Hi everybody,
This post is more or less a follow-up to yesterday's post about creating
a bridge for KVM, which has brought up an interesting problem. I think
this deserves a distinct post on its own.
This morning I tried a little experiment. I installed a minimal
AlmaLinux 9.7 on a sandbox PC. And then I created a network bridge using
nmtui, because RHEL and clones default to NetworkManager, even on
minimal systems. So here's what I get:
# ip addr
...
2: enp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> ...
link/ether b0:83:fe:90:4d:64 brd ff:ff:ff:ff:ff:ff
3: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> ...
link/ether b0:83:fe:90:4d:64 brd ff:ff:ff:ff:ff:ff
inet 192.168.2.3/24 brd 192.168.2.255 scope global dynamic
noprefixroute br0
valid_lft 86379sec preferred_lft 86379sec
inet6 fe80::b283:feff:fe90:4d64/64 scope link
valid_lft forever preferred_lft forever
Notice how enp3s0 and br0 *have the same MAC address* ? <== IMPORTANT
I tried this again with AlmaLinux 10.1, with exactly the same result.
Same MAC address for enp3s0 and br0. Which is sort of the expected
behaviour. <== IMPORTANT
Now I installed a minimal Debian system on this same PC. Here's the
default /etc/network/interfaces as configured by the installer:
allow-hotplug enp3s0
iface enp3s0 inet dhcp
I created a bridge by replacing the above stanza with this:
auto enp3s0
iface enp3s0 inet manual
auto br0
iface br0 inet dhcp
bridge_ports enp3s0
I rebooted and had a bridge OK, but with a different IP address, since
now the br0 MAC address IS DISTINCT from the enp3s0 MAC address:
# ip addr
2: enp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> ...
link/ether b0:83:fe:90:4d:64 brd ff:ff:ff:ff:ff:ff
altname enxb083fe904d64
3: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> ...
link/ether f2:5c:e4:0b:e7:30 brd ff:ff:ff:ff:ff:ff
inet 192.168.2.191/24 brd 192.168.2.255 scope global dynamic
noprefixroute br0
valid_lft 86242sec preferred_lft 75442sec
inet6 fe80::9a0d:650b:e751:6e37/64 scope link
valid_lft forever preferred_lft forever
So here's my question. I'd like my br0 to have the same MAC address as
my enp3s0 without having to jump through burning loops.
Any suggestions ?
Niki
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