On Wed, 25 Feb 2015, Ed Vance wrote to mark lewis:

 ml> yes... and if you have to change the NIC, there'll be a new MAC... 
 ml> the MAC is assigned to the NIC, not the machine... laptops with 
 ml> both cable and wifi capabilities have at least two MACs...

 EV> I'd think the only to change the NIC would if I replaced the 
 EV> Motherboard in this desktop pc.

i'd start by adding a new NIC and plugging it into an available slot ;) you
wanted to not use the one on the motherboard, disable it in the BIOS if it
can be... perhaps you might want gigabyte speeds on your internal network
and the MB NIC is only 10/100 ;) 

 ml> DHCP address reservations (aka psuedo-static) are made based on 
 ml> the MAC...

 EV> As I learned, which ever pc is turned on first around here gets 
 EV> the DHCP Server .100 IP Address, and the next one turned on gets 
 EV> something other than .100 .

here's the thing about DHCP... each machine's DHCP client will (should!)
request the address it had last... some machines are very persistent over
time in asking for an old address they may not have had for 25 connections
or more... the DHCP server will (should!) offer the last address that a
specific client had the last time it was connected... many blackbox routers
(aka those bought at the local circut city or best buy or similar) have
DHCP servers in them but their implementation is generally not as robust as
it could be...

 EV> Thanks for helping me.

not a problem :) 

 EV> As I told Ben, I may have figured a way to keep this XP pc using
 EV> the . 100 IP Address.

the best way to do that is to go to your modem/router thing's configuration
page and in the DHCP section, set a reservation of .100 to your workstation
and set .101 to the other machine... in fact, you might want to set
reservations for all devices on your network so that you know they will
never change... then if at some point you need to renumber your network,
you simply do it in this configuration page... all of the machines i manage
are handled this way ;) 

)\/(ark