First:
From xmon(1),
"BUGS: Xmon only handles TCP socket connections.
UNIX domain sockets and DECnet are not supported."
Thus you might need "xhost +`hostname`".
Force a TCP/IP connection with "DISPLAY=`hostname`:1"
or "localhost:1".
The code doesn't set SO_REUSEADDR, so you might get a
"bind: Address already in use" after restarting it. In this case use
another port with the option "-port" or wait about two minutes.
myhost$ xmonui -display :0 | xmond -server :0 -port 1
myhost$ netstat -a | grep 600
*.6000 *.* [...] LISTEN
*.6001 *.* [...] LISTEN
myhost$ xhost +myhost
myhost$ DISPLAY=myhost:1 xfd -fn fixed
...or "localhost:1", but not ":1" (even not with "xhost +localhost")
............REQUEST: OpenFont
font-id: FNT 03800001
name: "cursor"
............REQUEST: OpenFont
font-id: FNT 0380000b
name: "-*-*-*-R-*-*-*-120-*-*-*-*-ISO8859-1"
............REQUEST: OpenFont
font-id: FNT 03800012
name: "fixed"
All the above was done on an X11R5.