6. IPv4 Addressing Flashcards
What are the value range and the block size of IPv4?
- 0 - 255
- 4
- 10.0.255.255
What portion does IPv4 made up of? ( 2 )
- Network Portion
- Host Portion
- It is a 32 bit hierarchial address
How to determine the host portion and the network portion
192.168.10.23
- 192.168.10 is Network Portion
- .23 is Host Portions
What is used to determine the network and host portions?
- Subnet mask
What is the actuall process used to identify the network and host portions called?
- ANDing
What is a prefix length used for?
- It is a less cumbersome method used to identify a subnet mask
How to calculate the prefix length?
- Count the number of 1 in the subnet mask
- 255.0.0.0 ( 11111111.00000000.00000000.00000000 ) which has a prefix of 8
How does the prefix length written in ?
- Slash Notation ( /8 )
List out 3 types of IP addresses within each network
- Network Address ( For whole LAN network )
- Host Address ( For end users )
- Broadcast Address
How many devices does Unicasts sends?
- A packet to one destination IP address
How many devices does Broadcast sends?
- A packet to all other destination IP address
How many devices does Multicast sends?
- A packet to a multicast address group ( Send to PC1 , PC3 and PC5 without sending to PC2 and PC4 )
List out 2 types of IPv4 address
- Private
- Public
What are the characteristics of Private IPv4?
- Private IPv4 addresses are not unique and can be used internally within any network
- Are not globally routable
What is Private IPv4 Addresses used?
- It is a common block of addresses used by most organizations to assign IPv4 addresses to internal hosts
What translates private IPv4 addresses to public IPv4 addresses?
- Network Address Translation ( NAT )
Where is NAT typically enabled?
- On the edge router connecting to the internet
List out 2 special use IPv4 addresses
- Loopback Addresses
- Link-Local Addresses
What is the range for Loopback addresses?
- 127.0.0.0/8 ( 127.0.0.1 to 127.255.255.254 )
- Commonly identified as only 127.0.0.1
What is the range for Link-Local addresses?
- 169.254.0.0 /16 (169.254.0.1 to 169.254.255.254)
What is Loopback addresses used for?
- Used on a host to test if TCP/IP is operational
What is Link-Local Addresses are commonly known as?
- Automatic Private IP Addressing ( APIPA ) addresses or self-assigned addresses
What is Link-Local addresses used for?
- Used by Windows DHCP clients to self-configure when no DHCP servers are available
List out 5 IPv4 addresses class by RFC 790 ( 1981 )
- Class A ( 0.0.0.0/8 to 127.0.0.0/8 )
- Class B ( 128.0.0.0 /16 – 191.255.0.0 /16 )
- Class C ( 192.0.0.0 /24 – 223.255.255.0 /24 )
- Class D ( 224.0.0.0 to 239.0.0.0 )
- Class E (240.0.0.0 – 255.0.0.0)
- Classful addressing wasted many IPv4 addresses
Who manages ( 1. ) and allocates blocks of IPv4 and IPv6 addresses to five what ( 2. ) ?
- Internet Assigned Numbers Authority ( IANA )
- 5 Regional Internet Registries ( RIRs )
What is the responsibilty for RIRs ?
- Allocating IP addresses to ISPs who provide IPv4 address blocks to smaller ISPs and organizations
List out all 5 RIRs
- North America - ARIN
- South America - LACNIC
- Africa - AfiNIC
- Eroupe - RIPENCC
- Asia - APNIC
What mode does many protocols used? ( 2 )
- Broadcasts
- Multicasts
- ARP use broadcasts to locate other devices, hosts send DHCP discover broadcasts to locate a DHCP server
What device can stop broadcasts?
- Router
- It do not propagate broadcasts
- Each router interface connects to a broadcast domain and broadcasts are only propagated within that specific broadcast domain
What is the problem with a large broadcast domain
- The hosts can generate excessive broadcasts and negatively affect the network
What is the solution for the problem with large broadcast domain?
- Reduce the size of the network to create smaller broadcast domains in a process called subnetting
- From one router top many switch to maybe one router 2 switches seprately
List out the 3 reasons for segmenting networks
- Subnetting reduces overall network traffic and improves network performance
- It can be used to implement security policies between subnets
- Subnetting reduces the number of devices affedted by abnormal broadcast traffic
- It was also used for a variety of reasons including by :
1. Location
2. Group of Function
3. Device Types
What is the most easily subnetted ( slash notation )
- /8 , /16 & /24
- It is the most easily subnetted at the octet boundary
What will happen when we are using longer prefix lengths?
- Decreases the number of hosts per subnet
What does Enterprice networks will have? ( 2 )
- Intranet ( Private IPv4 Addresses )
- DMZ ( Public IPv4 Addresses )
How many subnets does /25, /26 and /27 have if we are dividing the /24 network?
- /25 - 2 Subnets
- /26 - 4 Subnets
- /27 - 8 Subnets
Which class of IP address can’t be used and it was reserved for loopback testing?
- Class A addresses ( 127.0.0.0 to 127.255.255.255 )
What are the 2 considerations when planning subnets?
- The number of host addresses required for each network
- The number of individual subnets needed
What must we always begin with when we are using VLSM for subnetting?
- Always begin by satisfying the host requirements of the largest subnet and continue subnetting until the host requirements of the smallest subnet are satisfied
What is crucial to develop a scalable solution to an enterprise network?
- IP network planning
What actions do we need to do after examinating an organization’s network usage and how the subnets will be structured?
- Perform a network requirement study by looking at the entire network to determining how each area will be segmented
- Determine how many subnets are needed and how many hosts per subnet
- Determine DHCP address pools and Layer 2 VLAN pools
List out the 5 different types of devices that require addresses
- End User Clients
- Servers & Peripherals
- Servers that are Accessible from the Internet
- Intermediary Devices
- Gateway
- It is generally recommended that we have a set pattern of how addresses are allocated to each type of device
How does End User Clients assign addresses?
- Most use DHCP to reduce errors and burden on network support staff
- IPv6 clients can obtain address information using DHCPv6 or SLAAC
How does Servers & Peripherals assign addresses?
- Should have a predictable static IP address
How does Servers that are accessible from the internet assign addresses?
- It must have a public IPv4 address, most often accessed using NAT
How does Intermediary Devices assign addresses?
- Devices are assigned addresses for network management, monitoring, and security
How does Gateway assign addresses?
- Routers and firewall devices are gateway for the hosts in that network