After this, click "Next". Click "Next" on the compatibility window, and in the next window keep the default option of "Domain Controller for a new domain" selected, and click "Next". In this tutorial we will create a domain in a new forest, because it is the first DC, so keep that option selected. Now we have to think of a name for our domain. If you own a web domain like "visualwin.
Active Directory domains don't need to be "real" domains like the one above - they can be anything you wish. So here I will create "visualwin. Now in order to keep things simple, we will use the first part of our domain "visualwin" , which is the default selection, as the NetBIOS name of the domain. The next dialog suggests storing the AD database and log on separate hard disks, and so do I, but for this tutorial I'll just keep the defaults.
MSI software packages can be kept when you will distribute packages as I said, AD has a lot of different features. Once again, I will keep the default selection but it can be changed if you wish to use the space of another drive.
I've heard that Microsoft's NT-based server can do it. Microsoft has software to make Windows NT do this. I don't have an answer for this, but will offer a little discussion. In general, you are faced with the choice: 0. It would be good if I could find out the gotcha's of such a setup.
Can you limit which MAC addresses are allowed to roam? Sites may choose to require central pre-configuration for all computers that will be able to acquire a dynamic address. A DHCP server could be designed to implement such a requirement, presumably as an option to the server administrator. See section below on servers that implement this. It is possible that some servers implement private MIBs.
How long should a lease be? I've asked sites about this and have heard answers ranging from 15 minutes to a year. Most administrators will say it depends upon your goals, your site's usage patterns, and service arrangements for your DHCP server.
A very relevant factor is that the client starts trying to renew the lease when it is halfway throug h: thus, for example, with a 4 day lease, the client which has lost access to its DHCP server has 2 days from when it first tries to renew the lease until the lease expires and the client must stop using the network. During a 2-day outage, new users cannot get new leases, but no lease will expire for any computer turned on at the time that the outage commences.
Another factor is that the longer the lease the longer time it takes for client configuration changes controlled by DHCP to propogate. Some relevant questions in deciding on a lease time: Do you have more users than addresses? If so, you want to keep the lease time short so people don't end up sitting on leases.
Naturally, there are degrees. In this situation, I've heard examples cited of 15 minutes, 2 hours, and 2 days. Naturally, if you know you will have 20 users using 10 addresses in within a day, a 2 day lease is not practical.
Are you supporting mobile users? If so, you may be in the situation of having more users than addresses on some par ticular IP number range. See above. Do you have a typical or minimum amount of time that you are trying to support? If your typical user is on for an hour at minimum, that suggest a hour lease at minimum. How many clients do you have and how fast are the communications lines over which the DHCP packets will be run? The shorter the lease, the higher the server and network load.
In general, a lease of at least 2 hours is long enough that the load of even thousands of clients is negligible. For shorter lea ses, there may be a point beyond which you will want to watch the load.
Note that if you have a communication line down for a long enough time for the leases to expire, you might see an unusually high load it returns. If the lease-time is at least double the communication line outage, this is avoided. How long would it take to bring back up the DHCP server, and to what extent can your users live without it?
If the lease time is at least double the server outage, then running clients who already have lease s will not lose them. If you have a good idea of your longest likely server outage, you can avoid such problems.
For example, if your server-coverage is likely to recover the server within three hours at any time that clients are using their addresses, then a six hour lease will handle such an outage. If you might have a server go down on Friday right after work and may need all Monday's work- day to fix it, then your maximum outage time is 3 days and a 6-day lease will handle it.
Do you have users who want to tell other users about their IP number? If your users are setting up their own web servers and telling people how to get to them either by telling people the IP number or through a permanent DNS entry, then they are looking for an IP number that won't be changing. While some sites would manually allocate any address that people expected to remain stable, other sites want to use DHCP's ability to automate distribution of relatively permanent addresses.
The relevant time is the maximum amount of time tha t you wish to allow the user to keep their machine turned off yet keep their address. For example, in a university, if students might have their computers turned off for as long as three weeks between semesters, and you wish them to keep their IP address, then a lease of six weeks or longer would suffice.
I believe this rational is workable if the summer hiatus is no more than 2 months. One year If a user has not used their address in six months, then they are likely to be gone.
Allowing administrator to recover those addresses after someone has moved on. How can I control which clients get leases from my server? There is no ideal answer: you have to give something up or do some extra work. DHCP servers that support roaming machines may be adapted to such use. You still depend upon the other clients to respect your wishes.
This would have to be done using a mechanism other than DHCP. DHCP does not prevent other clients from using the addresses it is set to hand out nor can it distinguish between a computer's permanent MAC address and one set by the computer's user. What are the Gotcha's? Net result is problems using the nodes, possibly intermittent of one or the other is sometimes turned off.
One scenario is a client that loads its OS over the network via tftp being directed to a different file possibly on a different server , thus allowing the perpetrator to take over the client.
Given that boot parameters are often made to control many different things about the computers' operation and communication, many other scenarios are just as serious. The definition of DHCP states that implementations "should" honor this flag, but it doesn't say they "must". DHCP servers and relay agents use their knowledge of what LAN the client-station is on to select the subnet number for the client-station's new IP address whereas such switches use the subnet number sent by the client-station to decide which virtual LAN to put the station on.
