"No Protocol Specified" even when I can telnet into the X server port?

I have a Win 11 box running Xming, a binary I've used on Win 7 without issue. Xming is version 6.9, a **32-bit binary** that nonetheless seems to run on 64-bit Linux. However I wonder if its not able to understand incoming protocol due to the bit width being wrong? netstat -an on the Win11 box reports no use of port 6000 (the default X server listening port). I start Xming, and netstat -an now reports port 6000: TCP 0.0.0.0:6000 0.0.0.0:0 LISTENING I have a Fedora 31 box. I can run xeyes with DISPLAY=:0 and get a display on the Linux machine, whether the terminal is an xterm on the Linux machine or a Putty window on Win11. strace xeyes |& less shows the connection is working. Connect() returns 0 (success). It's writing to the socket. File descriptor 3 is the TCP connection, returned by socket(), and it must have been opened as we see it being written to and receiving a little data: an 8-byte header and the string "No protocol specified." socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC, IPPROTO_TCP) = 3 setsockopt(3, SOL_TCP, TCP_NODELAY, , 4) = 0 setsockopt(3, SOL_SOCKET, SO_KEEPALIVE, , 4) = 0 connect(3, {sa_family=AF_INET, sin_port=htons(6000), sin_addr=inet_addr("192.168.11.17")}, 16) = 0 getpeername(3, {sa_family=AF_INET, sin_port=htons(6000), sin_addr=inet_addr("192.168.11.17")}, [124->16]) = 0 access("/home/fs/.Xauthority", R_OK) = 0 openat(AT_FDCWD, "/home/fs/.Xauthority", O_RDONLY) = 4 fstat(4, {st_mode=S_IFREG|0600, st_size=702, ...}) = 0 read(4, "\0\0\0\4\300\250\10\6\0\0010\0\22MIT-MAGIC-COOKIE-1\0"..., 4096) = 702 read(4, "", 4096) = 0 close(4) = 0 fcntl(3, F_GETFL) = 0x2 (flags O_RDWR) fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0 fcntl(3, F_SETFD, FD_CLOEXEC) = 0 poll([{fd=3, events=POLLIN|POLLOUT}], 1, -1) = 1 ([{fd=3, revents=POLLOUT}]) writev(3, [{iov_base="l\0\v\0\0\0\0\0\0\0\0\0", iov_len=12}, {iov_base="", iov_len=0}],2) = 12 recvfrom(3, 0x562bca54c080, 8, 0, NULL, NULL) = -1 EAGAIN (Resource temporarily unavailable) poll([{fd=3, events=POLLIN}], 1, -1) = 1 ([{fd=3, revents=POLLIN}]) recvfrom(3, "\0\26\v\0\0\0\6\0", 8, 0, NULL, NULL) = 8 recvfrom(3, "No protocol specified\n\0\0", 24, 0, NULL, NULL) = 24 write(2, "No protocol specified\n", 22No protocol specified) = 22 shutdown(3, SHUT_RDWR) = 0 close(3) = 0 Further: clicking the Xming icon in the icon tray (lower right corner) and opening log file after such a failed connection reports: AUDIT: client 4 rejected from IP So why can't I connect?