PTPv2

Global Time PTPv2

FMADIO capture systems support PTPv2 using the linux PTP open source project. ( http://linuxptp.sourceforge.net/ )  running only on the 10G management interface. 1G links are supported using 1G RJ45 SFP transceiver.

Step 1) Configure timming to use PTPv2

Enabling PTPv2 via GUI is as follows

Step 2) Use baremetal NIC on the PTPv2 interface

In addition the 10G Bridged networking config must be disabled. As LinuxPTP must run directly on the bare metal NIC to accurately hardware timestamp the incoming packets.

Please edit the file

/opt/fmadio/etc/60-persistent-ethernet.rules

Change the "phy10" values as shown below to "man10"

Changed to "man10" as follows

Step 3) Reboot

System must be rebooted for the above to take effect.

PTPv2 VLAN Interface

In some environments PTPv2 is run on its own dedicated VLAN interface.

Step 1) Set the VLAN

To enable this update the configuration file

/opt/fmadio/etc/time.lua

Specifically setting the VLANID as follows, in the below example its set to VLANID "123"

["PTP"] =
{
    ["Master0"] = "",
    ["Master1"] = "",
    ["Master2"] = "",
    ["Master3"] = "",
    ["UpdateRate"] = "",
    ["VLANID"] = "123",
    ["Interface"] = "man10",
},

After editing save and confirm the file syntax is correct, ensure there are no syntax or parse errors. The  correct output is shown below.

fmadio@fmadio20n40v3-364:~$ fmadiolua /opt/fmadio/etc/time.lua
fmad fmadlua Aug 10 2021
failed to open self? [fmadiolua]
loading filename [/opt/fmadio/etc/time.lua]
done 0.000051Sec 0.000001Min
fmadio@fmadio20n40v3-364:~$

Step 2) Reboot or restart linuxptp daemon

Either reboot the system, or kill all ptp processes (e.g. sudo killall ptp4l; sudo killall phc2sys)

Step 3) Confirm network interface is created

On reboot a man10.123  VLAN interface that matches the set VLANID should be populated as follows

fmadio@fmadio20n40v3-364:~$ ifconfig man10.123
man10.123 Link encap:Ethernet  HWaddr 18:C0:4D:17:7A:4E
          BROADCAST MULTICAST  MTU:9200  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

fmadio@fmadio20n40v3-364:~$

Step 4) Confirm linux4ptp daemons are binded

And the linux ptp daemon should have binded  to the newly created instance as follows

fmadio@fmadio20n40v3-364:~$ ps aux |grep ptp4l
64727 root     /opt/fmadio/bin/ptp4l -4 -H -i man10.123 -m -s
fmadio@fmadio20n40v3-364:~$

And the PHC interface also

fmadio@fmadio20n40v3-364:~$ ps aux |grep phc2sys
64729 root     /opt/fmadio/bin/phc2sys -s man10.123 -c CLOCK_REALTIME -w -m -P 0.7 -I 0.3
fmadio@fmadio20n40v3-364:~$

PTPv2 on Second 10G Port

The above config assumes PTPv2 is running on the primary 10G management port. There is not requirement for using the primary port, instead the 2nd 10G management port can also be used. Below are the differences required

Step 1) n the udev rules phy10 -> phy11 -> man11

Use phy11 interface

Rename to man11

Step 2) Set the IP address of man11

man11 needs to be configured with an IP address, either editing  network config file directly

/opt/fmadio/etc/network.lua

or using the fmadiocli command line utility

Step 3) Specify man11 in the ptp config per below

["PTP"] =
{
    ["Master0"] = "",
    ["Master1"] = "",
    ["Master2"] = "",
    ["Master3"] = "",
    ["UpdateRate"] = "",
    ["VLANID"] = nil,
    ["Interface"] = "man11",
},

Step 4) Finished

PTP on the Second 1G RJ45 Port

PTPv2 can be run on the 2nd 1G management interface, as it supports both a PHC clock and IEE1588 hardware timestamping.

NOTE: PTPv2 can not be run on the primary/first 1G interface as this is a software bridged interface and does not support hardware timestamping.

