Hiding MAC address

[mndar]

How do I hide the MAC(Media Access Control)/Physical/Ethernet address of my LAN card so that scanners like nmap cannot find it ?
I am not sure if it can be done since a Mac address uniquely identifies each node of a network and is used to route packets But there could be a way to prevent a scanner from finding it.

[filthymac]

Certainly you can change your MAC address with macchanger, and having it NATed would hide it from a remote nmap network scan. Otherwise I'm not sure what you're trying to do.

[mndar]

There is a security threat on my LAN. A computer can be easily 'manipulated' if you know its MAC address.
Anyway, I am not talking about changine the MAC (which can be done with ifconfig too). Nor am I talking of remote scans. I am talking about the local scans done by someone on the LAN

[mndar]

Alrite, a simpler question. How do I prevent anyone from getting ping replies from my machine? In other words, I don't want my IP to be listed when someone scans a network

[Jman]

Keep the firewall on. And portscan your systems with something like nmap.

[mndar]

My local LAN IP is 10.12.181.216
I gave the command nmap -sP 10.12.181.200-220
All the computers (all running windows) reported their MAC address but mine did not! I am guessing that the MAC address is found from the NetBIOS info. But this scan was done from my computer itself. I don't know what the result will be when I scan it from another computer.
My other computer is presently down right now. so can't check it.
Anyway, I installed Firestarter yesterday,set ICMP filtering, so that my computer doesn't respond to ping requests and scanned my computer with Sheilds Up on grc.com . It did not show any open ports and the system had True stealth status.
One of my ISP uses pppoe and the other uses NAT. I tried it with both. But this scan was done from an outside computer. I'll have to check the results I get when I scan it from a computer on the Local LAN.

[Twey]

You can disable ping by adding

net.ipv4.icmp_echo_ignore_broadcasts = 1
net.ipv4.icmp_echo_ignore_all = 1

to /etc/sysctl.conf and running sysctl -p.
Check out Nessus.