centos and kerberized nfs works fine but only for nfs3

Question

I want to mount a nfs4 kerberized share. I'm on centos7, the kerberos server is Freeipa,the client is centos7. The problem is my configuration is working for nfs3 but not for nfs4. First I put my configuration

/etc/exports

/export         10.2.0.0/24(ro,no_subtree_check,fsid=0,)
/export/public      10.2.0.0/24(ro,no_subtree_check,async,root_squash,nohide,sec=sys)
/export/private     10.2.0.0/24(ro,no_subtree_check,async,root_squash,nohide,sec=krb5p)

/etc/nfsmount.conf

   [ NFSMount_Global_Options ]
    Defaultvers=4
    Defaultproto=tcp
    mountport=4001
    Port=2049

/etc/krb5.conf

#File modified by ipa-client-install

includedir /etc/krb5.conf.d/
includedir /var/lib/sss/pubconf/krb5.include.d/

[libdefaults]
  default_realm = MYREALM.FAKE
  dns_lookup_realm = true
  dns_lookup_kdc = true
  rdns = false
  dns_canonicalize_hostname = false
  ticket_lifetime = 24h
  forwardable = true
  udp_preference_limit = 0
  default_ccache_name = KEYRING:persistent:%{uid}


[realms]
  MYREALM.FAKE = {
    pkinit_anchors = FILE:/var/lib/ipa-client/pki/kdc-ca-bundle.pem
    pkinit_pool = FILE:/var/lib/ipa-client/pki/ca-bundle.pem

  }


[domain_realm]
  .myrealm.fake = MYREALM.FAKE
  myrealm.fake = MYREALM.FAKE
  centos1.myrealm.fake = MYREALM.FAKE

I get my key

echo mypassword|kinit myuser

klist report ok

Now,try to mount the "public" without kerberos+nfs4

mount -t nfs  centos1:/public /mnt/ -vvv
mount.nfs: timeout set for Sat Mar  2 14:23:05 2019
mount.nfs: trying text-based options 'mountport=4001,port=2049,vers=4.1,addr=10.2.0.77,clientaddr=10.2.0.77'

and is ok

Now the "public" without kerberos+nfs3

mount -t nfs  centos1:/export/public /mnt/ -vvv
mount.nfs: timeout set for Sat Mar  2 14:26:41 2019
mount.nfs: trying text-based options 'vers=4.1,addr=10.2.0.77,clientaddr=10.2.0.77'
mount.nfs: mount(2): No such file or directory
mount.nfs: trying text-based options 'addr=10.2.0.77'
mount.nfs: prog 100003, trying vers=3, prot=6
mount.nfs: trying 10.2.0.77 prog 100003 vers 3 prot TCP port 2049
mount.nfs: prog 100005, trying vers=3, prot=17
mount.nfs: trying 10.2.0.77 prog 100005 vers 3 prot UDP port 20048

and is ok

Now the "private" with kerberos+nfs3

mount -t nfs  centos1:/export/private /mnt/ -vvv
mount.nfs: timeout set for Sat Mar  2 14:28:05 2019
mount.nfs: trying text-based options 'vers=4.1,addr=10.2.0.77,clientaddr=10.2.0.77'
mount.nfs: mount(2): No such file or directory
mount.nfs: trying text-based options 'addr=10.2.0.77'
mount.nfs: prog 100003, trying vers=3, prot=6
mount.nfs: trying 10.2.0.77 prog 100003 vers 3 prot TCP port 2049
mount.nfs: prog 100005, trying vers=3, prot=17
mount.nfs: trying 10.2.0.77 prog 100005 vers 3 prot UDP port 20048

and is ok.

The problem is if I try with nfs4

mount -t nfs4  centos1:/private /mnt/ -vvv
mount.nfs4: timeout set for Sat Mar  2 14:29:54 2019
mount.nfs4: trying text-based options 'vers=4.1,addr=10.2.0.77,clientaddr=10.2.0.77'
mount.nfs4: mount(2): Operation not permitted
mount.nfs4: Operation not permitted

I had try also from other client,same error The ipa server report

Mar 02 14:29:12 freeipa.realm.fake krb5kdc[611](info): AS_REQ (8 etypes {18 17 20 19 16 23 25 26}) 10.2.0.77: NEEDED_PREAUTH: [email protected] for krbtgt/[email protected], Additional pre-authentication required
Mar 02 14:29:12 freeipa.realm.fake krb5kdc[611](info): closing down fd 11
Mar 02 14:29:12 freeipa.realm.fake krb5kdc[611](info): AS_REQ (8 etypes {18 17 20 19 16 23 25 26}) 10.2.0.77: ISSUE: authtime 1551533352, etypes {rep=18 tkt=18 ses=18}, [email protected] for krbtgt/[email protected]
Mar 02 14:29:12 freeipa.realm.fake krb5kdc[611](info): closing down fd 11

Why nfs kerberized works only with nfs3? I have tried with firewalld and selinux disabled: same thing.

Answer 1

Solution found,I have edited the /etc/exports as this

/export             10.2.0.0/24(ro,no_subtree_check,fsid=0,sec=krb5p:sys)
/export/private         10.2.0.0/24(ro,no_subtree_check,async,root_squash,nohide,sec=krb5p)
/export/public      10.2.0.0/24(ro,no_subtree_check,async,root_squash,nohide,sec=sys)

Now works perfect.

mount -vvv -t nfs4 -o sec=krb5p  centos1.myrealm.fake:/private /mnt
mount.nfs4: timeout set for Sun Mar  3 09:59:06 2019
mount.nfs4: trying text-based options 'sec=krb5p,vers=4.1,addr=10.2.0.77,clientaddr=10.2.0.77'
umount /mnt
mount -vvv -t nfs4 -o sec=sys  centos1.myrealm.fake:/public /mnt
mount.nfs4: timeout set for Sun Mar  3 09:59:19 2019
mount.nfs4: trying text-based options 'sec=sys,vers=4.1,addr=10.2.0.77,clientaddr=10.2.0.77'