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MAC address as random input?

MAC address as random input?

Posted Jul 25, 2012 18:45 UTC (Wed) by kleptog (subscriber, #1183)
In reply to: MAC address as random input? by BenHutchings
Parent article: Random numbers for embedded devices

Note that the default varies by implementation. Various versions of windows default to privacy extensions.

Privacy extensions means your IP changes regularly, usually once a day. For servers you don't want that, but for client PCs the tradeoff is different. If it bugs you you can set the IP address yourself.

Note the link-local address always includes your MAC address, but that address never leaves the LAN, and everyone on your LAN needs your MAC address anyway to talk to you.

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MAC address as random input?

Posted Jul 26, 2012 12:18 UTC (Thu) by farnz (subscriber, #17727) [Link]

More accurately, it adds an extra IP that changes regularly; you still have the permanent IP that you would have if you didn't enable privacy extensions, but you also have a temporary IP that changes, and that is used in preference to your permanent IP for outgoing connections.

The idea is that if you give me your permanent IP, I can connect to you. If you don't, the only IP of yours I know about is your temporary IP, which changes regularly - so while it's fine for the duration of communication you initiated, it's not useful in a few days time.

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