Defining static addresses
During standard configuration, when there is no DHCP server, Windows uses the automatic IP address configuration process and other parameters for TCP / IP (APIPA - 169.254.X.X).
TCP / IP can be configured manually. Much of the configuration elements are found in the Local Area Connection - Properties window. Next, select Internet Protocol (TCP / IP) and the Properties button. For TCP / IP it is required minimum IP address and Subnetmaske .
Communication with other subnets or the Internet still requires an address for the Default gateway and at least one address for the DNS server .
DNS is also needed for integrating a computer into a Windows Domain.
DHCP Basics
Manually configuring host IPs has some important disadvantages, especially in large networks:
Use of IP addresses should be documented accurately in order to avoid duplicate use of the same address and the use of incorrect addresses and subnet masks.
Changes to the IP address of the main services such as DNS or Default Gateway open many jobs, as each host affected by this change must first be configured.
Portable computers, which are used in different subnets of the enterprise, should be reconfigured after each subnet change.
Dynamic Host Configuration Protocol (DHCP), enables automatic configuration of TCP / IP hosts and prevents problems from occurring. In this case it is possible to configure not only standard parameters such as IP address and subnetmaska, but also a number of additional DHCP options. Here are included eg. IP addresses for the Default gateway and DNS servers, or a server for network services like WINS.
DHCP is Bootstrap-Protokols (BootP) extension and is based on the Client-Server model. The DHCP server has a range of IP addresses that can be provided to clients. Each DHCP client requires startup, and on, at certain intervals, a DHCP server on the network. When it finds and manages to communicate with it receives from it for a certain period of time, an IP address and all the other data needed for configuration. This process is known as Lease.
Assign IP addresses with DHCP
Two different processes are distinguished when assigning IP addresses:
Automatic assignment, during which the DHCP server assigns an IP address to the client within a defined range. The address is associated with the MAC address of the customer for an indefinite time. After deleting DHCP-Caches on the Server, new IP addresses can be started again.
During dynamically assigning IPs, the given addresses are stored in a configuration file. The client, over a specified time (Lease-Time), must confirm the address, otherwise the address remains free and can be assigned to another computer identified on the network.
Assigning IP addresses through DHCP
Successful delivery of an IP address to an unconfigured DHCP client is performed in four steps:
The DHCP client, during the initialization of TCP / IP, sends a broadcast to the local subnet, through which it requires the provision of IP configuration. This sent message is called DHCPDISCOVER (1). The DHCP server, which is active on the network, responds to this request with a DHCPOFFER (2), which contains an IP address and a subnetmask for the client. The client chooses the offer in Lease form and makes it known again on the local network via a DHCPREQUEST (3). In this way, all DHCP servers already know which offer was made available and by client client. The DHCP server, whose offer was selected by the client, finally confirms the choice by sending a DHCPACK (4) (acknowledge), which contains all the information needed to configure the TCP / IP client.
Subnetmaska
When evaluating IP addresses, through address classes, it is sufficient to provide an IP address to identify the network and host address. Subnetmaska (Subnet Mask) is an alternative to the use of address classes. The main advantage is the possibility that the length of the network address extends not only to the level of octets, as is the case with class A through C. With the help of assigning a given subnet mask together with assigning an IP address, There is the possibility that the network address ends at any IP address we prefer.
Subnetmaska is processed by hosts like any IP address and given 32 bit long. It does not consist of any number of binary numbers, but begins with a binary 1 and contains a maximum of a difference in binary 0, eg:
11111111 .00000000.00000000.00000000 or 255.0.0.0
As a rule, the binary subnet mask data, the value of which is 1 indicates the network address. All subnet mask binary digits that have the value of 0 correspond to the host address:
Adresa e IP-së | 192.168.1.100 = | 11000000 | 10101000 | 00000001 | 01100100 | |
Subnetmaska | 255.255.255.0 = | 11111111 | 11111111 | 11111111 | 00000000 | |
Adresa e rrjetit | Adresa e Hostit | |||||
Subnet mask function
Subnetmaska determines which part of the network belongs to the IP address. Therefore, it is mandatory that along with the IP address be given subnetmaska. The subnet mask provides an exact IP address in the network. Hosti, through the subnet mask of his partner in communication, determines how the data should be transmitted to the latter. For this purpose, an EDE (AND) log operator is used that collects the IP address with its subnet mask. Thus, each IP address bit meets the corresponding subnet mask bits. Based on the binary code collection rules, using the logic operator AND, we obtain the network address, for example:
Adresa e IP | 192.168.1.100 = | 11000000 | 10101000 | 00000001 | 01100100 | |
Subnetmask | 255.255.255.0 = | 11111111 | 11111111 | 11111111 | 00000000 | |
Mbledhja | 192.168.1.0 = | 11000000 | 10101000 | 00000001 | 00000000 | Adresa e rrjetit |
Adresa e destinacionit | 192.168.1.200 = | 11000000 | 10101000 | 00000001 | 11001000 | |
Subnetmaska | 255.255.255.0 = | 11111111 | 11111111 | 11111111 | 00000000 | |
Mbledhja | 192.168.1.0 = | 11000000 | 10101000 | 00000001 | 00000000 | Adresa e rrjetit |
No comments:
Post a Comment