How to Monitor Network Traffic In-Game with Connectivity Mod Commands

The Connectivity Mod includes network monitoring so you can see exactly what your client and server are sending. This is useful when you suspect lag, ghost blocks, or a mod is quietly flooding the connection.

Client-side monitoring

Run /connectivity packetsClient in chat. This shows outgoing traffic from your client. Watch the volume over time — a sudden spike when you open a specific GUI or use a specific item points to the responsible mod. Run it again after the spike to compare counts.

Server-side monitoring

On a server you control, use the server-side stats command to view incoming traffic from all players. This helps you spot one player or one mod generating disproportionate traffic. The mod also warns when oversized data is being sent, so watch chat and console for those warnings.

Interpreting the numbers

You are looking for outliers, not absolute values. A packet type that appears far more often than others, or one flagged as oversized, is the one to investigate. Combine this with the mod's advanced error logging: enable it, reproduce the lag or ghost-block issue, then read the log to see which packet correlates with the problem. Ghost blocks often come from block-update packets that never arrived or arrived malformed.