Error : (init) failed to join the multicast group

[Jose Manuel]

Hi Folks,

i'm using ptpd2 v2.3.1 and can synchronize clocks between my Vmware and my slave in Unicast.
When i try multicast gives me that error:
(init) failed to join the multicast group (strerror: No such file or directory)

Im using an custom kernel version 4.11.0-rc5.
I thhink probably the problem is this erros in my logging dmesg:
"
Starting ptpd2: random: crng init done
Configuration error: option "ptpengine:interface" is required
Warning: Unicast negotiation can only be used with unicast transmission

There are errors in the configuration - see previous messages
PTPDv2 startup failed
FAILED "

However unicast syncs Ok.

My full boot up message are :
http://pasted.co/30eed731

My error joing multicast is:
http://pasted.co/b36dfb37

Anyidea what can be?
Regards

Best Regards from Portugal,

[Jose Manuel]

Probably i have the ptpd.conf by default (and my eth0 is not defined) so gives me the error i described, im reading this:

Anyone know where i can define the config file? im using buildroot and this way:
https://gist.github.com/mhaberler/f4809ed2e465912d3534

it should work for ptpd2 or only for ptpd?

shoud i rename the file for etc/default/ptpd2 instead of etc/default/ptpd ?

Regards,

[Jose Manuel]

I've got these errors too:

// # ptpd2 -C -m -i eth0

2017-04-20 15:37:02.660701 ptpd2[233].startup (info) () Configuration OK
2017-04-20 15:37:02.660827 ptpd2[233].startup (info) () Successfully acquired lock on /var/run/ptpd2.lock
2017-04-20 15:37:02.660883 ptpd2[233].startup (notice) () PTPDv2 started successfully on eth0 using "masterslave" preset (PID 233)
2017-04-20 15:37:02.660897 ptpd2[233].startup (info) () TimingService.PTP0: PTP service init
2017-04-20 15:37:02.661040 ptpd2[233].eth0 (error) (init) failed to join the multicast group (strerror: No such file or directory)
2017-04-20 15:37:02.661053 ptpd2[233].eth0 (error) (init) Failed to initialize network
2017-04-20 15:37:02.661063 ptpd2[233].eth0 (error) (flt) PTPd init failed - will retry in 10 seconds

[Jose Manuel]

Now works. just doned:

echo 10 >/proc/sys/net/ipv4/igmp_max_memberships

But where i can define my .conf file to when ptpd2 starts init with my .conf?

Regards