IPV4 and IPV6 Flashcards
How long are IPV4 addresses?
32 bits (4 bytes)
What are the two parts to an IP address?
The host part and the network part
What do nodes use a subnet mask for?
To identify which part of the IP address they have in common with all other nodes on a network
Who is responsible for assigning IP addresses
The IANA (Internet Assigned Numbers Authority)
What is the broadcast IP address?
255.255.255.255
What IP address is used by a host which hasn’t been assigned an IP addresses yet?
0.0.0.0
How many bits are IPV6 addresses?
128 bits long
What is DHCP
Dynamic Host Configuration Protocol
What does DHCP do?
Allows PC’s to request an IP address from a server which is configured with a list of available IP addresses
What else can DHCP servers be used to do?
Provide DNS and other gateway services
What are the three ways a DHCP server can be configured?
- Dynamic
- Automatic
- Static
What is dynamic DHCP allocation?
Range of IP addresses used for a controllable amount of time allowing to reclaim and reallocate addresses that are not renewed
What is automatic DHCP allocation?
DHCP assigns an IP address to a requesting client and keeps a list of past IP addresses so it can reassign the same IP address in the past every time
What is static DHCP allocation?
The DHCP server permanently allocates an IP address based on a pre-configured mapping to each clients MAC address.
Why is DHCP so useful?
Because it means that administrators do not need to configure each PC individually
What are the 4 phases of the DHCP negotiation?
- Server discovery
- IP offer
- IP request
- Lease acknowledgement
How does the DHCP server discovery phase work?
A device being booted broadcasts on its local network to find a DHCP server. Using UDP on 255.255.255.255
How does the DHCP IP offer phase work?
DHCP server sends an offer to the client with clients MAC address, IP address on offer, lease time and IP address of DHCP making offer.
How does the DHCP IP request phase work?
The client chooses an IP address from ones on offer and send a DHCP broadcast requesting the IP address it wants to lease
How does the DHCP lease acknowledgement work phase work?
When server sends recieves clients DHCP request packet it sends an acknowledgement of the lease and the DHCP process is complete
What source, destination IP and port does a client use when requesting a DHCP request?
Source IP: 0.0.0.0 and port 68
Destination IP: 255.255.255.255 and port 67
What is DNS?
An automated and distributed network of servers which translates domain names to IP addresses
What is zero configure?
Where there is no DHCP server of manually configured IP address. Client will automatically assign an IP address and send out message to see if anyone else has same IP address on that network
What do Microsoft, apple and linux use for zeroconfig?
Microsoft - APIPA
Apple - Bonjour
Linux - Avahi
In the 167.254.xx.xx range
A class B network has how many possible addresses?
65,536
