> On 11.10.2021, at 17:22, Simon Matter <simon.matter at invoca.ch> wrote: > > Hi, > >> On Mon, 11 Oct 2021, José María Terry Jiménez wrote: >> >>> El 11/10/21 a las 13:00, Tom Yates escribió: >>>> On Mon, 11 Oct 2021, José María Terry Jiménez wrote: >>>> >>>>> Hello >>>>> >>>>> Perhaps the solution is this: >>>>> >>>>> https://access.redhat.com/solutions/70215HWADDR= >>>> >>>> thanks, but either that link is broken, or the site requires a login, >>>> as i >>>> can't see anything and get redirected to a general search page. could >>>> i >>>> trouble you to check the link? >>>> >>>> >>> Uh oh! Some copypaste at the end >>> >>> Is this one >>> >>> https://access.redhat.com/solutions/70215 >> >> thank you very much for the suggestion! sadly, this has not worked. >> > > Are you even sure it's NetworkManager messing with your MAC addresses? I > have no idea why NM should ever mess with MAC addresses on a server and I > don't expect NM is doing so. > > I have another idea: Seems this is on a SuperMicro server, can it be that > the box in question has a shared lights out management, sharing the > management ethernet port with the first LAN port? If so, can it be that > the management port is not configured properly and does try to DHCP an > IPv4 address? If you don't need the management stuff then you may try to > simply disable it to get rid of the mess. Yeah, there is a default setting in the Firmware of “failover” which means “use dedicated IPMI port if connected otherwise use shared LAN port” This is under IPMI -> BMC Network Configuration see also https://serverfault.com/questions/361940/configuring-supermicro-ipmi-to-use-one-of-the-lan-interfaces-instead-of-the-ipmi But, is this kind of traffic supposed to be visible to the linux kernel? (or was the tcpdump made on another machine?) Best Regards, Markus