Two elementary questions on LANs

[Ed Greshko]

On 06/19/2011 02:44 AM, J. Alex Aycinena wrote:
>
> I have desktops and laptops on my local LAN that each dual-boot with
> F15 and Windows and each have a wired and wireless LAN connection. My
> router acts as the DHCP Server but doesn't have the capability to
> assign a pre-defined IP address to each machine based on its MAC
> address. Besides, I would like each machine to have a different
> address assigned depending on whether it was running Fedora or Windows
> in a given instance. I don't want to assign fixed IP addresses to the
> clients - I want them to get the addresses from the server so that
> they don't have to be reconfigured if they go off of my LAN and onto
> another (e.g., the laptops). But I would like to set them up to each
> request a unique IP address from the server and to identify themselves
> differently depending on whether it is the wired or wireless
> connection such that they are very likely to get what they request.
> (The reason I want this IP address stability is because I use Backuppc
> to back each up and now the volatility of their IP addresses is making
> it so that that doesn't work too well. The volatility is caused by
> other more transient devices getting on and off the network and
> causing the reassignment of previously assigned addresses to not occur
> very often.)
>
> If this file does exist, can I simply edit it to put the IP address I
> want assigned to each LAN interface of each machine into it and thus
> achieve what I want?
>
> Can I simply put in a different 'option host-name' value into the
> wired vs. wireless files in this directory to achieve my goal of
> distinguishing them (e.g., HPfedora vs. HPfedora-wl) for a given
> machine or OS (e.g., HPVista vs. HPVista-wl)?
>
> Or are there other configuration files where I should put this
> information that will cause the client to send out the DHCP Request
> with the IP address and host-names that I want?
>
> I would be grateful for your comments.
>
>

Well....my first reaction is that you maybe fighting a losing battle.
Also, it would be good to know the make/model of your router....

I say this because even if your router doesn't have configuration
choices for reserving IP addresses based on MAC address....that is most
likely what it is doing.
Since the MAC address is in the hardware I would venture to say that the
IP address being assigned to an interface is the same no matter if you
boot to Linux or Windows.

Also, I don't know of any DHCP server that makes use of the supplied
host name to make its reservation decisions.  Frankly, I've not
researched that and haven't read the DHCP RFCs in a long time.

In the past, with other client/server situations, I've found mixed
results when trying to adjust client settings to get a given outcome.
So, rather than work against the system and try to maintain "special"
cases I've either configured my client to ignore configuration
information supplied by the server or configured the server to supply
the information I desired.