-------1. Physical Network Layer
Receives the packet in its frame form. It computes the CRC of the packet and then sends the frame to the data link layer.
------2. Data-Link Layer
Verifies that the CRC for the frame is correct and strips off the frame header and CRC. Finally, the data link protocol sends the frame to the Internet layer.
------3. Internet Layer
Reads information in the header to identify the transmission and determine if it is a fragment. If the transmission was fragmented, IP reassembles the
fragments into the original datagram. It then strips off the IP header and passes the datagram on to transport layer protocols
------4. Transport Layer (TCP and UDP)
Reads the header to determine which application layer protocol must receive the data. Then TCP or UDP strips off its related header and sends the message or stream up to the receiving application.
-----5. Application Layer
Receives the message and performs the operation requested by the sending host.
---------Planning Your Network
This chapter describes the issues you must resolve in order to create your network in an organized, cost-effective manner. When you have resolved these issues, you can devise a plan for your network to follow as you set it up and administer it in the future.
Network Administrator:
Responsibilities of the Network Administrator
As a network administrator, your tasks generally will fall into four areas:
• Designing and planning the network -chap 3
• Setting up the network -chap 4
• Maintaining the network -chap 6
• Expanding the network
-------Expanding the Network
Several options are available for expanding your network:
• Setting up a new network and connecting it to the existing network using a
machine functioning as a router, thus creating an internetwork.
• Configuring machines in users’ homes or in remote office sites and enabling
these machines to connect over telephone lines to your network.
• Connecting your network to the Internet, thus enabling users on your
network to retrieve information from other systems throughout the world.
• Configuring UUCP communications, enabling users to exchange files and
electronic mail with remote machines.
----------What TCP/IP Is
Friday, April 16, 2010
TERMINOLOGIES IN NETWORKING
ICMP Protocol
Internet Control Message Protocol (ICMP) is the protocol responsible for
detecting network error conditions and reporting on them. ICMP reports on
• Dropped packets (when packets are arriving too fast to be processed)
• Connectivity failure (when a destination host can’t be reached)
• Redirection (which tells a sending host to use another router)
----------LIST OF PROTOCOLS
(SMTP)-simple mail transfer protocol
SNMP - The Simple Network Management Protocol
TFTP - The trivial file transfer protocol
(RIP) - The Routing Information Protocol
Telnet - The Telnet protocol
FTP - The File Transfer Protocol (FTP)
(UDP) - User Datagram Protocol
(ICMP) - Internet Control Message Protocol
(ARP) - The Address Resolution Protocol
(IP) - Internet protocol
(PPP) - Point-to-Point Protocol
(SNMP) - The Simple Network Management Protocol
RDISC - Router Discovery Protocol
UDP is a “connectionless” protocol.
(PAP) - Password Authentication Protocol
(CHAP) - Challenge Handshake Authentication Protocol
(IAB) - Internet Architecture Board
(FYI) - For Your Information
(RFCs) - Requests for Comments
(EIGRP) - Enhanced Interior Gateway Routing Protocol
InterNIC - (Internet Network Information Center)
Internet Control Message Protocol (ICMP) is the protocol responsible for
detecting network error conditions and reporting on them. ICMP reports on
• Dropped packets (when packets are arriving too fast to be processed)
• Connectivity failure (when a destination host can’t be reached)
• Redirection (which tells a sending host to use another router)
----------LIST OF PROTOCOLS
(SMTP)-simple mail transfer protocol
SNMP - The Simple Network Management Protocol
TFTP - The trivial file transfer protocol
(RIP) - The Routing Information Protocol
Telnet - The Telnet protocol
FTP - The File Transfer Protocol (FTP)
(UDP) - User Datagram Protocol
(ICMP) - Internet Control Message Protocol
(ARP) - The Address Resolution Protocol
(IP) - Internet protocol
(PPP) - Point-to-Point Protocol
(SNMP) - The Simple Network Management Protocol
RDISC - Router Discovery Protocol
UDP is a “connectionless” protocol.
