Internet Service Provider (ISP)permitting the computer to access the internet.
Network Interface Card (NIC).
There are three important methods of network traffic:
Address Resolution Protocolthat uses broadcast to map MAC addresses to IP addresses.
Open Systems Interconnection Model.
Represents the bit-level transmission between network nodes over the connection medium.
Data: Bits across the wire (1s and 0s) as pulse of electricity or light.
Data Link Layer handles communications between adjacents network nodes via physical addressing (MAC).
Handles routing messages (packets) via the best route to reach its destination based on IP address.
Defines how data will be sent providing validation and security.
Layers 5-7 are typically managed by the application itself, providing the interface for the user to communicate.
There can be multiple switches within a small corporate network that isolate different department computers and servers.
The benefits of segregation in a larger network:
IPv4 address are 32bit with an octet each consisting of 8 bits (hence the 255.255.255.255 limit).
Example of an
2001:0DB8:AC10:FE01:0000:0000:0000:0000 which can be further compressed to be represented as
The main advantage of IPv6 over IPv4 is the larger address space.
Each segment is represented by 16 bits.
Address Resolution Protocol (ARP).
When requestion a resolution to an address, a member of the LAN network sends out a broadcast on the network to all devices asking for a
Target IP but no
Target MAC address.
The device with the
Target IP would then respond with a Unicast to the original device provide the
Target MAC address that was requested..
TargetMAC address as it is a broadcast
Designates which sections of the IP address apply to the network, and which apply to the host.
192.168.001.101 we could have Network Portion
255.255.255 and Host Portion
.101. Only the
101 part of this address is the host portion, so in the above case we know the network is
192.168.001. The network mask determines the network size and
In this example the
192.168.001.0 - 192.168.001.255.
Note that in a classful network, the
.0 is not a valid IP as it represents a network.
The highest IP in the range isn't used for host assignment as it is consider the
broadcast IP for broadcasting a packet to an entire IPv4 subnet.
broadcast address also cannot be an even number.
Common network masks include
255.0.0.0 where the 255s represent the network portion and the 0s represent the host portion. The are also the submasks of the
A, B and C networks.
network portion means we can have many networks.
host portion defines how many devices or how many portions you can have on your LAN. This is the only part of the address on a LAN that changes.
2^n - 2 where n is the number of host bits.
We subtract 2 addresses for the host ID and the broadcast.
We take an IP address and the subnet mask and use an AND calculation on their respective binary representations to figure out the initial IP in the range.
192.168.100.200 => 11000000 10101000 01100100 11001000 255.255.255.224 => 11111111 11111111 11111111 11100000 (2^5 = 32) ============================================================== 11000000 10101000 01100100 11000000 192.168.100.192 32 addressess = 224 Network Address: 192.168.100.192 Broadcast Address: 192.168.100.223
2^b / n+2 where:
This is a replacement for classful networking.
CIDR blocks are denoted with an IP address followed by a
/n where n is a number between 0 and 32 that notes the side of the
192.168.100.1/24 would be a network that supports 256 host addresses (the last octet).
192.168.100.1/23 would support 512 host addresses and so on and so forth.
Classful networking and CIDR apply to IP assignments, FLSM and VLSM apply to how subnets are assigned within an infrastructure and if the routing protocol send the subnet mask. FLSM is uncommon and has been replaced by VLSM.