[Gllug] Fedora 16 MAC Address

[James Courtier-Dutton]

On 19 April 2012 10:43, Nix <nix at esperi.org.uk> wrote:
> On 18 Apr 2012, Chris Miles told this:
>> This seems to be the core of the issue, all the addresses reported have
>> the top bit set, they are 'locally administered' and overwrite the
>> card's built in MAC.
>
> Uh, the locally administered bit is not the top bit. The locally
> administered bit is the next-from-bottom bit of the top octet. See, e.g.
> include/linux/etherdevice.h:random_ether_addr() in a recent Linux kernel
> tree.
>
> And (unless I've typoed) not all these addresses have that bit set.
>
>> ifconfig allow this locally-administered address to be configured, man
>
> ifconfig is by now very obsolete and frequently misleading (though not
> in this case). You want 'ip link set address'.
>
>> e.g.
>> ifconfig eth0 hw ether ascii-mac-address
>
> ip link set address ascii-mac-address dev (device)
>

Note: Only change the MAC address of an interface when the interface is down.
Otherwise the network will think there are duplicate IP addresses.
I don't actually know if the "ip link set address ascii-mac-address
dev (device)" does an arp poison or not. I probably should.
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