Network and Broadcast Addresse

On a certain network the IP addresses are reserved and they cannot be assigned to whatever device we required. These addresses which are reserved are included in the network addresses, where it identifies the broadcast addresses and the network also, which helps to broadcast the data and the packets to the devices in the network.

Where in the IP addresses which have the binary 0s host positions is then reserved for the network address and therefore consider A class network which has 10.0.0.0 as a IP address in the network which contains the host as a 10.1.2.3. And then the router hosts the destination for the network location and consider B class network which had an IP address as 172.16.0.0 then it shows as
Network Address

In this the decimal numbers will fill the two octets in the first of a Class B are the address assigned and the last two octets which contain 0s because those 16 bits are of the hosts numbers are used to the devices which are connected to the network when consider the IP address 172.16.0.0 is which was registered in the network address and it will not use any address to the device which was attached to it and to that it can be explained as considering an example 172.16.0.0 and this will be 172.16.16.1 and in this IP address the 172.16 will be the network address portion and 16.1 will be address host portion.

Network Broadcast Address:

And if an existing IP address is connected to and device tend to communicate with other devices which are in the network it sets the destination address to all 1s (255.255.255.255) and there the transfer of information or data has been done. And this sort of the address can be used in the example by various hosts and which do not know their number of the network and it will ask the some other server for the number by the source of (RARP) Reverse Address Resolution Protocol or by the means of (DHCP) Dynamic Host Configuration Protocol. In this form of broadcasting the packets are never capable of the being routed, due to the RFC 1812 which prohibits the data to be forwarded in the whole networks broadcasting. And due to this issue all the networks broad casting are called as a local broadcast due to the stays in the LAN or VLAN segments

The network ID used to enables the router to put the packet to the network segment and then the host ID helps the router to deliver the layer 2 frame, which will encapsulate the packet data to a host on the network. Due to this the IP address is mapped to the exact MAC address which was required to the process for the layer 2 process in the system router and to its address frame.

Using Common Host Tools to Determine the IP Address of a Host

DNS addresses and host addresses cam be easily identified by the operating systems with the help of their series of tools.

According to the operating systems the settings are changed and in Microsoft Windows devices the network communication tab is setup under and enables to view the IP address configuration in the PC. From the DHCP server the PC is allowed to configure the address.

And to determine the address of the device and various IP configuration in the pc command prompt is used to run and in the IPCONFIG allows us to see all current TCP/IP network configuration values and used to refresh DHCP and DNS settings and various subnet mask are all displayed. The following shows the display type.

 The IPCONFIG can be run in various number of flags to known exactly what output is been displaying. And there syntax is shown below.

•    IPCONFIG [/all] :
o    It will displays all the full configurations of TCP/IP and its adapters. And in the absence of this sort of parameter, ipconfig shows only in the subnet mask, IP address and the default gateway values in each of the adapters. In these adapters are in represented in the sort of the physical address, known as logical adapters (dialup connections), or installed networks.

•    /renew [Adapter]:
o    It helps to renews the DHCP configurations for the all adaptors in case of not specification of the adaptors or for specialized adapter parameter if it is much included and this certain sort of parameters are available in the computers with have adapters that are configured in order to obtain the specified IP address automatically. And when the ipconfig without any sort of parameters there an adapter name should be specified.


•    /release [Adapter]:
o    In this adapter there sends a DHCPRELEASE message to the DHCP server in order to release the configuration the current DHCP and discard the other IP address configurations for a specific adapter if it was included. And then the TCP/IP disables by the parameter for IP configuration to be done automatically 


•    /flushdns:
o    In the DNS client resolver cache the content is flushes and resets. And on the process of the DNS troubleshooting, this sort of process is used to discard the negative and draw back entries into the cache and in the other hand other entries are added dynamically.


•    /displaydns:
o    The content of the DNS client resolver cache is displayed, and in these includes the entries which are preloaded from the obtained recent resource records and the local file hosts by the computer.


•    /registerdns:
o    The manual initiate of dynamic registration and the DNS names and various IP address are configured by the computer. And by using a parameter to trouble shoot the failed DNS name registration and problem can be resolve from the client computer without even rebooting the client’s computer. These sort of settings in the DNS are advanced properties for which TCP/IP protocol tends to determine which one is registered in the DNS.


