[Users] Veth mac generation
dev at parallels.com
Wed Jun 11 09:46:49 EDT 2008
and yes and no.
These upper 3 bytes are reserved for our company, so selecting them you
will never conflict with other devices in network infrastructure.
i.e. the worst what can happen 2 veths will conflict.
On the other hand - you are right, 6 bytes are better :)
Dietmar Maurer wrote:
> Hi all,
> The code to generate mac addresses for veth (generate_mac in veth.c)
> uses the
> Constant SW_OUI for upper 3 bytes, and random values for lower 3 bytes.
> giving 2^24 possible values.
> Isn't it better to use random numbers for all 6 bytes, like the code
> in the linux kernel:
> static inline void random_ether_addr(u8 *addr)
> get_random_bytes (addr, ETH_ALEN);
> addr  &= 0xfe; /* clear multicast bit */
> addr  |= 0x02; /* set local assignment bit (IEEE802) */
> That would make conflict less likely.
> - Dietmar
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