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These days I had problem with my internet connection.

I have a static IP connection, but some time ago I couldn't access the internet. A friend helped me and we found out that the IP and MAC-address of my PC were assigned to another user in my network.

This user is using some program which is giving him this precious information of mine (i.e. the addresses). The Ubuntu PC in question is acting like a web server and I need a way (if there exists one) to hide this important information, since I need my server to run all day with active internet connection.

The ISP can't avoid this problem.

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migrated from Oct 25 '11 at 11:24

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

Read this post:… – Chris Ting Oct 25 '11 at 11:19
someone needs to give up their static IP. Can you find out why the other user is using a static IP? – tombull89 Oct 25 '11 at 11:21
There's not a way to hide the MAC/IP from your end. The service provider could do it in a couple of ways...but you're indicating that the service provider is being less than helpful. You could come at the problem another way and use dyndns or something instead of a static ip. – RobotHumans Oct 25 '11 at 11:57
Who's paying for the IP? If you're paying, and your friend is stealing it, he's not a very good friend. If he's paying for it, get your own! – Chris S Oct 25 '11 at 12:26
... Cont. by DHCP. Since it sounds like you have a static IP, not DHCP assigned, your ISP has to come to terms with tracking down the offender or assigning you a new IP. If they won't do it, you need a new ISP. – Fiasco Labs Oct 25 '11 at 15:59

Based on your situation. try to restart your server. Scan your network for any open-end connection (Wireless only). Fix IP slots and registers every MAC to the server (If possible).

Following tools can be used for guarding against the ARP attack

 ARP Watch
 ARP guard
 ARP Defender
 ARP Inspection
 Network Monitor Tools

You can see the reference from here

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