(PAP) - Password Authentication Protocol
(CHAP) - Challenge Handshake Authentication Protocol
(IAB) - Internet Architecture Board
(FYI) - For Your Information
(RFCs) - Requests for Comments
(EIGRP) - Enhanced Interior Gateway Routing Protocol
InterNIC - (Internet Network Information Center)
Part 3
Host Name
The host name is the name of the local machine, combined with the name of
your organization. Many organizations let users choose the host names for
their machines. Programs such assendmail andrlogin use host names to specify remote machines on a network. System Administration Guide, Volume I
contains more information about host names.
IP Address
The IP address is one of the two types of addresses each machine has on a TCP/IP network that identifies the machine to its peers on the network. This address also gives peer hosts a notion of where a particular host is located on the network. If you have installed the Solaris operating environment on a machine on a network, you may recall specifying the IP address during the
installation process. IP addressing is a significant aspect of TCP/IP and is explained fully in ”Designing Your IP Addressing Scheme” on page 33.
Hardware Address
Each host on a network has a hardware address, which also identifies it to its peers. This address is physically assigned to the machine’s CPU or network interface by the manufacturer. Each hardware address is unique.
Reaching Beyond the Local-Area Network—the Wide-Area Network
As your network continues to function successfully, users may need to access information available from other companies, institutes of higher learning, and
other organizations not on your LAN. To obtain this information, they may need to communicate over a wide-area network (WAN), a network that covers a
potentially vast geographic area and uses network media such as leased data or telephone lines, X.25, and ISDN services.
A prime example of a WAN is the Internet, the global public network that is the successor to the WANs for which TCP/IP was originally developed. Other examples of WANs are enterprise networks, linking the separate offices of a single corporation into one network spanning an entire country, or perhaps an entire continent. It is entirely possible for your organization to construct its own WAN.
To interconnect your TCP/IP network with other networks, you must obtain a unique IP network number. At the time of this writing, IP network numbers
are assigned by an organization known as the InterNIC.
If hosts on your network are going to participate in the Internet Domain Name system (DNS), you must obtain and register a unique domain name. The InterNIC also handles the registration of domain names under certain top-level domains such as .com (commercial), .edu (education), and .gov (government).
Chapter 3, “Planning Your Network,” contains more information about the InterNIC. (For more information on DNS, refer to NIS+ and FNS Administration Guide.)
The host name is the name of the local machine, combined with the name of
your organization. Many organizations let users choose the host names for
their machines. Programs such assendmail andrlogin use host names to specify remote machines on a network. System Administration Guide, Volume I
contains more information about host names.
IP Address
The IP address is one of the two types of addresses each machine has on a TCP/IP network that identifies the machine to its peers on the network. This address also gives peer hosts a notion of where a particular host is located on the network. If you have installed the Solaris operating environment on a machine on a network, you may recall specifying the IP address during the
installation process. IP addressing is a significant aspect of TCP/IP and is explained fully in ”Designing Your IP Addressing Scheme” on page 33.
Hardware Address
Each host on a network has a hardware address, which also identifies it to its peers. This address is physically assigned to the machine’s CPU or network interface by the manufacturer. Each hardware address is unique.
Reaching Beyond the Local-Area Network—the Wide-Area Network
As your network continues to function successfully, users may need to access information available from other companies, institutes of higher learning, and
other organizations not on your LAN. To obtain this information, they may need to communicate over a wide-area network (WAN), a network that covers a
potentially vast geographic area and uses network media such as leased data or telephone lines, X.25, and ISDN services.
A prime example of a WAN is the Internet, the global public network that is the successor to the WANs for which TCP/IP was originally developed. Other examples of WANs are enterprise networks, linking the separate offices of a single corporation into one network spanning an entire country, or perhaps an entire continent. It is entirely possible for your organization to construct its own WAN.
