Can't mount NFS volume on RH7.2

Can't mount NFS volume on RH7.2

Post by Vinod Gupt » Mon, 25 Feb 2002 14:03:44



I have added port 2049 (nfs) in the firewall rules in my RH7.2 box
but still while trying to mount -t nfs remote_host:/dir /mnt/nfs
fails with the error mount: RPC: Timed out

Yes, portmap is running on local machine and nfsd on the remote.
In fact, I had installed RH7.2 on my local machine using bootnet
floppy via NFS exported remote_host:/dir a few minutes back.

What else need to be done on client side?
Thanks for help.

Vinod.

 
 
 

Can't mount NFS volume on RH7.2

Post by Francis Litteri » Tue, 26 Feb 2002 11:55:39



> I have added port 2049 (nfs) in the firewall rules in my RH7.2 box
> but still while trying to mount -t nfs remote_host:/dir /mnt/nfs
> fails with the error mount: RPC: Timed out

> Yes, portmap is running on local machine and nfsd on the remote.
...
> In fact, I had installed RH7.2 on my local machine using bootnet
> floppy via NFS exported remote_host:/dir a few minutes back.

It sounds like the firewall on the local machine is blocking outbound
TCP traffic to your NFS server.  You can try to open those ports in your
OUTPUT chain, but you can never know the port number on which mountd is
listening on the NFS server.  It can change every time you boot the NFS
server (actually, ever time you stop and start the NFS daemons).

Try this on your NFS client machine:

        ipchains -F output
        ipchains -P output ACCEPT

or if you are using iptables:

        iptables -F OUTPUT
        iptables -P OUTPUT ACCEPT
--
Francis Litterio


 
 
 

Can't mount NFS volume on RH7.2

Post by Robert Myer » Tue, 26 Feb 2002 23:31:54





> > I have added port 2049 (nfs) in the firewall rules in my RH7.2 box
> > but still while trying to mount -t nfs remote_host:/dir /mnt/nfs
> > fails with the error mount: RPC: Timed out

> > Yes, portmap is running on local machine and nfsd on the remote.
> ...
> > In fact, I had installed RH7.2 on my local machine using bootnet
> > floppy via NFS exported remote_host:/dir a few minutes back.

> It sounds like the firewall on the local machine is blocking outbound
> TCP traffic to your NFS server.  You can try to open those ports in your
> OUTPUT chain, but you can never know the port number on which mountd is
> listening on the NFS server.  It can change every time you boot the NFS
> server (actually, ever time you stop and start the NFS daemons).

> Try this on your NFS client machine:

> ipchains -F output
> ipchains -P output ACCEPT

> or if you are using iptables:

> iptables -F OUTPUT
> iptables -P OUTPUT ACCEPT
> --

Whether this works or not will depend on how the rest of  ipchains or
iptables is set up.  It's just as likely that the machine on the receiving
end is blocking the input, and it can (apparently) be legal input from any
port on the host machine at all.

One way to tell what's going on is to use "tcpdump -i eth0" to watch what's
going on ( assuming you have tcpdump installed on your machine; if not, it's
worth installing).   If you get something like (can't remember the exact
wording) "Port xxxx" unreachable", it's probably because the firewall is
blocking the NFS data stream on input.  One (and perhaps the only) way
around this is to tell the blocking machine to accept all input from one or
more machines, regardless of port number, which would mean adding a line to
the ipchains file like

-A -input -s another.ip.address -j ACCEPT

 
 
 

Can't mount NFS volume on RH7.2

Post by Francis Litteri » Wed, 27 Feb 2002 02:55:45



> "Francis Litterio" wrote

>> > I have added port 2049 (nfs) in the firewall rules in my RH7.2 box
>> > but still while trying to mount -t nfs remote_host:/dir /mnt/nfs
>> > fails with the error mount: RPC: Timed out

>> > Yes, portmap is running on local machine and nfsd on the remote.
>> ...
>> > In fact, I had installed RH7.2 on my local machine using bootnet
>> > floppy via NFS exported remote_host:/dir a few minutes back.

>> It sounds like the firewall on the local machine is blocking outbound
>> TCP traffic to your NFS server.
> It's just as likely that the machine on the receiving
> end is blocking the input

Well, the OP said:

Quote:> In fact, I had installed RH7.2 on my local machine using bootnet floppy
> via NFS exported remote_host:/dir a few minutes back.

so I think the NFS server is not blocking inbound NFS traffic.
--
Francis Litterio

PGP public keys available on keyservers.
 
 
 

Can't mount NFS volume on RH7.2

Post by Robert Mye » Wed, 27 Feb 2002 13:14:45




> > "Francis Litterio" wrote


> >> > I have added port 2049 (nfs) in the firewall rules in my RH7.2 box
> >> > but still while trying to mount -t nfs remote_host:/dir /mnt/nfs
> >> > fails with the error mount: RPC: Timed out

> >> > Yes, portmap is running on local machine and nfsd on the remote.
>  ...
> >> > In fact, I had installed RH7.2 on my local machine using bootnet
> >> > floppy via NFS exported remote_host:/dir a few minutes back.

> >> It sounds like the firewall on the local machine is blocking outbound
> >> TCP traffic to your NFS server.

> > It's just as likely that the machine on the receiving
> > end is blocking the input

> Well, the OP said:

> > In fact, I had installed RH7.2 on my local machine using bootnet floppy
> > via NFS exported remote_host:/dir a few minutes back.

> so I think the NFS server is not blocking inbound NFS traffic.

Well, I've actually been through this *exact* scenario (network
install via NFS using a bootnet floppy, followed by an attempt to
mount a volume using NFS) and the firewall installed by anaconda
(using the configuration I requested, of course, which allowed
appropriate access for the daemons relevant to NFS) blocked the
incoming NFS traffic so that I could not mount an NFS volume.

I would have been clearer if I had said "the local machine" rather
than the "machine on the receiving end," since by that I meant the
local machine in the mode of receiving data from the NFS server.  In
fact, with tcpdump, I watched my newly-installed OS send out an NFS
request from an arbitrary port, only to refuse the response from the
server on that same port.

Did you really think I meant the remote NFS server wasn't working?

 
 
 

Can't mount NFS volume on RH7.2

Post by Francis Litteri » Thu, 28 Feb 2002 02:33:50



> Did you really think I meant the remote NFS server wasn't working?

Yes.  I was reading carelessly.

Vinod, Robert's suggestion is far better than mine.  Sorry for any
confusion.
--
Francis Litterio