Changing ehernet link level address and uuidgen command

[hishnik]

Hello.

> ifconfig re0
re0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
    options=8209b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,WOL_MAGIC,LINKSTATE>
    ether 1c:87:2c:77:f4:c7
    inet 192.168.34.24 netmask 0xffffff00 broadcast 192.168.34.255
    media: Ethernet autoselect (1000baseT <full-duplex>)
    status: active
    nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>

If I change link level address on ethernet interface, for example:
ifconfig re0 link 1c:87:2c:aa:bb:cc
then i get:

> ifconfig re0                       
re0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
    options=8209b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,WOL_MAGIC,LINKSTATE>
    ether 1c:87:2c:aa:bb:cc
    hwaddr 1c:87:2c:77:f4:c7
    inet 192.168.34.24 netmask 0xffffff00 broadcast 192.168.34.255
    media: Ethernet autoselect (1000baseT <full-duplex>)
    status: active
    nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>

, but when i run:

> uuidgen                  
276dc33f-9553-11ec-94e7-1c872c77f4c7

.

It uses hardware address attribute "hwaddr" for UUID generation, not link level "ether".

Can we change this behaviour?
Is it possible to change hwaddr?

 

[covacat]

kernel uuidgen data is supplied by the network device driver when it is attached
so even if you can change hwaddr would have no effect

 

[hishnik]

Thank you for paying attention to my question.

kernel uuidgen data is supplied by the network device driver when it is attached

So, is it possible to change this data value (which uuidgen uses for generating UUID), for example with `sysctl` or somehow?

so even if you can change hwaddr would have no effect

Can I instruct network card driver to forcibly change value of hwaddr attribute, `ifconfig` shows?