Lesson 4: Understanding Internet Protocol

The IPv4 classification system is known as the classful network architecture and is broken down into five sections. Class B has a default subnet mask of 255.255.0.0.

A subnet is a smaller network that is part of a larger network. It is created by dividing a larger network into smaller, more manageable networks. Each subnet has its own unique range of IP addresses and can be used to organize and manage network resources efficiently. Subnets help in reducing network congestion and improving security by isolating different sections of a network.

An IPv6 address is made up of 128 bits. This is a significant increase compared to the previous version, IPv4, which uses 32 bits. The increase in bits allows for a much larger number of unique addresses to be assigned, which is necessary due to the growing number of devices connected to the internet. The 128-bit address space provides a virtually unlimited number of unique addresses, ensuring the continued growth and expansion of the internet.

DNS (Domain Name System) is the correct answer because it is the server used to translate host names to IP addresses. DNS is responsible for resolving human-readable domain names, such as www.example.com, into the corresponding IP addresses, which are numerical identifiers used by computers to communicate over the internet. DNS servers maintain a database of domain name and IP address mappings, allowing users to access websites and other network resources by simply typing in the domain name instead of the IP address.

The default gateway is the IP address of the router that connects a host to other networks. It is responsible for routing the network traffic between different networks. When a host wants to send data to a device on a different network, it checks the destination IP address against its own IP address and subnet mask. If the destination IP address belongs to a different network, the host forwards the data to the default gateway, which then routes it to the appropriate network. Therefore, the default gateway defines the nearest router for a host.

IPv6 addresses are also hexadecimal in format and divided into eight groups of four numbers each, with each group separated by a colon.

The host cannot find a DHCP server because the IP address assigned to the host is in the range of 169.254.0.0 to 169.254.255.255, which is the Automatic Private IP Addressing (APIPA) range. This range is used when a host is unable to obtain an IP address from a DHCP server. Therefore, the host is unable to connect to the server due to the absence of a DHCP server.

Network address translation (NAT) is the process of modifying an IP address while it is in transit across a router, computer, or similar device. This is usually so one larger address space (private) can be remapped to another address space, or perhaps remapped to a single public IP address.

A class C has 8 bits left for hosts. Therefore, 2^8 is equal to 256. But since you cannot use all 0s (network address) and all 1s (broadcast address), a class C will only support up to 254 hosts.

The given IP address, 180.24.45.120, falls within the range of Class B addresses. In Class B, the first two octets represent the network portion, while the last two octets represent the host portion. Since the first octet is between 128 and 191, it indicates that it belongs to Class B. Therefore, the given address is assigned to Class B.

Microsoft developed one type of private range for use on small peer-to-peer Windows networks. This private range, called Automatic Private IP Addressing (APIPA), uses a single Class B network number: 169.254.0.0.

Class D is used for multicasting in IPv4. In IPv4, the address space is divided into five classes: A, B, C, D, and E. Class D addresses range from 224.0.0.0 to 239.255.255.255 and are reserved for multicast addresses. Multicasting allows a single sender to send data to a group of receivers simultaneously. Class D addresses are used for applications such as video streaming, online gaming, and audio conferencing, where data needs to be sent to multiple recipients at the same time.

Private IP addresses are hidden from the Internet and any other networks. They are usually behind an IP proxy or firewall device. Several ranges of private IP addresses have been reserved by the IANA. Private address are 10.0.0.0 to 10.255.255.255, 172.16.0.0 to 172.16.255.255 and 172.31.255.255 and 192.168.0.0 to 192.168.255.255.

The broadcast address is used to communicate with all hosts on the network. It is defined as all host bits are 0 (0000 0000).

A multicast address is used to send a single set of packets to multiple hosts. Unlike a unicast address, which is used to send packets to a specific host, a multicast address allows for one-to-many communication. It is commonly used in applications such as video streaming or online gaming, where multiple recipients need to receive the same data simultaneously. The packets sent to a multicast address are only received by hosts that have joined the corresponding multicast group. This makes multicast more efficient than broadcast, which sends packets to all hosts on the network regardless of their interest in the data.

One example of CIDR would be the IP network number 192.168.0.0/16. The /16 means that the subnet mask has 16 masked bits (or 1s), making 255.255.0.0. Usually, that would be a default Class B subnet mask, but because we are using it with what used to be a Class C network number, the whole address becomes classless.

A dynamic address is assigned by a DHCP server. DHCP stands for Dynamic Host Configuration Protocol, which is a network protocol that automatically assigns IP addresses to devices on a network. When a device connects to the network, it sends a request to the DHCP server, which then assigns a dynamic IP address to that device. This dynamic IP address is temporary and can change each time the device connects to the network.