Re: dhcpcd doesn't remove alias address on interface-down?

[Roy Marples <roy%marples.name@localhost>]

Hi Paul

On 2015-07-31 03:02, Paul Goyette wrote:
> On Fri, 31 Jul 2015, Roy Marples wrote:
>
> > This is not normal or expected!
> > I'm very bogged down in my personal life atm, but it would help if you 
> > could capture a tcpdump of the bootp messages on the client whilst 
> > rebooting the router.
> > dhcpcd output with the debug directive in dhcpcd.conf would be of 
> > benefit as well whilst the reboot happens.
>
> I can get the tcpdump info with
>
> 	tcpdump -i re0 -s 2000 port bootps or port bootpc
>
> But how can I capture the dhcpcd output?  Even with -w it forks to the
> background as soon as it has an address, so it doesn't log any further
> info in stdout/stderr

What I do is this

dhcpcd -dB re0

dhcpcd will also log everything to syslog

I suspect it goes like this.

dhcpcd - what IP do I use?
router - ABCD
dhcpcd - using ABCD
dhcpcd - Renewing ABCD
router - OK
router reboots here
dhcpcd - Renewing ABCD
router - EFGH
dhcpcd - using EFGH

what should have happened is the router issuing a NAK just before EFGH, 
but I suspect it's not and just changing the IP address given.
Now, dhcpcd *should* do the right thing, but I suspect it isn't.


> In any case, the situation might be more complicated.  I just
> rebooted, and got one of the earlier addresses (192.168.1.3) and
> dhcpcd reported
>
> 	re0: IP address 192.168.1.3/24 already exists
>
> I don't know why, but all those addresses and aliases seem to have
> survived the dhcpcd restart.

dhcpcd doesn't remove addresses it doesn't know about ..... or as 
accidentally forgotten about, which is the issue we are talking about.

> So I guess I need to find some time when I can conduct some more
> detailed experiments.  :)

Ah time.
As the years go by it's such a valuable and scarce resource.

Roy