Step 1) Configure the udev rules as follows

/opt/fmadio/etc/60-persistent-ethernet.rules

Set the phy1 interface renamed to man1 as shown below

After update looks like below

Step 2) Set the IP address of man1

man1 needs to be configured with an IP address that the PTP master can reach. Set the network information either editing  network config file directly

/opt/fmadio/etc/network.lua

or using the fmadiocli command line utility

Step 3) Specify man1 in the ptp config per below

["PTP"] =
{
    ["Master0"] = "",
    ["Master1"] = "",
    ["Master2"] = "",
    ["Master3"] = "",
    ["UpdateRate"] = "",
    ["VLANID"] = nil,
    ["Interface"] = "man1",
},

Step 4) Reboot

A reboot is required to change the UDEV rules making man1 a physical bare metal interface. Upon reboot PTP GrandMaster should be visible on the dashboard Clock table.

Custom LinuxPTP Config

FMADIO system use the standard LinuxPTP project for time synchronization

https://linuxptp.sourceforge.net/

As such the PTP configuration is highly customizable. For example Broadcast environments use a non standard domain and update rate. FMADIO support this by using a custom LinuxPTP configuration file.

Custom config file can be located below

/opt/fmadio/etc/ptp4l.conf

If this file is present the system will use it when starting the application ptp4l.

NOTE: if changing the PTPv2 ethernet interface in the ptp4l.conf its also required to change it in the general /opt/fmadio/etc/time.lua configuration file (for the PHC setting)

After creating or editing the file, need to stop ptp4l as follows

After creating or editing the file, need to stop ptp4l as follows

// Some code
sudo killall ptp4l
sudo killall phc2sys

The system will then automatically start it on a 60sec timer.

Logfiles for debugging can be found in

/mnt/store0/log/ptp_ptp4l.log
/mnt/store0/log/ptp_phc2sys.log

Layer2 PTPv2 Configuration

By default Linux4ptp will run in a layer 3 IP multicast / Unicast mode, per the man page

network_transport

Select the network transport. Possible values are UDPv4, UDPv6 and L2. The default is UDPv4.

In some configurations that is not ideal, instead a pure layer 2 mode is the preferred transport.

To enable Layer2 create the file

/opt/fmadio/etc/ptp4l.conf

The configuration (using man10 as the interface) is shown below

[global]
# Automatically select the delay mechanism (E2E or P2P)
delay_mechanism auto

# Use IEEE 802.3 (Ethernet) as the network transport
network_transport L2

# use the man10 interface (assuming the 60-udev rules have been updated)
[man10]

Save the file and restart ptp4linux using

sudo killall ptp4l

Debug

If the system is not synchronizing correctly the following log files may help debug the problem

/mnt/store0/log/ptp_ptp4l.log
/mnt/store0/log/ptp_phc2sys.log

In addition there are log files showing the startup process which can be helpful.

/mnt/store0/log/time_ptp.stdouterr_YYYYMMMDD

General System FPGA clock synchronization log file is located below, this is more for FPGA timestamp issues than configuration of PTPv2

/mnt/store0/log/fnic_clock.cur

Debug PTP Layer3

PTP can be run in Layer 3 mode using UDP multicast as the transport mode, below is a guide on debuging ptp4l UDP Layer3 setup

Confirm the interface does not have VLAN tags

sudo tcpdump -i phy11 -nn -T ptp not vlan

Expected output similar to below

Confirm Announce Message

Confirm Announce message are being sent, at roughly what frequency, every 1sec or every 30sec

 sudo tcpdump -i phy11 -nn -T ptp not vlan | grep announce

Expected output is list of announce only messages

Confirm the announce frequency matches the ptp4l.conf  (default is 30sec) per below

announceReceiptTimeout  30    
logAnnounceInterval     0 

Confirm Sync Message

Confirm the Sync message is being received on the management interface, at the approximate rate of the configuration file

