Defination: Answer them all if cant, dont bother to look ANDing Private address

Question

Defination:

Answer them all if cant, dont bother to look

ANDing

Private address ranges

IPv6 link local address range

Ping vs. tracert

Subnetting (big one)

# of networks, # of hosts

VLSM (concept and process)

TCP vs. UDP

Windowing (also called sliding window)

Protocols (know what they are, port#, & which layer)

Peer-to-peer operation

HTTP messages

Network packet captures

Device security commands

Logical vs physical topology

Media types

Parts of routing table and how it functions

ANDing

Private address ranges

IPv6 link local address range

Ping vs. tracert

Subnetting (big one)

# of networks, # of hosts

VLSM (concept and process)

TCP vs. UDP

Windowing (also called sliding window)

Protocols (know what they are, port#, & which layer)

Peer-to-peer operation

HTTP messages

Network packet captures

Device security commands

Logical vs physical topology

Media types

Parts of routing table and how it functions

Explanation / Answer

Answer:

Anding:

When a source host attempts to communicate with a destination host, the source host uses its subnet mask to determine whether the destination host is on the local network or a remote network. This is known as the ANDing process.

The AND function has the following properties:

· If the two compared values are both 1, the result is 1.

· If one of the values is 0 and the other is 1, the result is 0.

· If both of the compared values are 0, the result is 0.

Private address ranges:

A:10.0.0.0 to 10.255.255.255

B:172.16.0.0 to 172.31.255.255

C:192.168.0.0 to 192.168.255.255

Private address ranges:

In the Internet Protocol Version 6 (IPv6), the address block fe80::/64 has been reserved for link-local unicast addressing. Of the 64 bits of a link-local addresses' network component, the most significant 10 bits (1111111010) correspond to the IANA-reserved "global routing prefix" for link-local addresses, while the "subnet ID" (the remaining 54 bits) is zero.

Ping vs. tracert:

Ping

Ping (also written as PING or ping) is a utility that you use to determine whether or not a specific IP address is accessible. Ping works by sending a packet to a specified address and waiting for a reply. Ping is used primarily to troubleshoot Internet connections and there are many freeware and shareware Ping utilities available for download.

On a Windows PC you can run Ping using a command prompt. To do this, go to the Windows Start button, choose Programs, then MSDOS Prompt. When you get the C: prompt, type ping followed by the destination server name or an IP address, for example, ping google.com

Traceroute

Traceroute is a utility that traces a packet from your computer to an Internet host, but it will show you how many hops the packet requires to reach the host and how long each hop takes. If you're visiting a Web site and pages are appearing slowly, you can use traceroute to figure out where the longest delays are occurring. Traceroute utilities work by sending packets with low time-to-live (TTL) fields. The TTL value specifies how many hops the packet is allowed before it is returned. When a packet can't reach its destination because the TTL value is too low, the last host returns the packet and identifies itself. By sending a series of packets and incrementing the TTL value with each successive packet, traceroute finds out who all the intermediary hosts are.

The original traceroute is a UNIX utility, but nearly all platforms have something similar. Windows includes a traceroute utility called tracert. On a Windows PC you can run traceroute using a command prompt To do this, go to the Windows Start button, choose Programs, then MSDOS Prompt. When you get the C: prompt, type tracert followed by the destination server name or an IP address, for example: tracert google.com

Subnetting:

Subnetting is the strategy used to partition a single physical network into more than one smaller logical sub-networks (subnets). An IP address includes a network segment and a host segment. Subnets are designed by accepting bits from the IP address's host part and using these bits to assign a number of smaller sub-networks inside the original network. Subnetting allows an organization to add sub-networks without the need to acquire a new network number via the Internet service provider (ISP). Subnetting helps to reduce the network traffic and conceals network complexity. Subnetting is essential when a single network number has to be allocated over numerous segments of a local area network (LAN).

Subnets were initially designed for solving the shortage of IP addresses over the Internet.

Each IP address consists of a subnet mask. All the class types, such as Class A, Class B and Class C include the subnet mask known as the default subnet mask. The subnet mask is intended for determining the type and number of IP addresses required for a given local network. The firewall or router is called the default gateway. The default subnet mask is as follows:

The subnetting process allows the administrator to divide a single Class A, Class B, or Class C network number into smaller portions. The subnets can be subnetted again into sub-subnets.

