Changing MAC address

[Beanybop]

Hi
I have recently tried setting up a static IP address for my pi. I have reserved an IP on my router for the pi. However after rebooting the pi I went to the client list of my router and it showed a differant MAC address wich meant the router was reserving an IP for the wrong device. I am wondering what might cause my MAC address to change, according to everything I have read it shouldn't.
Thanks for your help.

[B.Goode]

what might cause my MAC address to change, according to everything I have read it shouldn't.

In general that's correct, although there are ways of overriding that behaviour if you wish.

More details needed for a helpful reply.

What model RPi; what Operating System.

What was the original 'wrong' MAC address? What is it now? Did you swap from cabled to WiFi networking? Did you try a different USB WiFi adapter?

[Beanybop]

I am using a raspberry pi model 3 B so I'm using integrated wifi, not cable. On the pi I'm using Raspian PIXEL.

[Beanybop]

I have been on the same wifi network the hole time.

[RaTTuS]

what does ifconfig show on the RPI

[Beanybop]

Ifconfig returend the following:

eth0 Link encap:Ethernet HWaddr b8:27:ebc6:56
inet6 addr: fe80::3da7:5dfb:bfa9:f78/64 Scope:Link
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:225 errors:0 dropped:0 overruns:0 frame:0
TX packets:225 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:18316 (17.8 KiB) TX bytes:18316 (17.8 KiB)

wlan0 Link encap:Ethernet HWaddr b8:27:eb:fe:93:03
inet addr:192.168.0.197 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::e2a0:b672:e7df:65c2/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:48 errors:0 dropped:0 overruns:0 frame:0
TX packets:57 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:7341 (7.1 KiB) TX bytes:10167 (9.9 KiB)

[Beanybop]

Later I rebooted the pi and the MAC address changed again.

[DirkS]

Later I rebooted the pi and the MAC address changed again.

Do you mean one of the MAC addresses starting with b8:27:eb ?

[RaTTuS]

wlan0 Link encap:Ethernet HWaddr b8:27:eb:fe:93:03
inet addr:192.168.0.197 Bcast:192.168.0.255 Mask:255.255.255.0

what is changing

[DougieLawson]

eth0 Link encap:Ethernet HWaddr b8:27:ebc6:56
inet6 addr: fe80::3da7:5dfb:bfa9:f78/64 Scope:Link

wlan0 Link encap:Ethernet HWaddr b8:27:eb:fe:93:03
inet addr:192.168.0.197 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::e2a0:b672:e7df:65c2/64 Scope:Link

Do you mean the fe80::/64 link local IPv6 address?

That will change because you've got

Code: Select all

slaac private

in /etc/dhcpcd.conf. If you'd like a static link local address based on EUI-64 created from your MAC-48 addresses then change dhcpcd.conf to

Code: Select all

#slaac private
slaac hardware

and reboot.

[Beanybop]

I meant this address: b8:27:eb:fe:93:03.

[DougieLawson]

I meant this address: b8:27:eb:fe:93:03.

That can't change, it's burned into the hardware.

[B.Goode]

I meant this address: b8:27:eb:fe:93:03.

If this is the third different address you have seen, what were the previous values?

[Beanybop]

That can't change, it's burned into the hardware.

When I use ifconfig I can see that the address doesn't change however when I go on my router I can clearly see the MAC address changes when the pi is rebooted. Is this a problem with my pi or router?

[DougieLawson]

It's your router that is getting things mixed up.