After the upgrade to Ubuntu 8.10, the network configuration is a little different, and finally it is done,
The result of filling in 255.255.255.0 In the prefix is "OK", which is dimmed and cannot be clicked. After a long time, I found this article on the Internet: prefix. The variable is configured as the number of digits used by the subnet, each byte of the IP address is 8 bits. If the subnet mask is 255.255.255.0, the first three bytes (24bit) are used to specify the network number. If the network mask is 255.255.255.255.240, he uses the first 28bit to specify the network number. Generally, the 24bit prefix is used by the DSL and cable ISP (internetservice providers Internet Service Provider). In our example (prefix = 24), The subnet mask is 255.255.255.0, adjust the prefix variable according to your network conditions.
Enter 24. The network connection is normal. It is still uncertain to fill in the DNS.
There is another problem that cannot be resolved. The final solution is to find that the IP address of the water source is 202.120.58.161.
Add/etc/resolv. conf
Nameserver 202.120.2.101
Solved.