nfs上的udp800端口

前段时间做nfs server，在客户端上mount一个nfs，结果发现会有800的udp端口开放，通过抓包，发现是和nfs server通信用的，这个端口使用lsof -i和ps -p都找不到相应的程序，最后是google了一下。


> >
> > 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.