What are the different types of DHCP server?
In an environment that uses static IP addressing, when an administrator installs a new workstation, she looks up an available IP address and the corresponding subnet mask in the IP address table. This table may be written in a notebook or saved on a computer in a spreadsheet. Once she finds the IP address, she needs to determine the correct DNS (Domain Name System) and WINS (Windows Internet Naming Service) server addresses for the workstation to use. In addition, in a routed environment, the administrator needs to ascertain the correct default gateway address for the workstation's subnet. Then she manually configures the workstation with the proper TCP/IP information. For small networks or networks that do not experience many changes, this may be fine There are a number of downsides to administering IP addresses statically. Foremost is human error. If the administrator mistypes the IP address or subnet mask, the workstation may not have connectivity to the resources it requires. If the DNS or WINS server IP addresses are mistyped, the workstation will not be able to perform name resolution. If the default gateway is incorrect, the workstation will not be able to connect to remote subnets and resources. Another downside is maintaining the IP address table. The administrator must continually spend time viewing and searching the address table for available addresses. Once she finds an available address, the administrator must note in the table that the IP address is now in use. Finally, if the network is large and its users move about often, using static IP configurations can be frustrating and inefficient. Problems such as the ones described earlier are compounded with larger networks. == There are four methods of dynamically allocating IP addresses: automatic, dynamic, roaming, and manual. Three of these methods--dynamic, roaming, and manual--use DHCP to allocate the IP addresses. # Automatic allocation. Automatic IP addressing utilizes the client's operating system to allocate a private IP address. Microsoft's Windows 2000 and Windows 98, along with the Apple Mac OS 8.5 and later, are operating systems that support Automatic Private IP Addressing (APIPA). The theory behind APIPA is that small ad hoc networks will be able to achieve basic connectivity without the need for intervention by the administrator. APIPA allows a workstation to configure itself with an IP address in the absence of DHCP or any other IP addressing mechanism. Automatic allocation is a quick and easy solution to the IP addressing problem, but it is only useful in small networks that need basic connectivity without Internet access. Larger environments are typically subnetted to segment network traffic and increase performance. Since APIPA is limited to the 169.254/16 subnet, it cannot be utilized in those environments. The downside to using APIPA even in small networks is the difficulty it may cause in troubleshooting connectivity issues. # Dynamic allocation. Dynamic allocation uses DHCP as the mechanism to allocate IP addresses. The administrator assigns a range of addresses to the DHCP server. The DHCP server, in turn, assigns an IP address in the range to DHCP clients upon request. This range is known as a scope. The administrator, when defining a scope, also specifies the lease duration for any IP address assignments from the scope. A lease duration is the amount of time a DHCP client has exclusive use of an IP address. After the lease duration has expired, the DHCP client must request a new lease from a DHCP server. # Roaming allocation. Roaming allocation can be used in situations where there are areas that users may visit temporarily with their laptops. Such areas may be libraries, classrooms, laboratories, or conference rooms, where users will need a DHCP-allocated address for a brief period of time. The basic configuration of the roaming allocation method is much like the dynamic allocation method, with the notable exception that the lease duration time is very short for the scopes that service these areas. For example, a company may have a conference room where users want to utilize network resources via their laptops. For the roaming allocation method to work, the conference room LAN first needs to be segmented. This is required because a subnet can be serviced by only one scope at a time. The administrator then creates a scope for the conference room subnet. The scope is given a lease duration of about 45 minutes. When users connect to the conference room LAN, they receive an IP address from the conference room scope. Once they leave the conference room, the user can wait for the lease to expire, at which point the laptop will restart the DHCP conversation. They could also release the IP address and request a new one. The roaming allocation method is useful in small, local implementations. Although it can be used on a larger scale, the short lease duration may cause excessive DHCP traffic and additional load on the DHCP servers. # Manual allocation.Manual allocation is another method that can be used in situations where an administrator wants to know the MAC (Media Access Control) address of the DHCP client before assigning an IP address. An administrator may want to do this for security reasons, or she may simply want to know who is utilizing network resources for billing purposes. Manual allocation is typically used in academic settings. Manual allocation can also be used for network devices such as servers and network printers. In this case, the MAC address of the server is used to create a reservation. With reservations, changes can be made to the IP configurations of all servers in a particular scope or even the entire enterprise. For example, if an administrator wants all servers to point to another DNS server, she could simply change the Name Server option for the scope where the servers were located. When a server renews its address lease, it will receive the updated Name Server option. As you can see, manual allocation is a very time consuming and labor intensive. In essence, manual allocation is very similar to using BOOTP. It should be used only in environments that require knowledge of what devices are connecting to the network.
Describe the steps taken by the client and DHCP server in order to obtain an IP address?
Firstly, a DHCP server is needed which distributes the IP addresses. This machine will serve as a base for all DHCP requests and must also have a fixed IP address. Therefore, on a network there can only be one machine with a fixed IP address, the DHCP server.
