Guy's Simple Litmus Test: How do you assign a client's IP address?
Professionals automatically assign IP addresses for XP desktops Amateurs manually configure the IP addresses on each client machine
Guy's Advanced Litmus Test: How many DHCP Options do you configure?
Professionals configure at least Type 003 Router and Type 006 DNS Servers Amateurs never configure any Scope Options.
Dynamic Host Configuration Protocol (DHCP)
As late as 2004 I read a survey that found 20% of organisations still assign static IP addresses. Reasons included the need to track IP addresses to individual machines and dislike of DHCP. 80%
of respondents trust DHCP and consider it to be the way of the future. My feeling is that in 2006 only about 10% of administrators are 'amateurs' and still refuse to consider DHCP.
It is relatively easy to configure a client so that it automatically get an IP address from the
DHCP server. However, the
benefits of DHCP are greater than just giving out the client IP address. For example, you can also give clients the IP address of the DNS server and the router.
Thus if a DNS server changes its IP, you only have to alter configuration once on
the DHCP scope. This is much better than going to every client and
manually changing the default gateway at each TCP/IP property sheet.
DHCP is a service that you install on Windows Server 2003. The server does not have to be a Domain controller. Once
installed you need to configure a scope or range of IP addresses. My advice is to configure 2 servers (but no more) for each subnet. For example, Server A range 20-120, server B range 121-254
I heard a horror story of how one company had to employ a contractor to alter
the default gateway of all 750 machines by hand. If only they had used
DHCP it would have taken but a minute, a classic of modern methods reducing the
TCO (Total Cost of Ownership).
When you create a DHCP scope, as well as Router (DHCP Option Type 003), it costs little time to add a DNS Server (Type 006) and
also Domain name (Type 015). It is worth checking out over 40 other
automatic settings you can assign at the same time as the IP address.
DHCP Logging
One persistent reason companies gave for not implementing DHCP was that it could not track who was using which IP address. They obviously did not realise that you could turn on Audit Logging.
On the server the DHCP server has to be registered in Active Directory before
it can be activated. Microsoft claim this best practice is stop a tide of unauthorized
DHCP servers on the network. Personally I think it is an unnecessary extra
step! That said, I do recognise that there has been a tendency to have too
many DHCP servers with the risk of duplicate IP addresses if the administrators
are not careful with scope ranges.
On a brighter note, Windows 2000 supports APIPA (Automatic Private IP
Addresses). This was first introduced with Windows 98, if a DHCP server is
unavailable, the client gives itself an IP address in the range 169.254.x.y.
The benefit is that it can communicate with other clients on its subnet, and
since it has a proper IP address, it can keep trying to contact the DHCP server
for a more suitable IP address.
Guy's Challenge - Download
this free device backup utility
(CatTools)
CatTools is a free program for backing up configuration settings on
hardware devices. Here is Guy's challenge. If you
download CatTools, then it will not only take care of backups, but
also it will show you something new about the hardware on you
network. I could give you a money back guarantee - but CatTools is
already free! Thus, I just make a techie to techie challenge, you
will learn more about your network if you:
Over
40 of Guy's litmus tests. Have fun while you learn about Windows
Server 2003. Stacks of ideas to check your servers, networks and
security.