To interconnect your TCP/IP network with other networks, you must obtain a unique IP network number. At the time of this writing, IP network numbers
are assigned by an organization known as the InterNIC.
If hosts on your network are going to participate in the Internet Domain Name system (DNS), you must obtain and register a unique domain name. The InterNIC also handles the registration of domain names under certain top-level domains such as .com (commercial), .edu (education), and .gov (government).
Chapter 3, “Planning Your Network,” contains more information about the InterNIC. (For more information on DNS, refer to NIS+ and FNS Administration Guide.)
NETWORKING ENGINEERING Part 2
------Computers and Their Connectors
Computers on a TCP/IP network use two different kinds of connectors to
connect to network media: serial ports, and the ports on the network interface.
---Serial Ports
Each computer has at least two serial ports, the connectors that enable you to
plug a printer or modem into the computer. The serial ports may be attached to
the CPU board, or you may have to purchase them. You use these ports when
attaching a modem to the system to establish a PPP or UUCP connection. PPP
and UUCP actually provide wide-area network services, since they may use
telephone lines as their network media.
---Network Interfaces
The hardware in a computer that enables you to connect it to a network is
known as a network interface. Many computers come with a preinstalled
network interface; others may require you to purchase the network interface
separately.
Computers on a TCP/IP network use two different kinds of connectors to
connect to network media: serial ports, and the ports on the network interface.
---Serial Ports
Each computer has at least two serial ports, the connectors that enable you to
plug a printer or modem into the computer. The serial ports may be attached to
the CPU board, or you may have to purchase them. You use these ports when
attaching a modem to the system to establish a PPP or UUCP connection. PPP
and UUCP actually provide wide-area network services, since they may use
telephone lines as their network media.
---Network Interfaces
The hardware in a computer that enables you to connect it to a network is
known as a network interface. Many computers come with a preinstalled
network interface; others may require you to purchase the network interface
separately.
NETWORKING ENGINEERING
What TCP/IP is?
A network communications protocol is a set of formal rules that describe how
software and hardware should interact within a network. For the network to
function properly, information must be delivered to the intended destination
in an intelligible form. Because different types of networking software and
hardware need to interact to perform the network function, designers
developed the concept of the communications protocol.
TCP/IP is
recognized as a standard by major international standards organizations and is
used throughout the world. Because it is a set of standards, TCP/IP runs on
many different types of computers, making it easy for you to set up a
heterogeneous network running the Solaris operating system.
TCP/IP provides services to many different types of computers, operating
systems, and networks. Types of networks range from local area networks,
such as Ethernet, FDDI, and Token Ring, to wide-area networks, such as T1
(telephone lines), X.25, and ATM.
You can use TCP/IP to construct a network out of a number local-area
networks. You can also use TCP/IP to construct a wide-area network by way
of virtually any point-to-point digital circuit
TCP/IP is the commonly used nickname for the set of network protocols
composing the Internet Protocol suite. Many texts use the term “Internet” to
describe both the protocol suite and the global wide-area network. In this
book, the “TCP/IP” refers specifically to the Internet protocol suite; “Internet”
refers to the wide-area network and the bodies that govern it.
------The term local-area network (LAN) refers to a single network of computers
limited to a moderate geographical range, such as the floor of a building or
two adjacent buildings. A local-area network has both hardware and software
components.
-----Local-Area Network Media
The cabling or wiring used for computer networks is referred to as network
media.
In the Solaris LAN environment, Ethernet is the most commonly used
local-area network media. Other types of local-area network media used in a
Solaris LAN might include FDDI or Token Ring.
A network communications protocol is a set of formal rules that describe how
software and hardware should interact within a network. For the network to
function properly, information must be delivered to the intended destination
in an intelligible form. Because different types of networking software and
hardware need to interact to perform the network function, designers
developed the concept of the communications protocol.
