Unable to mount kerberized nfs?

I want to configure kerberized nfs, and export /data/books I have 3 servers: ipa, server, client I configured ipa and added nfs service. My Steps are:

• In ipa:

  ipa service-show nfs/server.linux.rhce.com
  ipa-getkeytab -s ipa.linux.rhce.com -p nfs/server.linux.rhce.com  -k /etc/krb5.keytab
  

• In server:

  scp ipa:/etc/krb5.keytab /etc/krb5.keytab
  semanage fcontext -a -t krb5_keytab_t /etc/krb5.keytab
  restorecon -R /etc/krb5.keytab 
  systemctl start nfs-server
  firewall-cmd --permanent --add-service=nfs
  firewall-cmd --permanent --add-service=mountd
  firewall-cmd --permanent --add-service=rpc-bind
  firewall-cmd --reload
  

  And in /etc/exports

  /data/books   *(sec=krb5p,rw,no_root_squash)
  

• In cleint:

  scp ipa:/etc/krb5.keytab /etc/krb5.keytab
  semanage fcontext -a -t krb5_keytab_t /etc/krb5.keytab
  restorecon -R /etc/krb5.keytab
  

  When I tried to mount the /book/data on the client

  mount -o sec=krb5 server:/data/books /mnt
  

  I got this message:

  mount.nfs: an incorrect mount option was specified
  

Any help!

In /etc/exports you specified sec=krb5p, so that all traffic will be authenticated and encrypted.

But in your mount command, you specified sec=krb5, but this does not match. This must be the same as the option given in /etc/exports.