[CentOS] firewalled NFS

Hi,
I'm trying to setup a firewalled NFS server. I've configured my server
(CentOS 5) using the following parameters
/etc/sysconfig/nfs
MOUNTD_NFS_V1="no"
MOUNTD_NFS_V2="no"
RQUOTAD_PORT=875
LOCKD_TCPPORT=32803
LOCKD_UDPPORT=32769
RPCNFSDCOUNT=64
MOUNTD_PORT=892
STATD_PORT=662
STATD_OUTGOING_PORT=2020
SECURE_NFS="yes"


modprobe.conf:
options lockd nlm_udpport=4001 nlm_tcpport=4001


But it does not mount it:
# mount 172.20.0.150:/tmp/ /mnt/tmp/
mount: mount to NFS server '172.20.0.150' failed: timed out (giving up).

There's anything else I must setup to use fixed ports ?

Thanks,
-- 
Jordi