TCP/IP is
recognized as a standard by major international standards organizations and is
used throughout the world. Because it is a set of standards, TCP/IP runs on
many different types of computers, making it easy for you to set up a
heterogeneous network running the Solaris operating system.
TCP/IP provides services to many different types of computers, operating
systems, and networks. Types of networks range from local area networks,
such as Ethernet, FDDI, and Token Ring, to wide-area networks, such as T1
(telephone lines), X.25, and ATM.
You can use TCP/IP to construct a network out of a number local-area
networks. You can also use TCP/IP to construct a wide-area network by way
of virtually any point-to-point digital circuit
TCP/IP is the commonly used nickname for the set of network protocols
composing the Internet Protocol suite. Many texts use the term “Internet” to
describe both the protocol suite and the global wide-area network. In this
book, the “TCP/IP” refers specifically to the Internet protocol suite; “Internet”
refers to the wide-area network and the bodies that govern it.
------The term local-area network (LAN) refers to a single network of computers
limited to a moderate geographical range, such as the floor of a building or
two adjacent buildings. A local-area network has both hardware and software
components.
-----Local-Area Network Media
The cabling or wiring used for computer networks is referred to as network
media.
In the Solaris LAN environment, Ethernet is the most commonly used
local-area network media. Other types of local-area network media used in a
Solaris LAN might include FDDI or Token Ring.
SOLAR WATER HEATERS (PART 2)
Solving these problems can often be done automatically and you can configure these solutions in the form of a task. This can be something as simple as informing the administrator or reloading a service or running a query. However, there are also more complex actions that can be carried out by using customized scripts in languages such as Visual Basic, Active Perl, Active Python or JavaScript. However, in cases where a problem simply cannot be solved automatically, the administrator can instead be warned of the issue by various different methods. This can include sending an SMS, e-mail or other instant message directly to the network administrator.
Wizards are another automation feature of the software. It is designed to configure various checks of multiple elements over the network, organizing these checks in groups so that they may be carried out in a timely manner. There are a virtually unlimited number of different checks that can be carried. These can include pinging network devices, scanning ports or monitoring usage of resources such as disk space and memory. Database status may also be checked as well as the monitoring of network printers, network addresses and even checking for content published on a website.
Real-time filter groups are supported, meaning that special folders can be used to view and access particular tasks defined by specified conditions. This allows for real-time monitoring. HTML report generation is available, generating reports both on demand and by the schedule.
To find out more about this advanced network performance monitor, pay a visit to http://monitor.extromatica.com/. You can download a trial edition. The full package comes in either the standard or professional version. You can start benefiting right away from the amount of time that this software will free up for you. All licensing schemes allow for management of an unlimited number of network elements so you do not need to worry about getting a new license if your network expands in the future.
Kudos to the researcher.
Wizards are another automation feature of the software. It is designed to configure various checks of multiple elements over the network, organizing these checks in groups so that they may be carried out in a timely manner. There are a virtually unlimited number of different checks that can be carried. These can include pinging network devices, scanning ports or monitoring usage of resources such as disk space and memory. Database status may also be checked as well as the monitoring of network printers, network addresses and even checking for content published on a website.
Real-time filter groups are supported, meaning that special folders can be used to view and access particular tasks defined by specified conditions. This allows for real-time monitoring. HTML report generation is available, generating reports both on demand and by the schedule.
To find out more about this advanced network performance monitor, pay a visit to http://monitor.extromatica.com/. You can download a trial edition. The full package comes in either the standard or professional version. You can start benefiting right away from the amount of time that this software will free up for you. All licensing schemes allow for management of an unlimited number of network elements so you do not need to worry about getting a new license if your network expands in the future.
Kudos to the researcher.
SOLAR WATER HEATERS (PART 1)
The popularity enjoyed by passive solar water heaters is much bigger than you might imagine. The problem is that a lot of people do not actually know what they are. You might be faced with noticing one big tank inside a house and not being aware of its main purpose of being a good passive heating system. So how can we define a passive solar heating system?