The basic communication system is BOOTP (with UDP frame). When a machine is turned on, it has no information on its network configuration, and there is nothing special that the user needs to do to find an IP address. In order to do this, the technique used is the broadcast: to find and talk with a DHCP server, the machine will simply send a special broadcast packet (broadcast on 255.255.255.255 with other information such as the type of request, the connection ports, etc.) over the local network. When the DHCP receives the broadcast packet, it will send back another broadcast packet (do not forget that the client does not obviously have the IP address and that therefore cannot be connected to directly) containing all the information required for the client.
It could be believed that one single packet is enough for the protocol to work. In fact, there are several types of DHCP packets likely to be issued either by the client for the server(s), or by the servers to a client:
DHCPDISCOVER (to locate available DHCP servers)
DHCPOFFER (server response to a DHCPDISCOVER packet, which contains the initial parameters)
DHCPREQUEST (varied request from the client for example to extend its lease)
DHCPACK (server response which contains the parameters and IP address of the client)
DHCPNAK (server response to indicate to the client that its lease has expired or if the client announces a bad network configuration)
DHCPDECLINE (the client announces to the server that the address is already in use)
DHCPRELEASE (the client releases its IP address)
DHCPINFORM (the client requests local parameters, it already has its IP address)
The first packet issued by the client is a DHCPDISCOVER type packet. The server responds with a DHCPOFFER packet, particularly in order to submit an IP address to the client. The client establishes its configuration and then makes a DHCPREQUEST to validate its IP address (a broadcast request since DHCPOFFER does not contain the IP address). The server simply responds with a DHCPACK with the IP address for confirmation of the allocation. Normally, this is enough for the client to obtain an effective network configuration, but it can be longer or shorter according to whether the client accepts the IP address or not.
Which three terms describe different types of computers?
Computers
Types | Uses
Personal computer* / laptop ------ Home and office applications
Server -------------------------------- Commercial use and data storage
Super computers -------------------- Military use and weather forcasting
*personal computers in a network are also know as "workstations"
Your computer say tftp no reply from server?
Either from below is possible:
Subnetting is the practice of dividing a network into two or more networks.
Does WiFi cost on your cell phone?
No, unless the place you are at require a charge to use their Wifi, but normally it is a free service
Static versus dynamic network in SIMD interconnection network?
Static- Links between two processor are passive & dedicated buses cannot be reconfigured for direct connection to other processor.
Dynamic- It can be reconfigured by setting the n/w active switching element.with different classes i.e single stage & multistage.
What layers of the Open systems interconnection model does the Internet use?
1) physical - input output devices , cables, modem 2) datalink - switches (MAC address) 3) network - routers (IP address) 4)transport - 5)session 6) presentation 7) application
How do you connect two computers?
You can set up a network. The most simple network consists of only two computers. You can use this network to share files, a printer, or another peripheral device, and an Internet connection.
Why IDS might be useful to an organization?
IDS Intrusion detection system can be configured to alert persons of an intrusion or suspicious activity in the network. An organization will find this useful to meet compliance requirements in strict situations. They can also prove useful in troubleshooting because many intrusion detection systems can capture packets. Today most IDS systems have been replaced with IPS (intrusion prevention systems) because IPS will take action when an signature is fired. A signature is how many IPS systems recognize suspicious activity.
What cable do I use to connect a 12 G4 Powerbook to a Viewsonic PJ503D projector?
Judging from the tech specs page on the Viewsonic PJ503D projector, it takes standard VGA input. The PowerBook G4 12" has a mini DVI out port. So, the adapter you would need is a mini DVI to VGA adapter (which should have come included with the PowerBook, or is readily available at your local Apple store or Apple online).
What are the characteristics that distinguish local area networks from other networks?
loler digan me la respuesta plisss q simple
No. Only protocols that users can see on their screen are considered Presentation Layer based.
Hubs and repeaters operate on the physical layer, because it doesn't do anything with the data, it simply forwards it.
bridge
Why is the maximum number in an IP address 255?
because for the set binary number it will be 11111111 which is in hexadecimal is FF = 255
Basically, the faster the LAN the faster you get information from one system to another. It all comes down to how much data you are transferring (internally) and how quickly you want to get it there.
In most companies, even internal communications seem slow to users at times. Most users want the fastest connection they can get.
How does Amazon.com exploit the network effect?
Amazon.com take that effect into account when they use buyer recommendations as the selling point for their products.
Is Scan all removable media before uploading it to your computer a physical security measure?
No, not really. Physical security would be locking the computer in a closet, or somehow blocking the access ports for removable media with a locked door or gate so that someone who didn't have the key wouldn't even have the option of using removable media.
network port
Which IP address below is a reserved IP address?
Reserved IP addresses are
10.0.0.0 to 10.255.255.255
172.16.0.0 to 172.31.255.255
192.168.0.0 to 192.168.255.255
and
169.254.0.0 to 169.254.255.255
Every address in these ranges is considered reserved or private,
meaning the internet will NOT route to them without an NAT.
What happens when a final approver rejects a managing account setup screen?
The setup returns to the Active Work Queue for correction and resubmission
Can I connect any devices other then computers to my network hub or switch?
You can connect any device that takes an ethernet cable! PS3's, Xboxes or any other game console will work just fine.
What commands is used to ping a multi-function device?
The trace route command is used to ping a multi-function device.