Cisco advanced routing with Switching (Cisco section) 5th Day

Day 05

1. What is NAT? What are the implementation methods?

NAT (Network address translation): By translating the private IP address of the internal network into the world's only public IP address, the internal network can
To connect to an external network such as the Internet.
How NAT is implemented:
The corresponding relationship of the IP address is one-to-one, and is constant, with the help of the static transformation, it can realize some specific service in the external network.
Access to the service provider.
Dynamic conversion: The correspondence between IP addresses is indeterminate, but random, and all private addresses authorized to access the Internet can be randomly
Convert to any of the specified legitimate external IP addresses
Port multiplexing: By changing the source IP address and source port of the out-of-Office packet and port translation, all hosts on the internal network can
Share a legitimate IP address to achieve Internet access and conserve IP.

2. What is the specific idea of troubleshooting when you access http://www.tmooc.cn from a browser?

1.ipconfig View the current network configuration;
2.ping 127.0.0.1 Check whether the native TCP/IP protocol is installed successfully;
3.ping gateway address to verify connectivity to external network exits;
4.ping DNS server address verifies whether the intranet can find a DNS server;
5.ping domain name, verify that the DNS server is able to parse successfully (example: Ping www.tmooc.cn);

Cisco advanced routing with Switching (Cisco section) 5th Day