Passive solar technologies stand out as ways in which you use sunlight to gain energy without the extra addition of mechanical systems. This is in contrast with the use of active solar technologies. This is one type of technology that is really useful in converting sun energy into heat in order to be used for heating purposes. One really interesting fact is that you will not need extra energy sources and if they are needed only minimal use is required. One good example that we can mention is solariums built on southern sides of buildings. Alternatively passive cooling can also be utilized and all is based on the same principles but with opposed goals. It is used to reduce cooling requirements during summer.
Do not make the mistake of thinking that a passive solar water heater system is actually an active system. One highly simple fact stands around conventional energy use. If it is used to power pumps or fans then we do have one active system. Different passive system will also utilize conventional energy but only a small amount of it.
Passive water heater technologies based on solar power will include both direct and indirect solar gains for space heating purposes. Heating systems are usually based on the use of thermal mass, thermosiphon or even phase-change materials. In wider spreads technology that is used in passive solar systems also include solar furnaces or solar forges. These systems are to need extra energy sources so that receiver alignment andmirror concentration can be achieved. We have noticed them to be ineffective in a wide spread use. The proper way for you to implement any passive solar system is by using low grade energy needs.
Extromatica Network Performance Monitor is your one-stop solution for monitoring your network's performance and making sure that efficiency is always kept to a maximum. The checks that can be carried out by this software cover the widest range of hardware and software, including elements that use different monitoring approaches like printers, servers, databases, services and websites. All of these can be closely monitored in order to ensure the highest degree of performance. Any faults or drops in performance will be automatically logged and stored in the software's event log. Solutions to problems may also be automatically applied or the network administrator may choose to take over following a notification from the software.
Faults can mean different things depending on the network elements that they are relevant to. Problems can be things such as an important service no longer working, a storage device that is almost full or simply a website that is no longer responding. Reduced performance and reduced bandwidth can also occur in addition to slow response time of your devices and other network elements.
Passive solar technologies stand out as ways in which you use sunlight to gain energy without the extra addition of mechanical systems. This is in contrast with the use of active solar technologies. This is one type of technology that is really useful in converting sun energy into heat in order to be used for heating purposes. One really interesting fact is that you will not need extra energy sources and if they are needed only minimal use is required. One good example that we can mention is solariums built on southern sides of buildings. Alternatively passive cooling can also be utilized and all is based on the same principles but with opposed goals. It is used to reduce cooling requirements during summer.
Do not make the mistake of thinking that a passive solar water heater system is actually an active system. One highly simple fact stands around conventional energy use. If it is used to power pumps or fans then we do have one active system. Different passive system will also utilize conventional energy but only a small amount of it.
Passive water heater technologies based on solar power will include both direct and indirect solar gains for space heating purposes. Heating systems are usually based on the use of thermal mass, thermosiphon or even phase-change materials. In wider spreads technology that is used in passive solar systems also include solar furnaces or solar forges. These systems are to need extra energy sources so that receiver alignment andmirror concentration can be achieved. We have noticed them to be ineffective in a wide spread use. The proper way for you to implement any passive solar system is by using low grade energy needs.
Extromatica Network Performance Monitor is your one-stop solution for monitoring your network's performance and making sure that efficiency is always kept to a maximum. The checks that can be carried out by this software cover the widest range of hardware and software, including elements that use different monitoring approaches like printers, servers, databases, services and websites. All of these can be closely monitored in order to ensure the highest degree of performance. Any faults or drops in performance will be automatically logged and stored in the software's event log. Solutions to problems may also be automatically applied or the network administrator may choose to take over following a notification from the software.
Faults can mean different things depending on the network elements that they are relevant to. Problems can be things such as an important service no longer working, a storage device that is almost full or simply a website that is no longer responding. Reduced performance and reduced bandwidth can also occur in addition to slow response time of your devices and other network elements.
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