On Friday December 29, [EMAIL PROTECTED] wrote: > Does anyone know what causes netstat to show UDP port 800 > as active on a Linux NFS client with 2.2.17 kernel when an NFS filesystem > is mounted? > > Using Debian Linux 2.2 with Kernel 2.2.17 with one NFS filesystem mounted, > I see > the following: > > rsh@lithium [3]$ netstat -n -a -u > Active Internet connections (servers and established) > Proto Recv-Q Send-Q Local Address Foreign Address > udp 0 0 0.0.0.0:800 0.0.0.0:* > > If I unmount the NFS Filesystem, the UDP port disappears. That will be the local port that is used to talk to the NFS server. > > It appears that each NFS mounted filesystem uses a separate UDP > port, and that they count down from port 800. I.e. the first > mount uses UDP port 800, the second UDP port 799. > > "lsof -i" doesn't show this port belonging to any process, and the "-p" > option to netstat > doesn't show any process info either. I assume that this means that it's a > kernel thing > rather than a process level thing. > > A network sniff while mounting and umounting the NFS filesystem > doesn't show any traffic on UDP port 800 - I just see portmapper, mountd > and nfs > traffic. While mounting and unmounting you might not (I'm not sure) but while accessing the filesystem you definately should. You say that you see "nfs" traffic. Each packet has a source port and a destintation port. For an NFS request, the destination port will be 2049 on the server, the source port will be 800 (or 799 ...) on the client. > > Does anyone know what this is or where I can look in the source for more info? > I've searched /usr/src/linux/fs/nfs/*.c for 800 and 320 (800 in hex) > without success. Check out net/sunrpc/xprt.c:xprt_bindresvport NeilBrown > > Roy Hills > -- > Roy Hills Tel: +44 1634 721855 > NTA Monitor Ltd FAX: +44 1634 721844 > 14 Ashford House, Beaufort Court, > Medway City Estate, Email: [EMAIL PROTECTED] > Rochester, Kent ME2 4FA, UK WWW: http://www.nta-monitor.com/ > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to [EMAIL PROTECTED] > Please read the FAQ at http://www.tux.org/lkml/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
