the docker containers. Containerlab at the end of a lab deployment reports that it created the containers with the names Capturing the packets from an interface requires having that interface name and its network namespace (netns) We use the netns command to identify the IP links associated with them and capture the packet for further analysis Using netns command we got the namespace of the container and use namespace and check the link associated with that container in specific Use tcpdump command to capture the packet coming to e1 for analysis Command-List: i p netns ip netns <namespace> ip link Local Capture ip netns exec $lab_node_name tcpdump -nni $if_name Remote Capture ssh $containerlab_host_address "ip netns exec $lab_node_name tcpdump -nni $if_name"