•    /showclassid Adapter:
o    This adapter shows the class ID for the DHCP to a specified adaptor. And to see that we should use the asterisk (*) wildcard character in the place of an adaptor.


•    /setclassid Adapter [ClassID]:
o    This adapter configures the class ID for the DHCP to a specified adaptor. And to see that we should use the asterisk (*) wildcard character in the place of an adaptor. And in this if the class ID is not specified in the DHCP then current class ID is tend to be deleted.·     

Understanding TCP/IP’s Application and Transport Layers

When the data and certain communication is transferred among the networks and computers there obtain certain rules, and formats of receive and sending the data in a fashion mode. And around the globe the most commonly and widely used protocol suite is the IP/TCP. And knowing the work and important of TCP/IP plays a major role for the transfer of data transmission in the network environments.

It is a fundamental concept in the TCP/IP architecture of the way the IP delivers a packet of data through a network which was mostly used in the large networks. And to understand the TCP/IP suit of protocols in the function overall the IP is main central part.

The Transport Layer:

The transport is mainly resided in between the transport layer and the network layer which is layer 4 and it was mainly in the core of the TCP/IP of the network architecture. It has a very important critical role of providing the communication in between the hosts and the application process. And knowing the work and procedure of the transport layer means of knowing the data transmission in the TCP/IP network systems.

The data from the application is replaced by the transport layer by placing a header on it. And the main function of this protocol was to identify the application and to which the data is received and to the internet layer to be passed down to the certain segments. Two additional functions also be perform in the transport layer they are reliability (which are provided by the acknowledgements and numbers) and flow control (these are provided by sliding windows). Flow control is a sort of applications to which connects and enables the hosts to know the communicating mechanism and to count the data in which transmits each time. And other Reliability used to mechanism of the guarantee the packet to be delivered.

In the transport layer there are two type of protocols:

·        UDP: It is a protocol of unacknowledged and connectionless. And in these it is the responsible of transmitting the messages, and there are no certain checking for the segment delivery at this layer. It mainly depends upon the upper layer protocol for the reliability.

·        TCP: It is a reliable protocol, connection-oriented. A connection been oriented in between the two ends of the systems before the data is begin to transfer among them. TCP plays a major role in breaking of the signals and the messages into various sort of segments, and at destination centre they are used to reassemble them, and the data is resent to the host where they receive anything and the messages are reassembled. In between the end users applications TCP used to supply virtual circuit among them.

Two devices are connected there will be a communication among them and the data and messages are passed through them. And to understand and give response to this messages devices are acted on this messages they should agree and rely on the messages exchange and certain action was requires to respond the message.

Medium-Sized Switched Network Construction

Many factors must been addressed by the network administrators while a switched network is been expanding. And thus the cisco provides a solution for many immediate problems which are formed in the administrative changes and then they also provide interoperability, security, scalability, increased dedicated throughput.

Implementing VLANs and the Trunk:

Multiple LAN segments are span by the VLAN in a broadcasting domain. It is used in order to end the group stations they have a common set of requirements and to their independent of their certain physical locations. And in the VLAN they will be same sort of attributes same as like as a physical LAN, unless in one group end stations even LAN segment is not presented physically. Here the VLAN is used to group ports on a certain switch to limit the broadcast traffic flooding, unicast, and the multicast. And the traffic which was originated from the particular VLAN sort of floods and to the ports which are belonging to the VLAN.

      Understanding VLANs: Operation of the VLANs and its operation is associated with other types of protocols and there are important for the verifying, configuring and troubleshooting the VLANs in the Cisco access switches. And this sort of section describes the VLAN controls and their operations with their associated protocols. When a network was poorly designed and it leads to the increased costs of the supports, in the security risks, reduced service availability, and some of the limited support for another sort of applications and other solutions. The following are the issues which are raised in the stem for poorly designed network.
                         
    Broadcasting domains: In every network a broadcast is existed. And to function properly many type of network operations and applications are needed. And for that there is no possibility of elimination in a complete form. And in the same time on the other end avoiding the failures of the domains includes the clearly defining boundaries, and boundaries should and must have the clear domains and to reduce and minimize the impact of the broadcasts they should include an optimal number.

