TCP/IP concepts we have seen are applicable to Linux (a version of UNIX, where TCP/IP started)
Some special IP addresses
- localhost 127.0.0.1 (loopback address)
- Internal networks
- Class A 10.0.0.0
- Class B 172.16.0.0 to 172.31.0.0
- Class C 192.168.0.0 to 192.168.255.0
- Machines behind a firewall can use these internal IP numbers to communicate among them.
- Only the firewall machine/device (host) needs to have an IP address valid in the Internet.