在 archlinux 客户端上，我尝试连接到 QNAP nfs 导出。导出为 nfsv4。showmount 显示正确的导出：
[root@helene j]# showmount -e 192.168.111.1
Export list for 192.168.111.1:
/Public *
/media 192.168.111.2
Nmap显示
[root@helene j]# nmap -Pn 192.168.111.1
Starting Nmap 7.92 ( https://nmap.org ) at 2022-06-04 09:29 CEST
Nmap scan report for daphnis.kingma (192.168.111.1)
Host is up (0.00039s latency).
Not shown: 984 closed tcp ports (reset)
PORT STATE SERVICE
22/tcp filtered ssh
80/tcp filtered http
111/tcp filtered rpcbind
139/tcp filtered netbios-ssn
443/tcp filtered https
445/tcp filtered microsoft-ds
873/tcp filtered rsync
2049/tcp filtered nfs
3493/tcp filtered nut
5900/tcp filtered vnc
8080/tcp filtered http-proxy
8081/tcp filtered blackice-icecap
8088/tcp filtered radan-http
8089/tcp filtered unknown
30000/tcp filtered ndmps
49152/tcp filtered unknown
尝试挂载结果如下：
[root@helene j]# mount -t nfs 191.168.111.1:/media /srv/media
mount.nfs: Connection timed out
ping 需要 0.5ms。