Subnetting Misc Flashcards

Question

List the range of IPs for Class D

Answer 1

224 to just under 240 Or .11100000 to <.11110000

Answer 2

.11111000 - 11111111

Answer 3

Reserved IPs and Private IPs differ primarily in *scope* and *purpose*: Reserved IPs (like Public IP blocks) are globally reserved by IANA for specific, usually public-facing functions, whereas Private IPs are specific, non-routable ranges (e.g., 192.168.x.x) used strictly for internal communication within local networks. Key Differences: **Scope & Routing**: Private IPs are not routable on the public internet, meaning they only work within a LAN or virtual network. Reserved IPs can include public IP blocks dedicated to specific users/resources. **Accessibility**: Private IPs cannot be reached directly from the internet; they require Network Address Translation (NAT) to communicate externally. **Purpose**: Private IPs are used by homes, offices, and cloud networks for internal devices. Reserved IPs (such as Static or Elastic IPs in cloud environments) are generally intended for fixed, public-facing services. **Examples**: Private IP ranges are Reserved IPs might refer to specific IP blocks assigned to a user by a provider. **Cost**: Private IPs are free. Reserved public IPs (like in cloud providers) often cost money.

Answer 4

10.0.0.0/8 10.0.0.0-10.255.255.255 Because this is 24 bits of address space, that's 2^24, which gives ~16 mill addressesKey Private IPv4 Ranges (RFC 1918): **Large (Class A)**: seen above **Medium/Large (Class B)**: 172.16.0.0 - 172.31.255.255 (20 bits of address space, or 2 ^ 20 = ~ 1mill) **Small/Home (Class C)**: 192.168.0.0 -192.168.255.255 (16 bits, 2^16 = ~65k) Other Important Private/Special Ranges: Carrier-Grade NAT: 100.64.0.0/10 is reserved for large-scale NAT within ISPs. Link-Local: 169.254.0.0/16 is used for automatic private IP addressing (APIPA).

Answer 5

172.16.0.0/20 172.16.0.0–172.31.255.255 **~ 1 mill** IPs (1,048,574)

Answer 6

192.168.0.0/16

Answer 7

**192.0.0.**0/24 so 2^8 -2 = **254** IP addresses Not the same as 192.168.0.0 range bc subnet mask is different. This is 192.0.0.1 - 192.0.0.255. The IP address range 192.0.0.0/24 (which includes addresses from 192.0.0.0 to 192.0.0.255) is reserved for IETF Protocol Assignments and DS-Lite (6to4 Relay Anycast). Specifically, /29 within this range is designated for DS-Lite, according to Netgate Documentation. It's also sometimes referred to as a "bogon" range, meaning it's reserved and shouldn't appear on the public internet, according to IPinfo.io. In networking, DS-Lite (Dual-Stack Lite) and 6to4 Relay (Anycast) are distinct IPv6 transition technologies designed to allow communication between IPv4 and IPv6 networks during the transition period from the former to the latter. However, their approaches and purposes differ significantly. DS-Lite (Dual-Stack Lite) Purpose: Primarily used by Internet Service Providers (ISPs) to provide IPv4 connectivity to customers over an IPv6-only access network, according to Juniper Networks. This helps address the issue of IPv4 address depletion while allowing ISPs to deploy IPv6 infrastructure. Mechanism: DS-Lite encapsulates IPv4 packets within IPv6 packets. This is done by a Basic Bridging BroadBand (B4) element (typically at the customer's router/CPE). The encapsulated packets are then sent over the ISP's IPv6 network to an Address Family Transition Router (AFTR). The AFTR decapsulates the IPv4 packets and performs Network Address Translation (NAT) to a shared pool of public IPv4 addresses before forwarding them to the external IPv4 network. Key Feature: Allows IPv4 clients to access the internet using a shared pool of public IPv4 addresses, performing Carrier-Grade NAT (CGNAT) at the AFTR. 6to4 Relay (Anycast) Purpose: A mechanism for sending IPv6 packets over an IPv4 network when the IPv6 host or network doesn't have native IPv6 connectivity. Mechanism: When an IPv6 packet needs to traverse an IPv4 network, a 6to4 router encapsulates the IPv6 packet within an IPv4 header, with the destination IPv4 address being the IPv4 address of a 6to4 Relay router. Anycast: 6to4 Relay routers were designed to be part of an anycast group using the well-known IPv4 address 192.88.99.1. This means that when a 6to4 router sends an encapsulated IPv6 packet to 192.88.99.1, it's routed to the physically closest 6to4 Relay router within the anycast group. The relay then decapsulates the IPv6 packet and forwards it onto the native IPv6 network. Current Status: While historically important, using the 6to4 anycast prefix has been deprecated due to operational problems.

