Centos – RHEL 6 TFTP server on VMware vSphere 5 not accepting files from remote clients

I can put a file successfully from localhost. If I try from another host the client connects and the file is created on the server, but it is empty. The transfer then times out a little later.

On the client I can run one of the following with the same result:

tftp <server> -c put install.log
tftp <server> -c put install.log install.log
tftp <server> -c put install.log /install.log

SELinux is in permissive mode, and IPtables is currently off.

Contents of /etc/xinetd.d/tftpd:

service tftp
{
    socket_type             = dgram
    protocol                = udp
    wait                    = yes
    user                    = root
    server                  = /usr/sbin/in.tftpd
    server_args             = -v -c -s /var/lib/tftpboot
    disable                 = no
    per_source              = 11
    cps                     = 100 2
    flags                   = IPv4
}

/tftproot has got 777 permissions.

In /var/log/messages I get:

Mar 21 17:10:30 <hostname> in.tftpd[29093]: WRQ from <client_ip> filename install.log
Mar 21 17:10:35 <hostname> in.tftpd[29093]: WRQ from <client_ip> filename install.log
Mar 21 17:10:40 <hostname> in.tftpd[29093]: WRQ from <client_ip> filename install.log
Mar 21 17:10:45 <hostname> in.tftpd[29093]: WRQ from <client_ip> filename install.log
Mar 21 17:10:50 <hostname> in.tftpd[29093]: WRQ from <client_ip> filename install.log

Been banging my head against this brick wall all afternoon. Someone please put me out of my misery. I know it will be something really stupid 🙁