ESP8266 Community Forum

- Tue Nov 03, 2015 3:34 pm #32954 I am looking to generate MAC addresses for my devices.

What I have read is that:

"The MAC addresses are not randomly generated. The first half of the MAC address is distinct and is assigned by IEEE to specific manufacturers. 00-E0-B8 for instance is assigned to AMD so multiple AMD NICs can begin with 00-E0-B8 (they and the other vendors have additional codes as well) and the second half will be some sequential number to make sure that two NICS from the same manufacturer can never have a conflict. 3COM NICs on the other hand have assigned 02-60-60, so the following sequential number can be the same as another manufacturer's sequential number because the vendor code prefix will be different."

https://answers.yahoo.com/question/index?qid=20110227215246AA5lQu5

I looked into getting a unique range from the IEEE (Institute of Electrical and Electronics Engineers http://ieee.org)but I assume there is a cost from reading on their site.

I am making two devices that I want to take to different places (aka networks) quite frequently. I am just concerned that when I plug them into networks that they will have conflictions with computers. Is this a valid concern? The networks are home networks and will only have a couple computers on them.

If I use a generator (i.e. http://www.miniwebtool.com/mac-address-generator/) should I be fine?

Any concerns or non-concerns welcome.

Edit: HTML code problem

- Tue Nov 03, 2015 3:41 pm #32956 Maybe I asked too soon, which happens.

I did some more digging and found that:

"There are actually 4 sets of Locally Administered Address Ranges that can be used on your network without fear of conflict, assuming no one else has assigned these on your network:

x2-xx-xx-xx-xx-xx
x6-xx-xx-xx-xx-xx
xA-xx-xx-xx-xx-xx
xE-xx-xx-xx-xx-xx

Replacing x with any hex value."

http://serverfault.com/questions/40712/what-range-of-mac-addresses-can-i-safely-use-for-my-virtual-machines

I also found the list of all MAC address prefixes if anyone ever was wondering (http://standards-oui.ieee.org/oui.txt).

- Wed Nov 04, 2015 3:32 am #33004 May I ask why do you need to change the MAC address?

- Sat Nov 14, 2015 4:44 pm #33987

May I ask why do you need to change the MAC address?

I guess I was assuming I had to set a MAC address on the devices... I was supposing that they didn't come with a default MAC address.