the EUI-64 builds a 64bit field from a 48bits field the MAC address.
someone says it is for the following reason
The motivation for inverting the 'u' bit when forming the interface identifier is to make it easy for system administrators to hand configure local scope identifiers when hardware tokens are not available. This is expected to be case for serial links, tunnel end-points, etc. The alternative would have been for these to be of the form 0200:0:0:1, 0200:0:0:2, etc., instead of the much simpler ::1, ::2, etc
section 2.5.1 of RFC 2373
However, two bytes are added between the OUI and host part so the EUI-64 is a form of abstraction of the MAC address.
the sentences that are taken from the RFC2373 should have the following meaning:
0 0 0 1 1 2
|0 7 8 5 6 3|
(notice the position of u bit inside first byte of eui-64 if u bit is set first byte is 0x02)
if this spec were changed so that the u bit was used without inversion then to build a local scope 64 bits identifier for a serial interface (for an interface that hasn't its own MAC address) would require to set the u bit so:
0200:0:0:1 should be used instead of
for the host portion of a serial line
the final 1 comes from the fact that the address cannot be made of all zeros.
instead by using an inverted u u=1 means global u=0 means local.
Now, that the specification is made we need to use it.
The first remark is that we don't need to wast a /64 ipv6 prefix over a point-to-point serial link just to say something.
so when mapping a MAC address for a LAN interface they set the u bit and you need to think to your OUI bytes with a 2 in first byte.
I agree I would have been easier without setting it to recognize the MAC address.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.