Dividing the network into a number of subnets provides the following benefits:

VLSM:

Variable-Length Subnet Masking (VLSM) amounts to "subnetting subnets," which means that VLSM allows network engineers to divide an IP address space into a hierarchy of subnets of different sizes, making it possible to create subnets with very different host counts without wasting large numbers of addresses.

A subnet mask defines the size of the subnet (the number of host addresses in the subnet). Fixed-Length Subnet Masking (FLSM) creates subnets all the same size. But where some subnets will have many hosts and some have few, FLSM results in some subnets having many orphaned addresses, or some sets of hosts being too big to fit into a subnet. Where VLSM is enabled, a large subnet can be divided into a set of smaller sub-subnets, which can be used to handle smaller sets of hosts.

For example, consider a traditional Class C address space like 192.168.1.0 and an organization with four groups of computers: the data center with 75 hosts; the call center with 50; the operations floor with 25; and the executive floor with 20. Under fixed subnetting, dividing the 255 host addresses available into four subnets would support only 62 hosts each, not meeting the needs of the data center and vastly oversupplying addresses for operations and the execs. Using VLSM, the space is first split in 2, with each subnet able to address 126 hosts. One subnet covers the data center. The other is split in two, supplying two sub-subnets of 62 hosts. One covers the contact center, the other is split in two once more, creating two 30-host sub-sub-subnets, to cover operations and executives.

In order to use VLSM, a network administrator must use a routing protocol that supports it, such as Routing Information Protocol v2 (RIPv2), Open Shortest Path First (OSPF), Intermediate System-to-Intermediate System (IS-IS), Enhanced Interior Gateway Routing Protocol (EIGRP) and Border Gateway Protocol (BGP).

TCP vs. UDP:

TCP:

->Transmission Control Protocol

->It is a connection oriented protocol

->TCP is used in case of applications in which fast transmission of data is not required

->HTTP, FTP, SMTP Telnet etc

->It rearranges data packets in the order specified

->TCP header size is 20 bytes

->Data is read as a byte stream, thus no distinguishing indications are transmitted to the signal message

->It is heavier as it requires three packets to set up a socket connection, before any user data can be sent. TCP handles reliability and congestion control

->TCP controls the flow of data

UDP:

->User Datagram Protocol or Universal Datagram Protocol

->It is a connection less protocol

->UDP is preferred in case of the applications which have the priority of sending the data on time and on faster rates

->DNS, DHCP, TFTP, SNMP, RIP, VOIP etc

->No inherent ordering, the data packets of same message may be ordered differently

->Packets are sent individually and after the arrival the packets are rearranged

->UDP is lightweight due to no ordering of messages, no tracking connections, etc.

->UDP does not have an option for flow control.

windowing:

Sliding windows, a technique also known as windowing, is used by the Internet's Transmission Control Protocol (TCP) as a method of controlling the flow of packets between two computers or network hosts. ... Sliding windows is a method by which multiple packets of data can be affirmed with a single acknowledgment.

Protocols:

File Transfer Protocol (FTP)

(RFC 959)`

Secure Shell (SSH)

(RFC 4250-4256)

Telnet

(RFC 854)

Simple Mail Transfer Protocol (SMTP)

(RFC 5321)

Domain Name System (DNS)

(RFC 1034-1035)

Dynamic Host Configuration Protocol (DHCP)

(RFC 2131)

Trivial File Transfer Protocol (TFTP)

(RFC 1350)

Hypertext Transfer Protocol (HTTP)

(RFC 2616)

Post Office Protocol (POP) version 3

(RFC 1939)

Network Time Protocol (NTP)

(RFC 5905)

NetBIOS

(RFC 1001-1002)

Internet Message Access Protocol (IMAP)

(RFC 3501)

Simple Network Management Protocol (SNMP)

(RFC 1901-1908, 3411-3418)

Border Gateway Protocol (BGP)

(RFC 4271)

Lightweight Directory Access Protocol (LDAP)

(RFC 4510)

Hypertext Transfer Protocol over SSL/TLS (HTTPS)

(RFC 2818)

Lightweight Directory Access Protocol over TLS/SSL (LDAPS)

(RFC 4513)

FTP over TLS/SSL

(RFC 4217

Peer-to-peer operation:

Peer-to-peer (P2P) is a decentralized communications model in which each party has the same capabilities and either party can initiate a communication session. Unlike the client/server model, in which the client makes a service request and the server fulfills the request, the P2P network model allows each node to function as both a client and server.

