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NFSCBD(8)		     System Manager's Manual		       NFSCBD(8)

NAME
     nfscbd -- NFSv4 client side callback daemon

SYNOPSIS
     nfscbd [-p port_number] [-P client_principal]

DESCRIPTION
     nfscbd  runs  on  a client using NFSv4 to handle callback requests from the
     NFSv4 server.  If no nfscbd is running, NFSv4 mounts will still  work,  but
     the server will never issue Open Delegations to the client.

     One callback server and one master server are always started.

     The following options are available:

     -p port_number
	     Specifies what port# the callback server should use.

     -P client_principal
	     Specifies	the  host  based principal name to be used as the target
	     for callbacks over RPCSEC_GSS. For KerberosV, it  must  be  in  the
	     client's  default keytab file.  This client_principal should be the
	     same one specified by the gssname	argument  being  used  by  nfsv4
	     mounts.   If you do not specify this argument, callbacks will still
	     work over AUTH_SYS, which is what many extant servers use even  for
	     RPCSEC_GSS mounts, as of 2009.

     For example, "nfscbd -p 7654 -P root" starts the daemon to handle callbacks
     on  port#	7654  and  is  using  the  host  based	principal  root@<client-
     host>.<dns-domain> as the callback target.

     nfscbd listens for service requests at the port defined by NFSV4_CBPORT  in
     /usr/include/fs/nfs/nfs.h, unless -p has been specified.  For more informa-
     tion  on  what  callbacks	and Open Delegations do, see Network File System
     (NFS) Version 4 Protocol, RFC3530.

EXIT STATUS
     The nfscbd utility exits 0 on success, and >0 if an error occurs.

SEE ALSO
     nfsv4(4), mount_nfs(8)

HISTORY
     First introduced with the experimental nfs  client  for  NFSv4  support  in
     2009.

FreeBSD 15.1			 April 25, 2009 		       NFSCBD(8)
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