I'm setting up a computer lab in which many Raspberry Pis are going to acquire IP addresses via DHCP. I'd like to have the DHCP server to differentiate between Raspberry Pis and other clients.
What are the organizationally unique identifiers (OUIs) for the Ethernet cards on Raspberry Pis with which I might discriminate Raspberry Pis from other DHCP clients?
(I am aware that MAC addresses can be spoofed and am assuming that the DHCP clients are not hostile.)
28:CD:C1 2C:CF:67 B8:27:EB D8:3A:DD DC:A6:32 E4:5F:01 MA-L: Mac Address Block Large (previously named OUI). Number of address 2^24 (~16 Million)
3A:35:41 CID: Company Identifier. This prefix will not be used for globally unique applications. Number of address 2^24 (~16 Million)
Sources:
https://maclookup.app/vendors/raspberry-pi-trading-ltd
https://maclookup.app/vendors/raspberry-pi-foundation https://regauth.standards.ieee.org/standards-ra-web/pub/view.html#registries
FYI, my Pico W has a 28:CD:C1 address.
You can fetch the most up to date MA-L data from the IEEE with this one-liner:
curl -sSL https://standards-oui.ieee.org/oui/oui.txt \ | grep -i '[(]hex[)].*raspberry' \ | sort 28-CD-C1 (hex) Raspberry Pi Trading Ltd 2C-CF-67 (hex) Raspberry Pi (Trading) Ltd B8-27-EB (hex) Raspberry Pi Foundation D8-3A-DD (hex) Raspberry Pi Trading Ltd DC-A6-32 (hex) Raspberry Pi Trading Ltd E4-5F-01 (hex) Raspberry Pi Trading Ltd You can fetch the most up to date CID data from the IEEE with this one-liner:
curl -sSL https://standards-oui.ieee.org/cid/cid.txt \ | grep -i '[(]hex[)].*raspberry' \ | sort 3A-35-41 (hex) Raspberry Pi (Trading) Ltd 
28:CD:C1 and D8:3A:DD are now registered to Raspberry Pi Trading Ltd, per the IEEE OUI database. 3A:35:41 is a CID (Company ID) maclookup.app/macaddress/3a3541 The best resource to find the most current OUI assignments is from the MAC Address Block Large (MA-L) Public Listing at the IEEE -- http://standards.ieee.org/develop/regauth/oui/public.html.
A complete list of OUI assignments is compiled daily and is available at http://standards-oui.ieee.org/oui.txt.
According to this list there is a single OUI/MA-L assignment for the Raspberry Pi Foundation:
> B8-27-EB (hex) Raspberry Pi Foundation > B827EB (base 16) Raspberry Pi Foundation > Mitchell Wood House > Caldecote Cambridgeshire CB23 7NU > UNITED KINGDOM 
B8-27-EB on a Raspberry Pi 3 Model B To elaborate the answer from @cachius: the OUI has changed from
B8-27-EB (hex) Raspberry Pi Foundation B827EB (base 16) Raspberry Pi Foundation Mitchell Wood House Caldecote Cambridgeshire CB23 7NU UNITED KINGDOM to
DC-A6-32 (hex) Raspberry Pi Trading Ltd DCA632 (base 16) Raspberry Pi Trading Ltd Maurice Wilkes Building, Cowley Road Cambridge CB4 0DS GB according to http://standards-oui.ieee.org/oui.txt.
The Raspberry Pi 4 Model B already has the new OUI.
Add also
E4-5F-01 (hex) Raspberry Pi Trading Ltd E45F01 (base 16) Raspberry Pi Trading Ltd Maurice Wilkes Building, Cowley Road Cambridge CB4 0DS GB According to the wikipedia article you linked,
In MAC addresses, the OUI is combined with a 24-bit number (assigned by the owner or 'assignee' of the OUI) to form the address. The first three octets of the address are the OUI.
So this is pretty straightforward; the first half of a MAC address is the OUI and the second half is arbitrary.
Lo and behold, on the four pis I have here (two B's, one made in China, one B+, and one pi 2), the first three octets are:
b8 27 eb Doing a bit of random searching online ("raspberry pi MAC address") also turns up this OUI.
The below script can be used to find any vendor by Mac: Raspberry Pi or otherwise.
Just supply the vendor's name as it's specified in the IEEE's MAC DB:
"http://standards-oui.ieee.org/oui.txt"
in the variable "VENDOR" and of course replace the echo's in the conditional expression with something useful.
In its' present form it's meant to execute locally on a host, but the script could be adapted quite easily I imagine.
#!/bin/bash #set -x VENDOR='Raspberry Pi' OUI=`ip addr list | grep -w link | awk '{print $2}' | grep -P "^(?!00:00:00)"| grep -P "^(?!fe80)" | tr -d ":" | head -c 6` if [[ $( curl -sS "http://standards-oui.ieee.org/oui.txt" | grep -i "$OUI" | grep -o "$VENDOR" ) = 'Raspberry Pi' ]]; then echo "This is a Pi" else echo "This is NOT a Pi" fi It is worth noticing, that the companyname (in the oui.txt) changed with the new Pi4:
B8-27-EB (hex) Raspberry Pi Foundation DC-A6-32 (hex) Raspberry Pi Trading Ltd.It is worth noting that the MAC-48 number applies to the Network Interface and not the Host device and thus the B8:27:EB applies only to the wired EtherNet interface on older Raspberry Pi devices that do not have a built-in Broadcomm device providing Wireless networking!
A WiFi USB dongle added to give an RPi wireless-networking where it does not have it natively will have a OUI that is specific (one hopes) to the manufacturer - though there are now utilities to fake the whole MAC number for good (or evil) purposes. This is important should you be trying to find older RPis wirelessly and wondering why you cannot see MACs beginning with that value...
To add to what @Ingo said, they actually have a third OUI now: E4-5F-01
Not sure why that happened either, but I have hardware with a MAC with that OUI.
I'd have commented that, but don't have enough reputation.
In my very personal case.
recovery b8:27:eb:c2:37:9d OUI search
b8:27:eb
Find Results B8:27:EB Raspberry Pi Foundation
Both the Ethernet and the Wifi on the RPi3 (Raspberry Pi 3) have are prefixed b8:27:eb.
pi@raspberrypi:~ $ ifconfig | egrep "(ether|flags)" eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 ether b8:27:eb:ad:78:e4 txqueuelen 1000 (Ethernet) lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 wlan0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 ether b8:27:eb:f8:2d:b1 txqueuelen 1000 (Ethernet) The Raspberry Pi 4 has
DC:A6:32:xx:xx:xx (Raspberry Pi Trading) according to the Raspberry Pi Forums.
confirming a reception of an rpi in the mac range D8:3A:DD, with 4GB RAM.
cannot upvote yet, otherwise I would have done that instead.