The only way the DHCP server can allocate addresses on one of the LAN's other network or subnet numbers is if the DHCP server is specifically written to have a feature to handle such cases, and it has a configuration describing the situation. Examples are: for security purposes, for network management, and even for identifying resources.
Dynamic configuration of the IP numbers undercuts such methods. For this reason, some sites try to keep the continued use of dynamically allocatable IP numbers to a minimum. The client first connects to the home site and receives an address from one of the two serves. It is of course NAK'ed and the client receives an address appropriate for the remote site. The client then returns home and tries to use the address from the remote site.
The server that holds the previous lease will offer the address back to the client but there is no guarantee that the client will accept that address; consequently, it is possible for the client to acquire an address on the other server and therefore have two leases within the site. But in a very mobile environment, it is possible for these transient clients to consume more than their fair share of addresses.
This can result in some functions working while others are not, or functions working when the client is set up manually, but failing to work when set to use DHCP.
The length of the lease can mean the difference between having to go to every affected client and rebooting it, or merely waiting a certain amount of time for the leases to be renewed. Note: one workaround is to foo l with the client computer's clock. What features or restrictions can a DHCP server have? While the DHCP server protocol is designed to support dynamic management of IP addresses, there is nothing to stop someone from implementing a server that uses the DHCP protocol, but does not provide that kind of support.
These are independent "features": a particular server can offer or not offer any of them: o Manual allocation: the server's administrator creates a configuration for the server that includes the MAC address and IP address of each DHCP client that will be able to get an address: functionally equivalent to BOOTP though the protocol is incompatible. An IP address, once associated with a MAC address, is permanently associated with it until the server's administrator intervenes.
This is pretty obvious, though someone might have a server that forces the pool to be a whole subnet or network. Ideally, the server does not force such a pool to consist of contiguous IP addresses. This is the basic support for "secondary nets", e. Note: this is a feature that might be used to assign different client-groups on the same physical LAN to different logical subnets. Following are some features related not to the functions that the server is capable of carrying out, but to the way that it is administered.
Even better is the ability to make the server do this via a command that can be used in a script, rdist, rsh, etc. What freeware DHCP servers are available? This is not necessarily a complete list Bootp server: Bootp 2. Z Bootp server version 2. Keio Univ. What commercial DHCP servers are available?
What freeware DHCP clients are available? Which vendors of client software currently support DHCP? This is not necessarily a complete list Shiva: proxy client for remote users in Lanrovers and Netmodems Hewlett-Packard NetManage: Chameleon 4.
What are the DHCP plans of major client-software vendors? Open Transport 1. A shrink wrap version of Open Transport is planned. This is not necessarily a complete list. Starting with version 9. Version 8. Xyplex Version 5. Support for the broadcast flag introduced in a maintenance release of 2. I haven't found out anything about support for the broadcast flag.
ACC Version 7. Novell MPR The same as for their server. DHCP requires disk storage or some other form of reliable non-volatile storage , making the task of DHCP service more compatible with servers than with dedicated routers. The large -scale routers i. But there are a number of types of servers that can be configured to route and serve DHCP.
This includes Novell servers and computers running Unix. There are also units designed to handle two or more aspects of your Internet connection, e. One example is Farallon's Netopia Internet Router mentioned above under commercial servers. The reason is that in maintaining and troubleshooting routers, it is important to know its exact configuration rather than leaving that to be automatically done, and also that you do not want your router's operation to depend upon the working of yet another server.
It may be possible to configure some types of more general-purpose computers or servers to get their addresses from DHCP and to act as routers. Also, there are remote access servers, often which are usually not true routers, which use DHCP to acquire addresses to hand out to their clients.
You can get this support in NetWare 3. Which implementations support or require the broadcast flag? The broadcast flag is an optional element of DHCP, but a client which sets it works only with a server or relay that supports it. DHCP client support added with version 3. Version 3. Microsoft Windows 95 Does not set the broadcast flag. What servers support secondary subnet numbers?
These are not complete lists The following servers can handle dynamic allocation on secondary subnet numbers: o IPTrack version 2. To make use of this ability, you need a DNS server that supports this feature. These pr oducts might support one or both of these uses.
Some choices: o Use no server at all for the Windows 95 clients: set the addresses in each client's setup. Do any servers limit the MAC addresses that may roam? What analyzers decode DHCP? All NT software includes a remote agent for it. What administration tools administer DHCP configurations? How do I make a client give up its lease? This is a general question, but the answer is of necessity specific to the client-implementation.
Answered by:. Archived Forums. Directory Services. Sign in to vote. I have a network with 3 servers. I am starting to errors in the client logs like: - Windows cannot determine the user or computer name. Any help or a point in the right direction would be very much appreciated. Thanks -JG. Tuesday, May 10, PM. This posting is provided "AS IS" with no warranties or guarantees , and confers no rights. Wednesday, May 11, PM. From what you posted, I see a DNS problem. Thanks for the response MrX.
Thanks again. I don't recommend having only one DC. I have added the print out for nslookup on the client machine. Which machine is Do you mean You still have not followed what I suggested in my first reply.
Is For more information, refer to what I mentioned in my first reply. Wednesday, May 11, AM.
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