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What's the advantage to a constant MAC address anyway? There must be a reason for it, but my first reaction to this article was to see if I could change mine.
by paulgb 13y ago
What's the advantage to a constant MAC address anyway? There must be a reason for it, but my first reaction to this article was to see if I could change mine.
- aroch 13y agoNetwork's that whitelist devices by MAC and device registration/provisioning by MAC. And debugging network is theoretically easier when every device has a unique MAC. There are several applications for OSX and various *nix distros that run at boot and randomize MACs. SpoofMac is probably the most well known: https://github.com/feross/SpoofMAC https://github.com/feross/SpoofMAC
- MAGZine 13y agoThis is perfect--I'm definitely going to set this up. I'd just like a background service for my Android device that would also randomize my MAC address... (perhaps it's time to investigate android development :P)
- paulgb 13y agoI'd buy that app :) Unfortunately (from the apps that I've seen) it looks like only a rooted Android could support it.
- RyanZAG 13y agoYes, definitely rooted only - Linux will block any attempt to change the MAC without root access. That said, I've got a rooted android and change my mac all the time. Especially useful for coffee shops and airports.
- jcampbell1 13y agoYou often get reassigned the same ip address. This is nice for things like port forwarding. I am not sure this is enough of a reason.
- hobbes300 13y agoCollision avoidance mostly.
- rikkus 13y agoIf an unique identifier is needed, it can still be generated on a short term basis. Make it a GUID and we have generators ready that can do this without risk of collisions.
- Robin_Message 13y agoNot in less than 46 bits, which is all history has given you.
- jws 13y agoAt the link level, your MAC is your unique address. First: You do not want a MAC collision. I have worked with hardware that sometimes picked a non-unique MAC and your life gets really weird and sucks away a lot of debugging time to find out why impossible things are happening. Continuing – It made ethernet easy to implement. They could have added some complicated address negotiation protocol and then handled address collisions when partitioned networks healed, but it was "olden times" and something that complicated would not have gained traction. Fast forward to Wi-Fi. The reason you have Wi-Fi instead of any number of other wireless ideas that died is because it looks like ethernet so people didn't have to think much about it, so you inherit that baggage. If you really want to change your MAC address then you will want to make sure you aren't going to collide with anyone else. The odds are tiny, but it would be rude to ruin their day. Fortunately, there is a locally administered range of MAC addresses. If your first octet's last digit is 2, 6, a, or e then you are a locally administered unicast address. Assuming your network segment doesn't have an administrator actively handing out local addresses, drop 56 random bits in the remaining octets, cross your fingers, and bring up your network stacks.
- nwh 13y ago> First: You do not want a MAC collision. I have worked with hardware that sometimes picked a non-unique MAC and your life gets really weird and sucks away a lot of debugging time to find out why impossible things are happening. I can confirm. Working with a bunch of Chinese hardware with non-unique MAC addresses is painful. It was easier to buy new NICs with real serial numbers than to work out how to fix them.
- skywhopper 13y agoWifi drivers could easily deal with this risk by providing specific MAC addresses only to specific networks. So you lock in your home network and work network, but randomize other unknown WAPs. Or better yet, just turn off wifi when you're away from trusted WAPs and use your cellular data.