Re: Problems with Mac clients mounting a Linux server behind a firewall

[James Pearson <james-p@moving-picture.com>]

James Pearson wrote:
> I'm not absolutely sure if this is an NFS server issue, but I have an
> Linux NFS server running CentOS4 that sits behind a firewall - about
> once a week rpciod ends up using 99% CPU and the machine needs to be
> rebooted
> 
> When it gets into this state, running 'netstat -u -a' shows thousands
> of entries like:
> 
> udp        0      0 *:35071                     *:*
> udp        0      0 *:34815                     *:*
> udp        0      0 *:34559                     *:*
> udp        0      0 *:34303                     *:*
> udp        0      0 *:34047                     *:*
> udp        0      0 *:33791                     *:*
> udp        0      0 *:33535                     *:*
> udp        0      0 *:33279                     *:*
> udp        0      0 *:33151                     *:*
> udp        0      0 *:32895                     *:*
> 
> and tcpdump shows lots of udp connection attempts to port 111 on
> various Macs that are or have mounted the server (via an automounter).
> The connections don't get through as they are blocked by the firewall.
> None of these blocked connections are to Linux clients - it's just Mac
> clients
> 
> Is there anything that NFS server-wise that could be cause the server
> to attempt to contact clients in this way?

Running wireshark over the tcpdump output, all these portmap calls are like:

User Datagram Protocol, Src Port: 51947 (51947), Dst Port: sunrpc (111)
Remote Procedure Call, Type:Call XID:0xacd4150f
Portmap GETPORT Call NLM(100021) Version:4 UDP
     [Program Version: 2]
     [V2 Procedure: GETPORT (3)]
     Program: NLM (100021)
     Version: 4
     Proto: UDP (17)
     Port: 0

Why would an NFS server need to initiate a call to the lockd process on 
a (MacOS) client?

Thanks

James Pearson