assigning MACs to Sun NICs

[Han Lievens <hanl_(_at_)_bonch_(_dot_)_org>]

Hello,
I'm trying to use a Sparc20 w/ 3 sbus le nics as a firewall using 2.6 running ipf & bridging.
The OS crashes & takes me to dbd when I have both bridging & ipf enabled.
So I figured (w/ Art's help) that maybe I needed to set the EEPROM local-mac-address value to TRUE.
The MACs on all 3 nics are still the same, so I'm trying to assign my own MACs.
Now I'm having difficulty assigning the MACs.
When I do an ifconfig le1 ether, no matter what MAC value I use, Bad Value is returned.
I see no mention of the ether option in the ifconfig manpages.
I know "ifconfig  le0 ether xx:xx:xx:xx:xx:xx" can be used on Solaris.  Is there something I'm missing for OpenBSD ?
Do I really need to assign MACs to these interfaces in order to use bridging & ipf ?
Pertinent dmesg :

OpenBSD 2.6 (GENERIC) #287: Thu Oct 21 23:31:48 MDT 1999
deraadt_(_at_)_sun4m_(_dot_)_openbsd_(_dot_)_org:/usr/src/sys/arch/sparc/compile/GENERIC
iommu0 at mainbus0 ioaddr 0xe0000000: version 0x3/0x1, page-size 4096, range 64MB
sbus0 at iommu0: clock = 25 MHz
ledma0 at sbus0 slot 15 offset 0x400010: rev 2
le0 at ledma0 offset 0xc00000 pri 6: address 08:00:20:88:ff:68
le0: 16 receive buffers, 4 transmit buffers
lebuffer0 at sbus0 slot 0 offset 0x40000: 128K memory
le1 at lebuffer0 offset 0x60000 pri 7: address 08:00:20:88:ff:68
le1: 64 receive buffers, 16 transmit buffers
lebuffer1 at sbus0 slot 2 offset 0x40000: 128K memory
le2 at lebuffer1 offset 0x60000 pri 7: address 08:00:20:88:ff:68
le2: 64 receive buffers, 16 transmit buffers

Thanks for your help, Han.