First, if you skipped ahead to this section, go back and read the previous sections.
A collection of tips will not replace knowing what the heck you're doing.
If you're not connected to the Internet, and don't already have one or more IP
networks assigned to you, use the addresses reserved for this purpose.
They are, 10.x.x.x, 172.16.x.x-172.31.x.x, and 192.168.x.x (seeRFC 1597)
Create a subnet address policy (e.g., .1-.5 reserved for routers, .1 always the
default route, .6-.30 reserved for static IP's such as servers, .50-.254 dynamic
through bootp/dhcp.)
Use DHCP or BOOTP to assign workstation addresses. When it comes time to change
(after your network has grown a bit), you'll thank me.
Meticulously track static IP assignments. Create a central database or document
listing all static IP's and their associated devices.
Label router interfaces with their addresses.
Keep a current diagram of your subnets and router connections (include detail
on router interface addresses.) If you get into trouble, it'll save you two hours of
onsite time if you have to call someone in to help. Personally, I use SmartDraw for
this purpose (http://www.smartdraw.com/.)
Although Visio also works well, SmartDraw (IMHO) is easier to use and the price is
right.
If you have IP-enabled servers, use a firewall. If you are using Windows-based
file sharing and have no firewall, use a non-IP protocol to do it (IPX or NetBEUI).
You will then need to set either IPX or NetBEUI as your default protocol. Or, get a
firewall. IPRoute from Dave Mischler
(http://www.mischler.com, $50US) can be used
as an effective, low cost firewall, and it'll run on any '386 or better PC with two
NICs; or, if you want to experiment with putting your LAN on the Internet, a low cost
and very secure way to do this is with IPRoute and an old '386 PC with a good serial
port chip and modem.
[Windows Only] If a firewall is not an option, look at BlackICE Defender
http://www.networkice.com/html/blackice_defender.html, which I use
and recommend highly for servers. For personal use, look at ZoneAlarm
(http://www.zonealarm.com/), which
is effective bidirectionally, but requires too much user intervention to be
used for servers in a lights-out environment. And you can't beat the price. :-)