No matter how prepared and how well documented the network is, sometimes techs forget some basic configurations sometimes. It’s never intentional, but sometimes there are small configurations that we just need to double check. Below is a list of some things that I’ve seen (and have) forgotten to double check when doing a project.
Subnets other than 24-bit
I don’t often come into contact with many subnets outside of the standard 24-bit class C subnet mask (255.255.255.0). Yet every time I do run into another subnet mask, I and many other techs, forget that and use the standard. I now try to remember to double check the subnet mask if it is standard…and if it isn’t I try and triple check it. Personally I haven’t found many good reasons to ever install a network with anything other than the standard 255.255.255.0 subnet mask in most networks.
Default Gateway other than .1
Due to the amount of networks I’ve work on, every time I enter a static address I enter the .1 for the default gateway. For networks with another class other than C, you may not have .1 as the default gateway due to the minimal host available you’ll find other gateways than .1, so it’s best to double check this, especially it it’s not .1
DNS IP Addresses
I generally like to keep the servers in the first 10 or 20 addresses on the network and generally for DNS I like to use .2 and/or .3. Yet not every network administrator can or does it the same way, so I generally check the DNS servers address several times to make sure that they are set up correctly.
In some networks, and sometimes in my networks, WINS can be forgotten and become a mess. If the network uses WINS, make sure it’s set up and working correctly and if the computer supports it, is pointing to the correct address.
DNS suffix lists
Having missing DNS suffixes in DNS can cause nightmares in your network as computers don’t know how to get to their destination. If not implemented I recommend that you use Group Policy to set a primary suffix and a suffix search order for each computer account.
These are some of the most simple configuration items on your network, but the ones that are most often overlooked. I think largely because we assume we know the answers, but a simple mistype can make a deployment of hardware or software a nightmare.