Ernst Lopes Cardozo
New Around Here
Hi all,
Let’s take one step back. DHCP is a great tool since it allows us to do any address (and mask, default gateway, DNS servers, etc.) management in one place, rather than going to each network node to set or change its configuration. When that day comes that circumstances force you to move your network to a different subnet, you will know how useful this is. Same case if you need to change DNS servers, etc.
For this to work, it is paramount that all network nodes use DHCP to request their network parameters, and do so regularly. Setting the lease period to indefinite would force you to reboot all devices should a change in the network parameters be necessary.
Of course, on your average home network, such problems are relatively small, but … you may find that you have to declare a network maintenance window where the wife and kids are off-line for a moment. If you have to open each box to change network settings manually, that moment might take more than a few minutes.
To me, this is the primary function of DHCP. Thereafter, some (many) network admins like to play with addresses, either to make it simple to recognize what type of device they are dealing with (“if it is below 10, it must be a server, if …”) or to “find intruders”. If you want that, set predefined IP addresses in your DHCP server. At least, when you need to change network a parameter, you can do it in one place. The danger of using such “fixed” numbers, is that you may start to put this numbers in scripts and other places. When the need to change comes, you will have a hard time to remember / find out where those places are and why certain services and devices stopped working. DHCP and DNS have been developed just to avoid those pains, so smart people use them.
PS, there is a simple and free application “SoftPerfect WiFi Guard” that can show you previously unknown WiFi devices the minute they enter your network.
Let’s take one step back. DHCP is a great tool since it allows us to do any address (and mask, default gateway, DNS servers, etc.) management in one place, rather than going to each network node to set or change its configuration. When that day comes that circumstances force you to move your network to a different subnet, you will know how useful this is. Same case if you need to change DNS servers, etc.
For this to work, it is paramount that all network nodes use DHCP to request their network parameters, and do so regularly. Setting the lease period to indefinite would force you to reboot all devices should a change in the network parameters be necessary.
Of course, on your average home network, such problems are relatively small, but … you may find that you have to declare a network maintenance window where the wife and kids are off-line for a moment. If you have to open each box to change network settings manually, that moment might take more than a few minutes.
To me, this is the primary function of DHCP. Thereafter, some (many) network admins like to play with addresses, either to make it simple to recognize what type of device they are dealing with (“if it is below 10, it must be a server, if …”) or to “find intruders”. If you want that, set predefined IP addresses in your DHCP server. At least, when you need to change network a parameter, you can do it in one place. The danger of using such “fixed” numbers, is that you may start to put this numbers in scripts and other places. When the need to change comes, you will have a hard time to remember / find out where those places are and why certain services and devices stopped working. DHCP and DNS have been developed just to avoid those pains, so smart people use them.
PS, there is a simple and free application “SoftPerfect WiFi Guard” that can show you previously unknown WiFi devices the minute they enter your network.
