After using nfs to mount the file system, the local area network can be pinged on the development board, but the external network cannot be pinged. This requires setting the routing gateway and dns, as follows:
1. Set the default route: /sbin/route add default gw 192.168.7.1
2, view routing information
3. Set dns ------ Set according to the local dns address: echo nameserver 202.96.128.86 > /etc/resolv.conf
4, ping external network test
