sm is the ubuntu server. No problems mounting it from CentOS-7.
[root@centos7 /]# mount sm:/MOVIES /Z
[root@centos7 /]# mount
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
devtmpfs on /dev type devtmpfs (rw,nosuid,size=8142140k,nr_inodes=2035535,mode=755)
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,nodev,mode=755)
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.
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fusectl on /sys/fs/fuse/connections type fusectl (rw,relatime)
nfsd on /proc/fs/nfsd type nfsd (rw,relatime)
sm:/MOVIES on /Z type nfs4 (rw,relatime,vers=4.1,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=192.168.100.245,local_lock=none,addr=192.168.100.241)
[root@centos7 /]# ls -1 /Z
007
101GOPRO
A-C
Animation
D-R
S-S
T-Z