Redhat: Network Intro
Networks
Networking uses the TCP/IP series if protocols. Its is a layer of protocols origanally developed for UNIX and now adopted by the Internet.
Networks currently use the IPv4 addresses. However, as the Internet has now run out of IPv4 addresses, we are moving forward to IPv6 addressing. Currently IPv4 is used on most systems, but this will change over the coming months and years.
IP addresses can either be statically assigned so that they will always have the same IP address, or they can be leased from a DHCP server. DHCP addresses are oftern refereed to a Dynamic Addresses.
IPv4
IPv4 addresses are made up of four 8 bit binary numbers. These are shown as four decimal numbers seperated by decimal points. As they are 8 but binary numbers, they can represent values from 0 to 255.
172.28.0.2 #IPv4 Address for pxe
10.16.1.1 #IPv4 Address for head nodeIPv4 Network Classes
| A | 1.1.1.1 - 126.255.255.255 | Allows Networks of up to 16 Million Computers |
| B | 128.0.0.1 - 191.255.255.254 | Allows Networks upto 65,000 Computers |
| C | 192.0.0.1 - 223.255.255.254 | Allows Networks up to 254 Computers |
| D | 224.0.0.1 - 239.255.255.254 | Reserved for MultiCasts |
| E | 240.0.0.1 - 255.255.255.254 | Reserved for Experimental Use |
IPv6
The world has now used up all of the IPv4 addresses possible. As such we are now moving to IPv6.
In comparison to IPv4 which has 32 bits, IPv6 uses 128 bits. An IPv6 address is shown has eight groups of 4 hexedecimal numbers.
4abe:03e2:c132:69fa:0000:0000:c0b8:2148IPv6 Network Classes
| Unicast | 48 But network Prefix, 16 bit subnet, 64 bit identifier |
| MultiCast | Used to send messages to multiple network adapters. |
| AnyCast | Used to send messages to one of several adapters. |