So I was seeing: -
Operation not permitted
whilst trying to mount a NFS export from my Mac: -
sudo mount -t nfs 192.168.3.5:/macbak /tmp/foobar
Simple solution, thanks to Google: -
...
simply adding -o resvport to the mount_nfs command resolves the above error and successfully mounts the NFS share.
...
which leads me to this: -
sudo mount -t nfs -o resvport 192.168.3.5:/macbak /tmp/foobar
The original article also refers to this: -
PS For the record, I'm using OS X 10.9.5 Mavericks, but the solution remains the same, which is nice :-)