Network packets

Network packets

1. Mac Address

   • Short for Media Access Control address
   • This is the unique identifier assigned to a network card or Wi-Fi adapter
   • It is a 48 bit binary number stored within the card hardware itself
   • If you set up a WiFi one of the things you can do to improve security is to only allow devices with certain MAC addresses to connect to the network

2. DNS

   • DNS (Domain Name System) converts a URL (Web Address) to an IP Address
   • This service is provided by your ISP using a DNS Server
   • If the ISP DNS Server does not know the IP Address it will broadcast to other DNS Servers to try to find it

3. Network packets

   • To email a photo, first it is broken down into small packets of data
   • Each packet is then given a header which contains the IP address of the network and device that it is being sent to.
   • Also contains the IP address of the network that it was sent from.
   • Contains the packet number as well as the total number of packets, for example packet 4 of 60, packet 45 of 60.
     • When the packets arrive at the destination this information is used to reassemble the data.