Internet basics Flashcards
(18 cards)
What is Internet Protocol address (IP)
A unique numerical identifier assigned to each device connected to a network.
Can be in form IPv4 with 32-bit address
IPv6 with 128-bit address
What is Domain Name System (DNS)
Domain needs to be accessed from public Internet. Each domain is assigned a globally unique name within the DNS
The DNS server are dedicated servers that contain list of domain names and their IP address
What happens when a computer queries a DNS
The computer will ask for the domain name, the server will then respond with an IP address that allow the computer to communicate with
How are DNS server categorised
Segmented into geographical groups or levels
What is a FQDN
Fully Qualified Domain Name
It is a domain name that is completely specified on all labels of the hierarchy
E.g.
www.bbc.co.uk = FQDN
Where does the top of the hierarchy start in FQDN
At the most right
What is internet registries
Organisation that are responsible for allocating IP addresses to specific domain names
What is URL
Used to specify means of accessing a resource and its location across a network.
What is resolving an IP address
When a client sends a DNS query for the domain to its specified DNS server
If the DNS server does not have a record it will either recursively handle the request so can deliver an IP address
OR refers to a DNS server authoritative and refers to a lower-level DNS server
What are data packets made out of
Small data
They have a trailer, payload, header
What does the header contain in the data packet
Recipients address
Sender address
Packet number and total packets
Time to live or hop limit
What does the trailer contain in the data packet
Checksum or Cyclical redundancy test
What is packet switching
Developed to allow communications to be shared so when one communication was unavailable a different one could be used
What is latency
Time taken to transfer a packet
What are routers
Routers forwards data packets from one network to another
How do routers work
They look up the destination IP and finds the best router to forward to
It will continuously do this until it reaches its destination
What are gateways
A gateway is needed where data is travelling from one node to another that uses different protocols.
Or if network uses different transmission medium
How do gateways work
Header data is removed and reapplied with the correct format
