I have two machine, an NFS server (RHEL) and a client (Debian). The server has NFS set up, exporting a particular directory:

server:~$ sudo /usr/sbin/rpcinfo -p localhost
program vers proto   port
100000    2   tcp    111  portmapper
100000    2   udp    111  portmapper
100024    1   udp    910  status
100024    1   tcp    913  status
100021    1   udp  53391  nlockmgr
100021    3   udp  53391  nlockmgr
100021    4   udp  53391  nlockmgr
100021    1   tcp  32774  nlockmgr
100021    3   tcp  32774  nlockmgr
100021    4   tcp  32774  nlockmgr
100007    2   udp    830  ypbind
100007    1   udp    830  ypbind
100007    2   tcp    833  ypbind
100007    1   tcp    833  ypbind
100011    1   udp    999  rquotad
100011    2   udp    999  rquotad
100011    1   tcp   1002  rquotad
100011    2   tcp   1002  rquotad
100003    2   udp   2049  nfs
100003    3   udp   2049  nfs
100003    4   udp   2049  nfs
100003    2   tcp   2049  nfs
100003    3   tcp   2049  nfs
100003    4   tcp   2049  nfs
100005    1   udp   1013  mountd
100005    1   tcp   1016  mountd
100005    2   udp   1013  mountd
100005    2   tcp   1016  mountd
100005    3   udp   1013  mountd
100005    3   tcp   1016  mountd

server$ cat /etc/exports
/dir      *.my.domain.com(ro) 

client$ grep dir /etc/fstab
server.my.domain.com:/dir   /dir      nfs tcp,soft,bg,noauto,ro 0 0

All seems well, but when I try to mount, I see the following:

client$ sudo mount /dir
mount.nfs: access denied by server while mounting server.my.domain.com:/dir

And on the server I see:

server$ tail /var/log/messages
Mar 15 13:46:23 server mountd[413]: authenticated mount request from client.my.domain.com:723 for /dir (/dir)

What am I missing here? How should I be debugging this?