P2P systems can be used to provide anonymized routing of network traffic, massive parallel computing environments, distributed storage and other functions. Most P2P programs are focused on media sharing and P2P is therefore often associated with software piracy  and copyright violation.

Typically, peer-to-peer applications allow users to control many parameters of operation: how many member connections to seek or allow at one time; whose systems to connect to or avoid; what services to offer; and how many system resources to devote to the network. Some simply connect to some subset of active nodes in the network with little user control, however.

HTTP messages:

HTTP messages are how data is exchanged between a server and a client. There are two types of messages:requests sent by the client to trigger an action on the server, and responses, the answer from the server. HTTP messages are composed of textual information encoded in ASCII, and span over multiple lines.

Network packet captures:

Packet capture is a computer networking term for intercepting a data packet that is crossing or moving over a specific computer network.

Once a packet is captured, it is stored temporarily so that it can be analyzed. The packet is inspected to help diagnose and solve network problems and determine whether network security policies are being followed.

Hackers can also use packet capturing techniques to steal data that is being transmitted over a network.

Logical vs physical topology:

A logical topology is how devices appear connected to the user. A physical topology is how they are actually interconnected with wires and cables. For example, in a shared Ethernet network that uses hubs rather than switches, the logical topology appears as if every node is connected to a common bus that runs from node to node. However, its physical topology is a star, in which every node on the network connects to a central hub. See Ethernet and logical vs. physical.
->

Media types:

Network media is the actual path over which an electrical signal travels as it moves from one component to another. This chapter describes the common types of network media, including twisted-pair cable, coaxial cable, fiber-optic cable, and wireless.

Twisted-Pair Cable

Twisted-pair cable is a type of cabling that is used for telephone communications and most modern Ethernet networks. A pair of wires forms a circuit that can transmit data. The pairs are twisted to provide protection against crosstalk, the noise generated by adjacent pairs. When electrical current flows through a wire, it creates a small, circular magnetic field around the wire. When two wires in an electrical circuit are placed close together, their magnetic fields are the exact opposite of each other. Thus, the two magnetic fields cancel each other out. They also cancel out any outside magnetic fields. Twisting the wires can enhance this cancellation effect. Using cancellation together with twisting the wires, cable designers can effectively provide self-shielding for wire pairs within the network media.

Two basic types of twisted-pair cable exist: unshielded twisted pair (UTP) and shielded twisted pair (STP). The following sections discuss UTP and STP cable in more detail.

UTP Cable:

UTP cable is a medium that is composed of pairs of wires (see Figure 8-1). UTP cable is used in a variety of networks. Each of the eight individual copper wires in UTP cable is covered by an insulating material. In addition, the wires in each pair are twisted around each other.

hielded Twisted-Pair Cable

Shielded twisted-pair (STP) cable combines the techniques of shielding, cancellation, and wire twisting. Each pair of wires is wrapped in a metallic foil . The four pairs of wires then are wrapped in an overall metallic braid or foil, usually 150-ohm cable. As specified for use in Ethernet network installations, STP reduces electrical noise both within the cable (pair-to-pair coupling, or crosstalk) and from outside the cable (EMI and RFI). STP usually is installed with STP data connector, which is created especially for the STP cable. However, STP cabling also can use the same RJ connectors that UTP uses.

Protocol Port Number Description

File Transfer Protocol (FTP)

(RFC 959)`

20/21 FTP is one of the most commonly used file transfer protocols on the Internet and within private networks. An FTP server can easily be set up with little networking knowledge and provides the ability to easily relocate files from one system to another. FTP control is handled on TCP port 21 and its data transfer can use TCP port 20 as well as dynamic ports depending on the specific configuration.

Secure Shell (SSH)

(RFC 4250-4256)

22 SSH is the primary method used to manage network devices securely at the command level. It is typically used as a secure alternative to Telnet which does not support secure connections.

Telnet

(RFC 854)

23 Telnet is the primary method used to manage network devices at the command level. Unlike SSH which provides a secure connection, Telnet does not, it simply provides a basic unsecured connection. Many lower level network devices support Telnet and not SSH as it required some additional processing. Caution should be used when connecting to a device using Telnet over a public network as the login credentials will be transmitted in the clear.

Simple Mail Transfer Protocol (SMTP)

(RFC 5321)

25 SMTP is used for two primary functions, it is used to transfer mail (email) from source to destination between mail servers and it is used by end users to send email to a mail system.

