Re: IPv4 networking problem after dist-upgrade

[Oleg <gandalf+debian@stillroot.org>]

Hi again!

On Wed, Oct 06, 2021 at 06:02:40PM +0200, Oleg wrote:
> > ip link show
> 
> $ > ip l sh
> <snip>...</snip>
> 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1492 qdisc pfifo_fast master direct0 state UP mode DEFAULT group default qlen 1000
>     link/ether 54:04:a6:a0:77:de brd ff:ff:ff:ff:ff:ff
> 3: direct0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1492 qdisc noqueue state UP mode DEFAULT group default qlen 1000
>     link/ether 32:95:e2:a2:8e:0e brd ff:ff:ff:ff:ff:ff
> <snip>...</snip>

Apparently the error originated from the deviating MAC address of physical
interface and bridge. After I configured direct0 to have the same MAC address
as eth0 IPv4 started to work as expected again.

I assume that some security/anti-spoofing mechanism on the network/gateway
side rejected the "new" MAC address that has probably changed during the
upgrade.

Cheers
Oleg