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Would it be possible to have duplicate MAC addresses but different IPs on a home router?

My questions are listed below. I don't have computers with the same MAC. The second connection displays no computer name.

Computer Name, Mac, IP

David 11:22:33:44:55
  1. Is this normal event?
  2. Am I being hacked(aka arp spoofing of some sort?)
  3. What causes it? Can this happen time to time and disappear?
  4. If I used VPN of some sort, can this cause this problem?
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migrated from Mar 1 '13 at 1:06

This question came from our site for system and network administrators.

What do you mean other security? Well, it has WPA level 2 security. So unless they know the security node, I don't think they can get into the system. I do have mac filtering. – jsldfjskaldfsdf Mar 1 '13 at 4:28
You should register on Server Fault, then use the same credentials to log in here in order to re-gain control of this question. – slhck Mar 3 '13 at 12:53

This is normal. Most common one is the same computer having two IP addresses within the space of time that records in the ARP cache live.

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If you are using wireless mac filtering and no other security then someone might just sniff your client computer and use same mac to connect to your wireless network.

You also could have 2 IP addresses on 1 network card -> Network connections -> properties -> ipv4 -> advanced -> ip addresses -> by [Add] button

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Be in alert mode, Have you try to change your MAC ? and see if the other one is still

try and look if teh second IP came back instantly (so maybe is an glicht in your equipment) or the next day (you can suspect neighbor to try access your wifi)

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