Wiki 9Minecraft Wiki 9Minecraft

Connectivity Mod Wiki & Guide

Java EditionModGuides 4FAQ 20Related mods 48

Connectivity Mod is a technical mod designed to address various issues with network connections to a server (or local game), including problems like login timeouts, DecoderException (decoding exceptions), packet size limits, ghost blocks, payload being too large, and others.

DownloadConnectivity Mod

Get the files on 9Minecraft

Contents (4)
  1. Guides
  2. Frequently asked questions
  3. Gallery
  4. You May Also Like

Guides

Step-by-step, in-game.

Fixing DecoderException and Packet Size Errors with Connectivity ModA DecoderException or a "payload too large" error usually means a packet arrived that the receiving side could not…How to Monitor Network Traffic In-Game with Connectivity Mod CommandsThe Connectivity Mod includes network monitoring so you can see exactly what your client and server are sending. This…How to Use the Connectivity Mod to Diagnose Login and Play TimeoutsWhen you keep getting kicked with a timeout while joining a server, the Connectivity Mod gives you the tools to find…Using Connectivity Mod's Debugging Tools to Track Down a Problematic ModWhen a server or client misbehaves and you do not know which mod is responsible, the Connectivity Mod's debugging…

Frequently asked questions

How do I know if Connectivity Mod is actually running on my server?
Run the mod's network stats command and see if it returns traffic data — if the command isn't recognized, the mod isn't loaded. You can also check your mods list or server log for the mod's startup message.
What command shows my outgoing network traffic?
Use /connectivity packetsClient to see outgoing traffic from the client side. There's a matching server-side command for viewing traffic from the server's perspective.
Why am I getting DecoderException kicks when joining a modded server?
DecoderException usually means a packet was malformed or exceeded the size the connection could handle during login or play. Connectivity Mod logs the offending packet and its source so you can identify which mod is sending bad data.
How do I fix ghost blocks on my server?
Ghost blocks are typically caused by oversized or dropped packets that the client never receives. Enable the mod's packet logging and oversized-packet warnings to find the source, then address the mod or payload causing the issue.

See all 20 Connectivity questions ›