Introducing the TCP/IP Internet Layer, IPv4 Addressing, and Subnets Flashcards
Provides information on the desired quality of service
Service type
Limits the lifetime of a packet
Time to Live (TTL)
Specifies the 32-bit binary value that represents the IPv4 address of the sending endpoint
Source address
Specifies the 32-bit binary value that represents the IPv4 address of the receiving endpoint
Destination address
Describes the version of IP
Version
Describes the length of the header
Internet Header Length (IHL)
Describes the length of a packet, including header and data
Total Length
Used for unique fragment identification
Identification
Sets various control flags regarding fragmentation
Flag
Indicates where a specific fragment belongs
Fragment Offset
Indicates the upper-layer protocol that is used in the data portion of an IPv4 packet. For example, a protocol value of 6 indicates this packet carries a TCP segment.
Protocol
Used for header error detection
Header Checksum
Includes optional parameters
Options
Used to ensure that the header ends on a 32-bit boundary
Padding
A Class A address block is designed to support extremely large networks with more than 16 million host addresses. The Class A address uses only the first octet (8 bits) of the 32-bit number to indicate the network address.
Class A
The Class B address space is designed to support the needs of moderate to large networks with more than 65,000 hosts. The Class B address uses two of the four octets (16 bits) to indicate the network address.
Class B
The Class C address space is the most commonly available address class. This address space is intended to provide addresses for small networks with a maximum of 254 hosts. In a Class C address, the first three octets (24 bits) of the address identify the network portion, with the remaining octet reserved for the host portion.
Class
Class D (multicast) IPv4 addresses are dedicated to multicast applications such as streaming media. Multicasts are a special type of broadcast, in that only hosts that request to participate in the multicast group will receive the traffic to the IPv4 address of that group.
Class D
Class E (reserved) IPv4 addresses are reserved by the IANA as a block of experimental addresses. Class E IPv4 addresses should never be assigned to IPv4 hosts. A Class E address begins with binary 1111.
Class E
Because the network is not segmented, you can not apply security policies adapted to individual segments. If one device is compromised, it can quickly affect the whole network.
Security
Isolation of network faults is more challenging especially in bigger flat networks, because there is no logical separation or hierarchy.
Troubleshooting
In a large flat network you can end up with a lot of wasted IP addresses. You cannot use addresses from this network anywhere else.
Address space utilization
A flat network represents a single Layer 2 broadcast domain. If there is a large amount of broadcast traffic this can impose a considerable pressure on the available resources. A single broadcast domain typically should not include more than a couple of hundred devices.
Scalability and speed
The network address is a standard way to refer to a network. An IPv4 address that has binary zeros in all the host bit positions is reserved for the network address.
Network Address
