We have been the target of many DDoS attacks lately which is causing UCON traffic to get backed up as our DDoS protection filters out the attacks. This is causing header mismatch errors to appear in server logs.
We are still looking into the UDP flooding (header mismatch / bad packets) issue. Right now I think it may be due to the ddos protection filters causing a backlog of outgoing data during peak times / ddos attacks which leads to flooding of game servers from many ucon source ports.
The hub connects (as do all ucon connections) to a server using an IP and a source port. A server will only receive data from the one port (40000 to 50000 for PBBans). Basically when the flooding occurs the data isn't being sent from our server at that time. I've even shut down the hub and even restarted the entire server but my game server was still being flooded during those events.
I hope to get it fixed asap but it's proving difficult since it seems to be occurring where I have no control or information and I have to rely on our host to investigate. I've added the source port (Src Port) that is assigned to a server on the server management page so that admins who have firewalls can add filters to only allow incoming traffic based on the source port. Ie 184.108.40.206 port 45625. Use 220.127.116.11 to 18.104.22.168 as the source IP's.