On Tue, 2011-07-05 at 22:13 -0400, Tom H wrote: > On Tue, Jul 5, 2011 at 1:11 PM, Rob Kampen <rkampen at kampensonline.com> wrote: > > Boris Epstein wrote: > >>> > >>> Is the OS X firewall blocking nfs? > >>> > >>> How are you mounting the export? If you're not trying it from within > >>> Terminal, does it work from within it? > >> > >> The OS X firewall dos not appear to be a factor. Actually it works > >> just fine when I turn off the firewall on the CentOS end. > >> > >> Could it be that even when I am trying to mount over the TCP the NFS > >> client on the Mac OS X side still tried to connect to some UDP port? I > >> am asking that because everyone else mounts just fine with the > >> firewall up on the server end. > > > > As I recall OS X only does NFS via TCP - other clients can use UDP - make > > sure your CentOS firewall has the TCP ports open. > > OS X does use TCP but I've just run tcpdump on an F15 VM while > mounting and unmounting an NFS share from my Mac. Both the mount and > umount result in four UDP packets, two to the portmapper and two to > random ports. > > I don't have time to experiment further right now but perhaps opening > up 111 UDP will allow your Macs to mount the NFS shares. NFSv3 uses the nfs port (TCP or UDP), portmapper (UDP) and some random UDP ports for quota, lockd, mount, and statd. These random ports can be fixed by setting them in /etc/sysconfig/nfs. They are normally commented out, but uncommenting them (and setting them to different values if so required) will fix them so you can firewall them. Louis