Problem with DHCP during boot - Devuan Beowulf

Simon Hobson simon at
Wed Jul 15 21:10:59 UTC 2020

I think this is more an OS question than a DHCP one, but I'm hoping someone here might have an idea.

I've got a VM running Devuan Beowulf that was upgraded from Debian Wheezy (via Devuan Ascii). Devuan being "Debian without SystemD".

The problem I have is that it keeps getting different IP addresses during boot, never the one the DHCP server is configured (reserved lease) to give it. On tracing packets, I see that it's using a different DUID value during boot than it uses if I manually take the interface down and back up (ifdown eth0;ifup eth0 when the system is running). Also, during boot I see the message "Configuring network interfaces...ifup: interface eth0 already configured".

This suggests to me that something is bringing up the interface early during boot, using a different or non-existant DHCP Client config. I suspect non-existant since the address leased changes every boot which suggests a different DUID. I just can't see how/where the interface is being brought up .

From my packet trace, I'm seeing the client sending :
   Option: (61) Client identifier
       Length: 19
       IAID: 3e10c4f2
       DUID type: link-layer address plus time (1)
       Hardware type: Ethernet (1)
       Time: 648121466
       Link-layer address: 02:16:3e:10:c4:f2

Time: 648121466 is what I consistently get bringing up the interface manually *after* booting. During boot I get different Time values - so the DUID is different, so the DHCP server treats it as a different client.
Looking at two different packet traces, I see values of 648143408 and 648121466, puts them about 75 minutes apart which ties in with the timestamps of my packet capture files.

Can anyone give me any hint as to what is bringing up the network before it is supposed to be ?


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