Domain Name System (DNS)

(RFC 1034-1035)

53 The DNS is used widely on the public internet and on private networks to translate domain names into IP addresses, typically for network routing. DNS is hieratical with main root servers that contain databases that list the managers of high level Top Level Domains (TLD) (such as .com). These different TLD managers then contain information for the second level domains that are typically used by individual users (for example, cisco.com). A DNS server can also be set up within a private network to private naming services between the hosts of the internal network without being part of the global system.

Dynamic Host Configuration Protocol (DHCP)

(RFC 2131)

67/68 DHCP is used on networks that do not use static IP address assignment (almost all of them). A DHCP server can be set up by an administrator or engineer with a poll of addresses that are available for assignment. When a client device is turned on it can request an IP address from the local DHCP server, if there is an available address in the pool it can be assigned to the device. This assignment is not permanent and expires at a configurable interval; if an address renewal is not requested and the lease expires the address will be put back into the poll for assignment.

Trivial File Transfer Protocol (TFTP)

(RFC 1350)

69 TFTP offers a method of file transfer without the session establishment requirements that FTP uses. Because TFTP uses UDP instead of TCP it has no way of ensuring the file has been properly transferred, the end device must be able to check the file to ensure proper transfer. TFTP is typically used by devices to upgrade software and firmware; this includes Cisco and other network vendors’ equipment.

Hypertext Transfer Protocol (HTTP)

(RFC 2616)

80 HTTP is one of the most commonly used protocols on most networks. HTTP is the main protocol that is used by web browsers and is thus used by any client that uses files located on these servers

Post Office Protocol (POP) version 3

(RFC 1939)

110 POP version 3 is one of the two main protocols used to retrieve mail from a server. POP was designed to be very simple by allowing a client to retrieve the complete contents of a server mailbox and then deleting the contents from the server.

Network Time Protocol (NTP)

(RFC 5905)

123 One of the most overlooked protocols is NTP. NTP is used to synchronize the devices on the Internet. Even most modern operating systems support NTP as a basis for keeping an accurate clock. The use of NTP is vital on networking systems as it provides an ability to easily interrelate troubles from one device to another as the clocks are precisely accurate.

NetBIOS

(RFC 1001-1002)

137/138/139 NetBIOS itself is not a protocol but is typically used in combination with IP with the NetBIOS over TCP/IP (NBT) protocol. NBT has long been the central protocol used to interconnect Microsoft Windows machines.

Internet Message Access Protocol (IMAP)

(RFC 3501)

143 IMAP version3 is the second of the main protocols used to retrieve mail from a server. While POP has wider support, IMAP supports a wider array of remote mailbox operations which can be helpful to users.

Simple Network Management Protocol (SNMP)

(RFC 1901-1908, 3411-3418)

161/162 SNMP is used by network administrators as a method of network management. SNMP has a number of different abilities including the ability to monitor, configure and control network devices. SNMP traps can also be configured on network devices to notify a central server when specific actions are occurring. Typically, these are configured to be used when an alerting condition is happening. In this situation, the device will send a trap to network management stating that an event has occurred and that the device should be looked at further for a source to the event.

Border Gateway Protocol (BGP)

(RFC 4271)

179 BGP version 4 is widely used on the public internet and by Internet Service Providers (ISP) to maintain very large routing tables and traffic processing. BGP is one of the few protocols that have been designed to deal with the astronomically large routing tables that must exist on the public Internet.

Lightweight Directory Access Protocol (LDAP)

(RFC 4510)

389 LDAP provides a mechanism of accessing and maintaining distributed directory information. LDAP is based on the ITU-T X.500 standard but has been simplified and altered to work over TCP/IP networks.

Hypertext Transfer Protocol over SSL/TLS (HTTPS)

(RFC 2818)

443 HTTPS is used in conjunction with HTTP to provide the same services but doing it using a secure connection which is provided by either SSL or TLS.

Lightweight Directory Access Protocol over TLS/SSL (LDAPS)

(RFC 4513)

636 Just like HTTPS, LDAPS provides the same function as LDAP but over a secure connection which is provided by either SSL or TLS.

FTP over TLS/SSL

(RFC 4217

989/990 Again, just like the previous two entries, FTP over TLS/SSL uses the FTP protocol which is then secured using either SSL or TLS.

Related Questions

Navigate

• Browse (All)
• Browse D
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.