Connection Interrupted

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Connection Interrupted

The message appears mid-game and usually clears by itself. Persistent occurrences point at one of three things.

1. Network packet loss

The most common cause, and not something the server config can fix. Confirm it:

mtr -u -P 28960 YOUR.SERVER.IP

Loss at the final hop is the server's network. Loss partway through is the route.

2. Rate limits

If everyone is affected on a full server, the server may be shaping its own traffic too aggressively:

set sv_maxRate 25000
set sv_fps 20

sv_maxRate 0 means unlimited, which is not always better — it lets the server saturate the uplink and produce loss for everyone. 25000 is a sane public value.

Raising sv_fps above 20 increases snapshot frequency and bandwidth per client roughly linearly. On a 20-slot server, sv_fps 30 costs 50% more upstream. Do not raise it because a forum post said so; measure the uplink first.

3. Server hitching

Check the server console:

Hitch warning: 512 msec frame time

The server stalled and missed snapshots. Causes, in order:

  • Host is oversubscribed. Check load average and steal time.
  • A mod script doing too much work in a single frame.
  • Logging to a slow or full disk. set g_logsync 0 buffers writes instead of flushing each line, which is a real difference on a busy server.

Two log lines are noise and should be filtered before you read anything:

grep -v 'cmdCount\|MAX_PACKET\|Rcon from' server.log | tail -50

cmdCount > MAX_PACKET_USERCMDS means a client sent user commands faster than the server sampled them. It is per-tick spam, not a fault.

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