How to Use the Connectivity Mod to Diagnose Login and Play Timeouts

When you keep getting kicked with a timeout while joining a server, the Connectivity Mod gives you the tools to find out whether the problem is your connection, the server, or a specific packet.

Check the client-side packet log

Open chat and run /connectivity packetsClient. This prints the outgoing traffic your client is sending. Look for entries flagged as oversized or malformed — those are the packets most likely to be dropped or to stall the handshake. If you see a packet repeatedly retried, that is your bottleneck.

Compare with server-side stats

If you run the server, use the server-side equivalent command to view incoming traffic. A login timeout usually means the server never finished reading the client's handshake, so check whether the client's first packets appear in the server log at all. If they do not, the issue is upstream of the server. If they do but the server never responds, the server is the problem.

Read the warnings

The mod logs warnings when data being sent exceeds safe size limits. These warnings name the source of the oversized payload. A single mod sending huge packets can cause timeouts even on a healthy connection. Disable or update that mod, or ask the server admin to raise its limits if the mod supports it.