 sudo tcpdump -i man11 -nn -T ptp not vlan | grep sync

Example output, note the timestamp of each message is about 1 sec apart

fmadio@fmadio200v4-636:~$  sudo tcpdump -i man11 -nn -T ptp not vlan | grep sync

12:02:35.408340922 IP 192.168.2.5.319 > 224.0.1.129.319: PTPv2, v1 compat : no, msg type : sync msg, length : 44, domain : 4, reserved1 : 0, Flags [none], NS correction : 1807, sub NS correction : 1, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 1, seq id : 34803, control : 0 (Sync), log message interval : 0, originTimeStamp : 1767591896 seconds, 220502350 nanoseconds
12:02:36.408338517 IP 192.168.2.5.319 > 224.0.1.129.319: PTPv2, v1 compat : no, msg type : sync msg, length : 44, domain : 4, reserved1 : 0, Flags [none], NS correction : 1815, sub NS correction : 1, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 1, seq id : 34804, control : 0 (Sync), log message interval : 0, originTimeStamp : 1767591897 seconds, 220502349 nanoseconds
12:02:37.408335343 IP 192.168.2.5.319 > 224.0.1.129.319: PTPv2, v1 compat : no, msg type : sync msg, length : 44, domain : 4, reserved1 : 0, Flags [none], NS correction : 1759, sub NS correction : 0, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 1, seq id : 34805, control : 0 (Sync), log message interval : 0, originTimeStamp : 1767591898 seconds, 220502349 nanoseconds
12:02:38.408335018 IP 192.168.2.5.319 > 224.0.1.129.319: PTPv2, v1 compat : no, msg type : sync msg, length : 44, domain : 4, reserved1 : 0, Flags [none], NS correction : 1763, sub NS correction : 0, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 1, seq id : 34806, control : 0 (Sync), log message interval : 0, originTimeStamp : 1767591899 seconds, 220502349 nanoseconds
12:02:39.408333363 IP 192.168.2.5.319 > 224.0.1.129.319: PTPv2, v1 compat : no, msg type : sync msg, length : 44, domain : 4, reserved1 : 0, Flags [none], NS correction : 1767, sub NS correction : 1, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 1, seq id : 34807, control : 0 (Sync), log message interval : 0, originTimeStamp : 1767591900 seconds, 220502350 nanoseconds
12:02:40.408332929 IP 192.168.2.5.319 > 224.0.1.129.319: PTPv2, v1 compat : no, msg type : sync msg, length : 44, domain : 4, reserved1 : 0, Flags [none], NS correction : 1839, sub NS correction : 1, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 1, seq id : 34808, control : 0 (Sync), log message interval : 0, originTimeStamp : 1767591901 seconds, 220502334 nanoseconds
12:02:41.408331564 IP 192.168.2.5.319 > 224.0.1.129.319: PTPv2, v1 compat : no, msg type : sync msg, length : 44, domain : 4, reserved1 : 0, Flags [none], NS correction : 1843, sub NS correction : 1, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 1, seq id : 34809, control : 0 (Sync), log message interval : 0, originTimeStamp : 1767591902 seconds, 220502333 nanoseconds
12:02:42.408332500 IP 192.168.2.5.319 > 224.0.1.129.319: PTPv2, v1 compat : no, msg type : sync msg, length : 44, domain : 4, reserved1 : 0, Flags [none], NS correction : 1787, sub NS correction : 0, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 1, seq id : 34810, control : 0 (Sync), log message interval : 0, originTimeStamp : 1767591903 seconds, 220502349 nanoseconds
12:02:43.408333446 IP 192.168.2.5.319 > 224.0.1.129.319: PTPv2, v1 compat : no, msg type : sync msg, length : 44, domain : 4, reserved1 : 0, Flags [none], NS correction : 1787, sub NS correction : 0, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 1, seq id : 34811, control : 0 (Sync), log message interval : 0, originTimeStamp : 1767591904 seconds, 220502349 nanoseconds

Confirm the frequency matches the ptp4l.conf

NOTE: logSyncInterval 0 = 1 sec, 1 = 2sec etc.

syncReceiptTimeout      30
logSyncInterval         0

Confirm Domain Number

confirm the domain number matches the config (in this case its using domain 4)

in ptp4l.conf the setting is

domainNumber 4  

Confirm Transport

Due to the IP/UDP encapsulation type

The p4p4l.conf setting is

network_transport UDPv4

Example tshark filter confirming the traffic received on the FMADIO management interface is correct

fmadio@fmadio200v4-636:~$ sudo tshark -i phy11 -Y ptp -T fields  -e eth.dst -e frame.protocols
Capturing on 'phy11'
01:00:5e:00:01:81       eth:ethertype:ip:udp:ptp
01:00:5e:00:01:81       eth:ethertype:ip:udp:ptp
01:00:5e:00:01:81       eth:ethertype:ip:udp:ptp
01:00:5e:00:01:81       eth:ethertype:ip:udp:ptp
01:00:5e:00:01:81       eth:ethertype:ip:udp:ptp
01:00:5e:00:01:81       eth:ethertype:ip:udp:ptp
01:00:5e:00:01:81       eth:ethertype:ip:udp:ptp
01:00:5e:00:01:81       eth:ethertype:ip:udp:ptp
01:00:5e:00:01:81       eth:ethertype:ip:udp:ptp
01:00:5e:00:01:81       eth:ethertype:ip:udp:ptp
01:00:5e:00:01:81       eth:ethertype:ip:udp:ptp

