For troubleshooting deep rooted network issues, you may be accustomed to using tcpdump against a network interface on Linux. This same utility can be used on OpenWrt to troubleshoot network issues. The Opkg Package manager makes this easy to install.
tcpdump comes standard on Ubuntu servers and is an invaluable tool in determining traffic coming in and out of a host. As network infrastructures have become more complex and security conscious, validating network flow from client hosts through potentially multiple proxies and ultimately to a destination host and port has become more important than ever. … Ubuntu: Using tcpdump for analysis of network traffic and port usage