Assign IP as static from DHCP pool?

ip address

I've done the same thing when the IT guy is unavailable with no problems either, good question though.

The admin is correct that is not a good idea at all and would cause a problem at some point!

The whole idea of DHCP is to have a central control for automated addressing... yer?
But for that to work efficiently and correctly the DHCP server must maintain control of all the network devices connected.

When you statically / manually set addressing on a device (DHCP off) you run the risk of the DHCP server reassigning that
same I.P address to another device when the DHCP server considers the temporary lease it initially issued as expired.

Then you have a I.P conflict and one or more devices ends up being dropped from the network until it's resolved.

The proper way to connect a MFD to a network using DHCP is to have the administrator reserve a I.P address to the unique MAC address on the MFDs NIC.

This way when MFD is powered up the DHCP server will issue it with the very same I.P address each and every time.
And because it's reserved the DHCP server knows not to issue that address to any other device on the network.

You can safely set a static I.P if it is outside the DHCP server scope range though (but you still should check with admin before doing so).

Example

The DHCP server in question has only been configured to issue addresses between 192.168.0.1 to 192.168.0.50.
So you could give the MFD the I.P 192.168.0.51 as this lays outside of DHCP server's scope range.

ip addresses

You are right. That was some very good info.

Daz beat me to the punch. I always have the admin reserve the ip and set it as a static address. I do have one location that the machine is in dhcp but they use the hostname of the copier to set the print driver and print queue.

I agree with Spock... If you have to set up an MFD via DHCP (or as I call it: Doesn't Hardly Connect Properly), always set the user's print drivers with the DNS name so that they'll hopefully be able to find the correct device, this all depends though on how fast the DNS servers refresh. I've had a few large customer environments where the DNS servers would take forever to refresh and a pile of VLAN's would end up with their workstations pointing to an old IP address.
Static addresses are always your best route...

Let him set it up DHCP but have him sign a paper saying it will cost him $100.00 each time you have to go out to reasign the IP of the print driver.
IT people know IT.
We know IT and how our print controllers work.

Leaving a MFD set to DHCP does work great if it's done correctly.

All you need to do is have a I.P address allocated to the MAC address of the MFDs NIC.
Then the MFD will always be given the same I.P address by the DHCP server, it's as simple as that really.

From a administrative point of view a medium to large network is by far easier to manage on DHCP.
Just the thought of having to go around and manually configure 100+ workstations and devices sends shivers down my spine LOL.

DaZ has pretty well summed it up for the DHCP viz Static IP address.

Just to add a comment for those that 'have not had any problems' snagging an IP address assigned by the DHCP server and making it static. If you don't have the network admin assign that IP address to the mfp's mac, you run into the following........

Eventually, you will run into a situation where the copier is turned off for the night and there is a request for an IP from the DHCP server. The server may assign away that IP addy you snagged. Most of the time, the server will query the network to verify an address is unused and the copier has a chance to respond that it is using it. Not if it isn't turn on at the moment. That is why you mostly don't have a problem with 'stealing' an address.

On the flip side, you could use a strictly dynamic IP and machine name to identify the mfp in the PCs driver. I've mostly not had any trouble with that method. However, that puts a whole lot of faith in the entire network working in top form. DNS while seemingly simple in concept is apparently a bitch in practice.

Ok, in an enterprise style network, that all seems fine and dandy! But what about the number of accounts that you have that do not use a server for their network activity?

In simple practice, yes, I agree that the admin should assign an IP. But what about the others that don't!? Outside of the enterprise network environment... I support the "DHCP Boot/Assign" method. I have done more than I can count and find no problem with it, in an simple network environment. Thank God for ARP!!





What the hell is ARP? Well cool then... Address Resolution Protocol - Wikipedia, the free encyclopedia

for the sake of techy talk... what say you?

With no one managing the network, there probably is no safe fool-proof ip assignment. I've been where you are more times than not. However, I still say using the DHCP assigned address is still not the better solution.

IMO, the better solution, until the customer changes the simple little router that is most likely handing out the addresses, is to use an address outside of the range of addresses that is being assigned by the DHCP/router.

If addresses are being assigned in the low end such as 1, 2, 3 or 100, 101, 102, then I would assign an address up around 240 - 252. I always stay away from 0, 1, 2, 253 and 254.

There is another handy little utility that I used to use a lot more than I do now called something like madpingger. What it would do is ping every address within a defined range to see if anything is using that address. I drag it out every now and again when I am a bit confused about the network.

Lately my confusion level has shifted more toward domain clusters and Novell and changes in authentication. Ethereal works better for that.