I would like some help diagnosing a problem with NFS. This is probably caused by some configuration setting that I need to change, but I don't know what that might be.

What I'm seeing is that when I try to mount over NFS when connected via wifi (WLAN0) the mount will always hang forever. Doing the exact same mount over ethernet completes immediately.

Mount command:
sudo mount -t nfs4 192.168.1.176:/photos /mnt/photos

The client is a Raspberry Pi running Raspian Jessie (Linux PIDISPLAY 4.4.34-v7+ #930 SMP Wed Nov 23 15:20:41 GMT 2016 armv7l GNU/Linux). The NFS server is running Ubuntu 16.04 NFS v4.

wesw@PIDISPLAY:~ $ showmount -e 192.168.1.176
Export list for 192.168.1.176:
/export/photos 192.168.1.0/24
/export 192.168.1.0/24

wesw@PIDISPLAY:~ $ rpcinfo -p
program vers proto port service
100000 4 tcp 111 portmapper
100000 3 tcp 111 portmapper
100000 2 tcp 111 portmapper
100000 4 udp 111 portmapper
100000 3 udp 111 portmapper
100000 2 udp 111 portmapper

So it works using ethernet. I would say it is a network configuration error, not related to nfs itself. You need to check how your network was configured (ifconfig ?) and what is the difference.

The problem turned out to be a bad wifi AP. For some odd reason the AP will not route NFS traffic. Time to buy a new AP.

Thanks for posting the resolution! (p.s. thot: maybe you can access&config the AP[?])
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