     Failure in Domains: a networks design is implemented for the one of the most important reason was to minimize the problems which occurred. And when there was not clearly defined layers 2 and layers 3 boundaries of the network, and one of the failure is resulted in the one of the network area which was far effected by far-reaching effect.

     Multicast traffic on the ports where it was not intended: Internet Protocol is a technique which was allowed in the IP traffic which is used to propagate from the source and to the multicast type of group which was identified and by a single IP address and the destination-group address pair of MAC. And to the similar unicast of the broadcasting and flooding, frames of the multicast are flooded out with all the switch type of ports.

     Difficulty Raised in support and the management: The network which was poorly designed and it results in the disorganization and poorly documented and in the lack of identification of the traffic flows, which will helps on the maintenance, support and in the arduous tasks and problem resolution time-consuming.

     And the Possible security vulnerabilities:  An entire network may be compromised in the access layer and certain requirements are been breached in a switched network.

And in a poorly designed network it may lead to the distraction and it have a negative impact and it becomes a burden infect of support to the certain organization.

Implementing VLANs and Trunks

Applying IP Address Space in the Enterprise Network:

A model framework is used for designing and deploying in the networks is provided by the Cisco enterprise architecture model. It also used to provide the overlaying hierarchical IP addressing scheme in the ideal structure in the addressing scheme there are some of the guidelines which are shown below:

• In the corresponding to a single VLAN of a single IP subnet. And in the each broadcast domain VLAN is a separate,

• At the certain building distribution layer, and then there will be a continuation in the assign network numbers in the contiguously to the access layer of the devices.

• Design the various IP addressing in the scheme of the various blocks in the 2ⁿ contiguous network of the numbers (such as the 4, 8, 16, 32, 64 and so on) to be assigned in the certain building access and the distribution of the switch block.

• Subnet is the same sort of the same binary values in all the networks of to avoid the variable-length in the subnet masks and when it’s possible.

Example: Network Design

 The following table shows the example of approximately 250 various employees are migrating into the Cisco Enterprise Architecture.

Departments’	Users In Numbers	Location
Accounting	26	Building C
Finance	18	Building C
Sales	102	Building B
Human Resources	10	Building A
IT	45	Building A
Marketing	29	Building B

Here there is a requirement for the Six VLANs in order to accommodate the one VLAN as per the user community. The guidelines for the following are the Cisco Enterprise Architecture, and they is a requirement of the six IP subnets.

And here the business took its base address as the 10.0.0.0 to use the network.

And for the future growth in the system and to accommodate it, there occurs the one block of an IP addresses in a building and these are shown as below.

• And the allocation of Building A is 10.1.0.0/16.
• And the allocation of Building B is 10.2.0.0/16.
• And the allocation of Building C is 10.3.0.0/16.

In the all sort of departments the sales department was the largest, and it requires of 102 addresses for the users. A subnet mask of around 255.255.255.0 (/24) was chosen and thus it provide a maximum number in subnet for 254 hosts

The following tables shows the allocation of the IP and VLANs subnets in the building of A, B and C.

In Building A: IP and the VLANs Subnets:

Department	VLAN	IP Subnet Address
IT	VLAN 11	10.1.1.0/24
Human Resources	VLAN 12	10.1.2.0/24
And for future growth		10.1.3.0-10.1.255.0

In Building B: VLANs subnets and IP Subnets:

Department	VLAN	IP Subnet Address
Sales	VLAN 21	10.2.1.0/24
Marketing	VLAN 22	10.2.2.0/24
And for future growth		10.2.3.0-10.2.255.0

In Building C: VLANs and IP Subnets:

Department	VLAN	IP Subnet Address
Finance	VLAN 31	10.3.1.0/24
Accounting	VLAN 32	10.3.2.0/24
And for future growth		10.3.3.0-10.3.255.0

Network devices are managed by the some of the currently unused VLANs and the IP subnets. And if the company administration was intended and implemented the IP telephony,  consider as an example and then the unused VLANs and the IP subnets are allocated to the voice of the VLANs.