RPC services for NFSv4 try to load transport modules for
udp6 and tcp6 by default, even if IPv6 has been disabled in
/etc/modprobe.d. To prevent RPC services such as rpc.mountd
from attempting to start IPv6 network listeners, remove or comment out the
following two lines in /etc/netconfig:
udp6 tpi_clts v inet6 udp - -
tcp6 tpi_cots_ord v inet6 tcp - -