We can mount the export using NFS and use it to our hearts content. However, after roughly five minutes of inactivity on the client side, we can no longer interact with the mounted folder. All requests (ls, cd, etc.) just hang.
- Client: Fedora 28
- Server: Proprietary NAS System running on Windows.
Using Wireshark from the server side, monitoring incoming traffic, once inactivity begins, we can see TCP keepalive packets and all are responded to by the server. This repeats four times every 60 seconds. The 5th request is then a FIN/ACK from the client, which is ACK from the server and FIN/ACK from the server, which is ACK from the client. So it seems to me this is the client terminating the TCP connection.
Here is the export information from the mount command. The mount is specified in the automounter.
x.x.x.x:/export on /mnt/test type nfs (rw,relatime,vers=3,rsize=32768,wsize=32768,namlen=255,hard,proto=tcp,port=20000,timeo=600,retrans=2,sec=sys,mountaddr=x.x.x.x,mountvers=3,mountport=10000,mountproto=udp,local_lock=none,addr=x.x.x.x)
So, I got that maybe the client doesn't want to keep an open TCP connection that isn't being used, but why did it re-establish that connection once the a user on that client begins interacting with that client's folder?