On Tuesday, May 27, 2014 at 4:58:41 AM UTC-7, tdenh...@gmail.com wrote:   
      
   > We have a Cisco 2901 with multiple WICs and three of the   
   > Routing Interfaces are connected to the same single dumb switch.     
   >    
   > Obviously the interfaces should not normally be connecting to the   
   > same switch, but that's how our system is currently designed.     
   >    
   > The odd thing is when a Windows PC (no IP yet) and another   
   > device (device A,for example IP 10.10.10.1) are both connected to   
   > this same dumb switch, when we try to configure an IP on   
   > the Windows PC, the PC responds with IP address conflict.   
   > We are sure there is no IP conflict, but the message comes up everytime.   
       
   > Even though we can try any random IP on the Windows PC, it always   
   > responds with IP conflict.     
       
   (snip)   
      
   > Maybe PC having the same MAC address across multiple   
   > interfaces causes this????   
       
   > Does anyone know why the PC would think there is an IP   
   > conflict when trying to set the IP?     
      
   Well, this is a little old, but I will reply anyway.   
      
   The test for duplicate IP address is to ARP for your own address, and see   
   if anyone else replies.  Routers should not forward ARP, though they might   
   have proxy-ARP turned on. If proxy-ARP was on, and I don't think it should   
   be, the ARP could go out another interface to the same net, and surprise   
   the Windows PC.   
      
   Use ethernet sniff software, such as tcpdump, and see what packets   
   are floating around.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)