IP address woes

fwor

devonpie wrote: »

How do you set a range for static Ips?

Strictly you don't need to set one. Any address that's not in your router's DHCP range but is still within your subnet address range is available to use as a static address - you just have to make sure that you choose a different one for each PC.

BTW, not all DHCP servers are the same. For example with some you can set them up to ~always~ map each (unique) MAC address to the same IP address - but I've never come across a router that has that level of complexity.

So, in the example I gave above, simply go into the management interface of your router and set a DHCP range that goes from -say- 192.168.0.10 to 192.168.0.100. and that will leave the 9 addresses below that range for devices on which you manually set static IPs.

[Edit: in the example above, the range 192.168.0.101-254 is also outside the DHCP range and could be used for static addresses. I'm not sure about 255 - it might be a broadcast address. Either I've forgotten whether it is or perhaps I never knew whether it is or not...]

tomsolomon

fwor wrote: »

Strictly you don't need to set one. Any address that's not in your router's DHCP range but is still within your subnet address range is available to use as a static address - you just have to make sure that you choose a different one for each PC.

BTW, not all DHCP servers are the same. For example with some you can set them up to ~always~ map each (unique) MAC address to the same IP address - but I've never come across a router that has that level of complexity.

So, in the example I gave above, simply go into the management interface of your router and set a DHCP range that goes from -say- 192.168.0.10 to 192.168.0.100. and that will leave the 9 addresses below that range for devices on which you manually set static IPs.

[Edit: in the example above, the range 192.168.0.101-254 is also outside the DHCP range and could be used for static addresses. I'm not sure about 255 - it might be a broadcast address. Either I've forgotten whether it is or perhaps I never knew whether it is or not...]

Very usefull posts.....
I'm learning IP adresses, classes and subneting ATM. I didn't realy look at using a static addresses in this way before. :beer:

fwor

Tom - I can't take any credit for the scheme. It's a simplified version of the one used in an insurance company where I was once comms manager. The static addresses were reserved for file and print servers, and remote printers, plus the management ports on the hubs and switches.

They also always had the router/default gateway up at x.x.x.200, "for security reasons", though I could never get anyone to explain why that was any more secure than having it on a more sensible address.

The scheme worked fine for all of the small and medium offices, but needed a complete rework from scratch at the data centres...

tomsolomon

It would make perfect sense to have the default gateway IP as x.x.x.0 or x.x.x.1 and reserve ten or so addresses for network resources on a small class C network.

I suppose the thought behind the x.x.x.200 was that, trawlers and port scanners would automatically look for open ports on the default gateway IP, which in most cases would be x.x.x.0 or x.x.x.1? Dunno

devonpie

fwor wrote: »

Strictly you don't need to set one. Any address that's not in your router's DHCP range but is still within your subnet address range is available to use as a static address - you just have to make sure that you choose a different one for each PC.

BTW, not all DHCP servers are the same. For example with some you can set them up to ~always~ map each (unique) MAC address to the same IP address - but I've never come across a router that has that level of complexity.

So, in the example I gave above, simply go into the management interface of your router and set a DHCP range that goes from -say- 192.168.0.10 to 192.168.0.100. and that will leave the 9 addresses below that range for devices on which you manually set static IPs.

[Edit: in the example above, the range 192.168.0.101-254 is also outside the DHCP range and could be used for static addresses. I'm not sure about 255 - it might be a broadcast address. Either I've forgotten whether it is or perhaps I never knew whether it is or not...]

Hello

I still have this problem, although the machines aren't reporting IP conflicts, just that the machine that goes on first gets the Internet and the machine that goes on 2nd is deathly slow. Clearly this isn't right and didn't use to happen.

The message above may sort it, but I don't understand it. Was wondering if anyone could give me an idiot's guide to sorting this?

I'd be most grateful.