Confirm FMADIO egress

PTP requires a two way communication channel to calibrate the transport latency and jitter of the connection. Confirm the local system is egressing traffic to the PTP Master on the correct interface as follows

Confirm the PTP interface egressing using port 319, replace 192.168.2.215 with the IP address of management interface

 sudo tcpdump -i man11 -nn port 319 and src host 192.168.2.215 | grep "delay req"

Example output is

fmadio@fmadio200v4-636:~$ sudo tcpdump -i man11 -nn port 319 and src host 192.168.2.215 | grep "delay req" | head
tcpdump: verbose output suppressed, use -v[v]... for full protocol decode
listening on man11, link-type EN10MB (Ethernet), snapshot length 262144 bytes
11:30:00.112719899 IP 192.168.2.215.319 > 224.0.1.129.319: PTPv2, v1 compat : no, msg type : delay req msg, length : 44, domain : 4, reserved1 : 0, Flags [none], NS correction : 0, sub NS correction : 0, reserved2 : 0, clock identity : 0x40a6b7fffeda03c1, port id : 1, seq id : 28920, control : 1 (Delay_Req), log message interval : 127, originTimeStamp : 0 seconds, 0 nanoseconds
11:30:00.128033792 IP 192.168.2.215.319 > 224.0.1.129.319: PTPv2, v1 compat : no, msg type : delay req msg, length : 44, domain : 4, reserved1 : 0, Flags [none], NS correction : 0, sub NS correction : 0, reserved2 : 0, clock identity : 0x40a6b7fffeda03c1, port id : 1, seq id : 28921, control : 1 (Delay_Req), log message interval : 127, originTimeStamp : 0 seconds, 0 nanoseconds
11:30:00.141220632 IP 192.168.2.215.319 > 224.0.1.129.319: PTPv2, v1 compat : no, msg type : delay req msg, length : 44, domain : 4, reserved1 : 0, Flags [none], NS correction : 0, sub NS correction : 0, reserved2 : 0, clock identity : 0x40a6b7fffeda03c1, port id : 1, seq id : 28922, control : 1 (Delay_Req), log message interval : 127, originTimeStamp : 0 seconds, 0 nanoseconds
11:30:00.146497296 IP 192.168.2.215.319 > 224.0.1.129.319: PTPv2, v1 compat : no, msg type : delay req msg, length : 44, domain : 4, reserved1 : 0, Flags [none], NS correction : 0, sub NS correction : 0, reserved2 : 0, clock identity : 0x40a6b7fffeda03c1, port id : 1, seq id : 28923, control : 1 (Delay_Req), log message interval : 127, originTimeStamp : 0 seconds, 0 nanoseconds

Confirm PTP Master Response

This confirms PTP requests are going from the peer (the FMADIO) back to the PTP Master

Confirm the PTP Master is sending the delay request response back to the the peer (FMADIO)

Need to get the last 6 digits of the MAC address

fmadio@fmadio200v4-636:~$ ifconfig man11
man11     Link encap:Ethernet  HWaddr 40:A6:B7:DA:03:C1
          inet addr:192.168.2.215  Bcast:192.168.2.255  Mask:255.255.255.0
          inet6 addr: fe80::42a6:b7ff:feda:3c1/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:104277 errors:0 dropped:0 overruns:0 frame:0
          TX packets:119691 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:9903097 (9.4 MiB)  TX bytes:22465915 (21.4 MiB)

In this case the MAC Address is 40:A6:B7:DA:03:C1 the last 6 Digits is then DA03C1 This used to identify the PTP Delay Response

