NFS mounting problem

I’m using Linux Redhat 7.1 KDE to mount to another volume reside on another Linux Redhat 7.1
KDE.I had set the volume on the target computer as a exported NFS filesystem using ‘Netconf’
and later in my workstation I tried to mount the targeted volume using the Linuxconf .
However It comes these error message
Archiving /etc/fstab -remfs,version office
Archiving /etc/fstab -local,version home-office
executing /bin/mount -t nfs -o exec,dev,fuid, rw acer:/home/acer /mnt/share
*mount rpc:unable to receive;errno=connection refused
*return 32

/mnt/share is my valid mountpoints.
please advise.