I am dealing with a networking subject with my MMORPG server setup. The server infrastructure is as follows:
Host: Home windows Server
Server Software program and Companies: Hosted inside a Digital Machine operating Debian
Networking: The VM is bridged/NATed (specify as wanted)
For some accounts, sure packets (e.g., packet 0x09a1, 2 bytes in size) are despatched from the consumer (confirmed by native Wireshark and an exterior library hooked into the consumer), however by no means arrive on the server—Wireshark operating on the Debian VM by no means sees them. For different accounts, the whole lot works tremendous and packets are obtained as anticipated.
Technical Particulars
The problematic packets are clearly seen as despatched in native Wireshark captures.
On the server (Debian VM), those self same packets are fully lacking from the seize when utilizing a problematic account.
When evaluating native vs server captures, I generally discover 4 additional bytes added on the finish of the packet (e.g., f7 38 dc d7), for working accounts.
If I modify to a working account ID, the packets are obtained appropriately, and the additional 4 bytes aren't current.
On the applying facet, the related breakpoint is rarely hit, confirming the packet by no means reaches the server logic.
Different TCP site visitors between consumer and server works usually. Solely sure packets with particular account IDs "disappear."
No particular firewall guidelines or community restrictions are configured for particular accounts or packets.
Extra Evaluation
Cloned VM Works: I made an an identical copy of the Debian VM (identical configuration, identical server software program, identical knowledge) and ran it domestically on my machine. On this setup, the whole lot works completely—even for the problematic accounts, each domestically and for exterior customers connecting from exterior.
SSH Forwarding Works: I additionally examined connecting by way of SSH port forwarding to the stay server. When forwarding the emulator ports by way of SSH, the connection works tremendous for these accounts—the lacking packets arrive as they need to.
Suspect: The difficulty appears remoted to the networking path between the consumer and the Debian VM when operating on the manufacturing Home windows Server host. No OS/software logs report dropped packets or errors.
Has anybody skilled a state of affairs the place TCP packets despatched from the consumer by no means arrive on the server, however just for particular account IDs—and solely on a specific Home windows Server + Debian VM setup? Might this be attributable to deep packet inspection, host firewall, virtualization networking settings, or sure offloading options (TCP Offloading, checksum offload, and many others.) on the Home windows Server host?
Any solutions or diagnostic steps can be extremely appreciated!
