How to solve "unknown nfs status return value: -1" when trying to mount an NFS drive on AIX on Linux

My error:

[root@mylinuxserver/]# mount -o nfsvers=2 -o nolock mynfsserver:/u01/software /myshare
mount: mynfsserver:/u01/software failed, reason given by server: unknown nfs status return value: -1

Solution: Add the client's ip-address and the name to the NFS servers /etc/hosts file, then retry the mount command.

Share is now mounted and usable:

[root@mylinuxserver/]# df -h -F nfs
Filesystem            Size  Used Avail Use% Mounted on
mynfsserver:/u01/software     705G  654G   52G  93% /myshare

Apparently the error can also be overcome by making sure the client is set up with "reversed lookup" in your DNS server.
In other words, nslookup should be able to resolve both the hostname of the client and the ip address of the client.