dhcpcd-discuss

Hi Roy

I think I may have sussed the time stamp changing. In some of my tests 
searching for stability for the ipv6 address I had a duid option in an 
interface stanza as well as in the global conf. I wonder if that would 
cause it?

This system worked fine for a number of years with just a static ip6 
address in the interface stanza. Until a couple of weeks ago when a power 
surge cause a reboot. Then it "lost" its normal ipv6 address. I think this 
was caused by an update to the router firmware, and the presence of 
infinite static lease in the router for the normal ipv6 address.

In my struggles to get things working again at one point I had that extra 
duid option in.

My current config looks like

duid
interface eth0
iaid 9

The dhcpcd.duid file exists and contains my truncated type 2 duid.

It looks like the logic that processes the duid option detects my the 
presence of my type 2 duid and does not overwrite the file on every 
restart. In that case would it be safer to comment out the global duid 
option (the default), or is it required to enable other parts of the duid 
functionality?

Roger

On 14 March 2019 00:34:56 Roy Marples <roy@xxxxxxxxxxxx> wrote:

> Hi Roger
>
> On 13/03/2019 17:24, Roger James wrote:
> > Running dhcpcd version 1:6.11.5-1+rpt7 on debian. I see the DUID-LLT
> > generated by dhcpcd and stored dhcpcd.duid is being updated with a new
> > timestamp every time it is sent out for example in a solicit. Surely
> > this is contrary to RFC6355.
> >
> >
> > "DUIDs are intended to remain constant over time, so that they can be
> >    used as permanent identifiers for a device. In the case of DUID-
> >    LLTs, they are intended to be generated once, stored in stable
> >    storage, and reused from that point forward."
> >
> >
> > Is this intentional?
>
> Certainly not from dhcpcd.
> It's not intentional if the case.
>
> > Also if the dhcp.duid file is hand edited and a DUID-UUID is inserted,
> > then then the UUID part of the DUID is truncated to 8 bytes when it is
> > used.
> >
> >
> > This makes it difficult to use dhcpcd to assign static dhcpv6 leases.
>
> Maybe this is the cause of the former?
> Would you mind sharing a duid file which exhibits this?
>
> Roy