[Linuxptp-users] I am trying to get PTP to work over an interesting network topology.

[Robb <rba...@gm...>]

I am having trouble getting PTP to work over a network bridge br0.

They are both CentOS 6.5 machines with 2.6.32-504.8.1.el6.x86_64, and running
linuxptp-1.3-1.el6.x86_64.

Each machine has two NICS.
eth0 [e1000e] Intel I217-LM (rev 05)
eth1 [igb]    Intel I210 (rev 03)


Here is the topology:

Machine1:
br0  192.168.2.1
  -bridges both wlan0 and eth1
  -has a dhcp server running on it.
eth0 192.168.1.17
  -gets it's ip from LAN
eth1
  -connected to eth0 on machine 2
wlan0
  -provides a Wifi Access point to the 192.168.2.* network

Machine2:
eth0 192.168.2.7
  -connected directly to eth1 on Machine1
  -gets its IP from Machine1's dhcp server
eth1 down


What I would like to do is do the following:
[Machine1 ~]# ptp4l -i eth1 -m
[Machine2 ~]# ptp4l -i eth0 -m

I changed the default route on Machine1 and can visually see in iptraf-ng that
the ptp packets are going to 192.168.2.*  and while the machine happily detects
master and slave at first, nothing else happens, the Machine2 assumes grand
master role..

[Machine1 ~]# ptp4l -i eth1 -m
ptp4l[2847.269]: selected /dev/ptp1 as PTP clock
ptp4l[2847.271]: driver changed our HWTSTAMP options
ptp4l[2847.271]: tx_type   1 not 1
ptp4l[2847.271]: rx_filter 1 not 12
ptp4l[2847.271]: port 1: INITIALIZING to LISTENING on INITIALIZE
ptp4l[2847.271]: port 0: INITIALIZING to LISTENING on INITIALIZE
ptp4l[2853.271]: port 1: LISTENING to MASTER on ANNOUNCE_RECEIPT_TIMEOUT_EXPIRES
ptp4l[2853.271]: selected best master clock d05099.fffe.09aaf4
ptp4l[2853.271]: assuming the grand master role

[Machine2 ~]# ptp4l -i eth0 -m
ptp4l[966.068]: selected /dev/ptp0 as PTP clock
ptp4l[966.075]: port 1: INITIALIZING to LISTENING on INITIALIZE
ptp4l[966.075]: port 0: INITIALIZING to LISTENING on INITIALIZE
ptp4l[967.756]: port 1: new foreign master d05099.fffe.09aaf4-1
ptp4l[971.756]: selected best master clock d05099.fffe.09aaf4
ptp4l[971.757]: port 1: LISTENING to UNCALIBRATED on RS_SLAVE
ptp4l[1191.765]: port 1: UNCALIBRATED to MASTER on
ANNOUNCE_RECEIPT_TIMEOUT_EXPIRES
ptp4l[1191.765]: selected best master clock d05099.fffe.5df7e6
ptp4l[1191.765]: assuming the grand master role


iptables is down on both machines.
Works fine (as expected) with NO bridge when Machine1:eth1 192.168.2.1 (master)
and Machine2:eth0 192.168.2.7 (slave).

So what is the bridge messing up? And is there a way to fix it?

I would appreciate any insight I can get.  Even if it is a suggestion for a
better topology.

Thanks,

Robb