Answer 8

127.0.0.0/8 127.0.0.0 - 127.255.255.255 and 127.0.0.1 is the universally defined localhost loopback addrs allow software and services on a host to communicated with each other without using physical network hardware used for: * diagnostics * testing * service isolation (testing diff services on diff 127.x.x.x addresses) traffic sent to these addresses never leave the local machine, meaning it's not forwarded by routers

Answer 9

169.254.0.0/16 169.254.0.0-169.254.255.255 "Link-local" and "localhost" refer to distinct concepts in computer networking: **Localhost**: a hostname that refers to the local computer or device itself. It's a symbolic name for the loopback interface, allowing a machine to communicate with itself without sending traffic out to a physical network. Purpose: Primarily used for development and testing. Developers can run web servers, databases, or other applications on their local machine and access them using "localhost" (or its associated IP address, 127.0.0.1 for IPv4 or ::1 for IPv6). This enables testing and debugging without requiring a live network connection or a remote server. Scope: The scope of "localhost" is strictly confined to the individual machine. Can also be used to see if ICMP or TCP is working? **Link-Local Address**: an IP address that is automatically configured on a network interface when no other IP address (static or DHCP-assigned) is available. These addresses are designed for communication only within a single local network segment (a "link"). Purpose: Link-local addresses facilitate communication between devices on the same local network without the need for a DHCP server or manual configuration. They are crucial for automatic address configuration (like IPv6 stateless autoconfiguration) and for protocols like Neighbor Discovery Protocol (NDP), which allows devices to find and communicate with each other on the same link. Scope: The scope of a link-local address is limited to the local network segment. Traffic with a link-local source or destination address cannot be routed beyond that segment.

Answer 10

Class D **224.0.0.0/8 - 239.0.0.0/8*** (16 mill IPs) A reserved range allows routers and other network devices to quickly identify multicast traffic based on the destination IP address, without needing to examine the packet's contents further. (remember, multicast is like diff clients tuning into a radio frequency that they want to hear) *Multicast traffic requires different processing than unicast or broadcast traffic. Routers may use specific multicast routing protocols (like PIM) and forwarding mechanisms for multicast traffic.* *Avoiding Conflicts:* Reserved ranges help prevent multicast addresses from overlapping with unicast or broadcast addresses, ensuring proper routing and preventing potential network instability. *Local Scope Addresses:* The range 224.0.0.0 to 224.0.0.255 is reserved for link-local multicast addresses, used by network protocols for tasks like router discovery and topology maintenance. These addresses are not forwarded beyond the local network segment. *Administratively Scoped Addresses:* The range 239.0.0.0 to 239.255.255.255 is reserved for administratively scoped addresses, which are typically used for private multicast domains within an organization. These addresses are not forwarded outside the organization's network. *Source-Specific Multicast (SSM):* The 232.0.0.0/8 range is reserved for SSM, where receivers explicitly specify the source of the multicast traffic. This allows for more efficient and targeted multicast communication.

Answer 11

Class E 240.0.0.0/4 - 255.0.0.0/4

Answer 12

168 (128 + 32+ 8)

Answer 13

/24 + ... (1 borrowed bit) /25 = 2^1 = 2 subnets (2 borrowed bits) /26 = 2^2 = 4 subnets (128 or 126 hosts) (3 borrowed bits) /27 = 2^3 = 8 subnets (64 or 62 hosts) /28 /29 /30 /31 /32

Answer 14

/16 thru to /30 Class B Subnet Masks (CIDR and Decimal) /16: 255.255.0.0 (Default Class B) /17: 255.255.128.0 /18: 255.255.192.0 /19: 255.255.224.0 /20: 255.255.240.0 /21: 255.255.248.0 /22: 255.255.252.0 /23: 255.255.254.0 /24: 255.255.255.0 /25: 255.255.255.128 /26: 255.255.255.192 /27: 255.255.255.224 /28: 255.255.255.240 /29: 255.255.255.248 /30: 255.255.255.252 A Class B subnet (traditionally a /16 network) stops at /30 in networking because this is the smallest subnet size that allows for functional host communication, leaving no space for further division. Related question. If say, class C only uses 3 bits to define it as such, why can't the subnet mask start at /5? (since only the first three bits of the 8 bits of the first octect is taken) Class C addresses do not start at a /5 prefix (a 5-bit network mask) because they are designed for small, local networks, not massive networks. Defined by a 110 binary prefix ( in the first octet), they use a (24-bit) default mask, reserving 8 bits for host addresses (hosts) rather than the 27 bits a allows.

Answer 15

01100000 (96) That's 010-11111 011-00000

Subnetting Misc Flashcards

(59 cards)