sudo tcpdump -i man11 -nn port 320  | grep "delay resp" | grep -i DA03C1 | head

Example output per below

fmadio@fmadio200v4-636:~$ sudo tcpdump -i man11 -nn port 320  | grep "delay resp" | grep -i DA03C1 | head
11:40:38.601755152 IP 192.168.2.5.320 > 224.0.1.129.320: PTPv2, v1 compat : no, msg type : delay resp msg, length : 54, domain : 4, reserved1 : 0, Flags [none], NS correction : 875, sub NS correction : 1, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 1, seq id : 44865, control : 3 (Delay_Resp), log message interval : 249, receiveTimeStamp : 1767590579 seconds, 412217267 nanoseconds, port identity : 0x40a6b7fffeda03c1, port id : 1
11:40:38.614403692 IP 192.168.2.5.320 > 224.0.1.129.320: PTPv2, v1 compat : no, msg type : delay resp msg, length : 54, domain : 4, reserved1 : 0, Flags [none], NS correction : 931, sub NS correction : 1, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 1, seq id : 44866, control : 3 (Delay_Resp), log message interval : 249, receiveTimeStamp : 1767590579 seconds, 424867467 nanoseconds, port identity : 0x40a6b7fffeda03c1, port id : 1
11:40:38.620255727 IP 192.168.2.5.320 > 224.0.1.129.320: PTPv2, v1 compat : no, msg type : delay resp msg, length : 54, domain : 4, reserved1 : 0, Flags [none], NS correction : 927, sub NS correction : 1, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 1, seq id : 44867, control : 3 (Delay_Resp), log message interval : 249, receiveTimeStamp : 1767590579 seconds, 430721046 nanoseconds, port identity : 0x40a6b7fffeda03c1, port id : 1
11:40:38.621544738 IP 192.168.2.5.320 > 224.0.1.129.320: PTPv2, v1 compat : no, msg type : delay resp msg, length : 54, domain : 4, reserved1 : 0, Flags [none], NS correction : 883, sub NS correction : 1, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 1, seq id : 44868, control : 3 (Delay_Resp), log message interval : 249, receiveTimeStamp : 1767590579 seconds, 432011224 nanoseconds, port identity : 0x40a6b7fffeda03c1, port id : 1
11:40:38.629227224 IP 192.168.2.5.320 > 224.0.1.129.320: PTPv2, v1 compat : no, msg type : delay resp msg, length : 54, domain : 4, reserved1 : 0, Flags [none], NS correction : 927, sub NS correction : 1, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 1, seq id : 44869, control : 3 (Delay_Resp), log message interval : 249, receiveTimeStamp : 1767590579 seconds, 439693285 nanoseconds, port identity : 0x40a6b7fffeda03c1, port id : 1
11:40:38.634837089 IP 192.168.2.5.320 > 224.0.1.129.320: PTPv2, v1 compat : no, msg type : delay resp msg, length : 54, domain : 4, reserved1 : 0, Flags [none], NS correction : 951, sub NS correction : 1, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 1, seq id : 44870, control : 3 (Delay_Resp), log message interval : 249, receiveTimeStamp : 1767590579 seconds, 445303920 nanoseconds, port identity : 0x40a6b7fffeda03c1, port id : 1
11:40:38.648480859 IP 192.168.2.5.320 > 224.0.1.129.320: PTPv2, v1 compat : no, msg type : delay resp msg, length : 54, domain : 4, reserved1 : 0, Flags [none], NS correction : 891, sub NS correction : 1, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 1, seq id : 44871, control : 3 (Delay_Resp), log message interval : 249, receiveTimeStamp : 1767590579 seconds, 458947593 nanoseconds, port identity : 0x40a6b7fffeda03c1, port id : 1
11:40:38.649711410 IP 192.168.2.5.320 > 224.0.1.129.320: PTPv2, v1 compat : no, msg type : delay resp msg, length : 54, domain : 4, reserved1 : 0, Flags [none], NS correction : 951, sub NS correction : 1, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 1, seq id : 44872, control : 3 (Delay_Resp), log message interval : 249, receiveTimeStamp : 1767590579 seconds, 460178635 nanoseconds, port identity : 0x40a6b7fffeda03c1, port id : 1
11:40:38.654342353 IP 192.168.2.5.320 > 224.0.1.129.320: PTPv2, v1 compat : no, msg type : delay resp msg, length : 54, domain : 4, reserved1 : 0, Flags [none], NS correction : 935, sub NS correction : 1, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 1, seq id : 44873, control : 3 (Delay_Resp), log message interval : 249, receiveTimeStamp : 1767590579 seconds, 464808596 nanoseconds, port identity : 0x40a6b7fffeda03c1, port id : 1
11:40:38.664690522 IP 192.168.2.5.320 > 224.0.1.129.320: PTPv2, v1 compat : no, msg type : delay resp msg, length : 54, domain : 4, reserved1 : 0, Flags [none], NS correction : 899, sub NS correction : 1, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 1, seq id : 44874, control : 3 (Delay_Resp), log message interval : 249, receiveTimeStamp : 1767590579 seconds, 475153445 nanoseconds, port identity : 0x40a6b7fffeda03c1, port id : 1

This confirms the PTP Master is responding to the peer(FMADIO) request

Confirm PTP4Linux is Synced

PTP should be synchronized, this is checked in the log file

/opt/fmadio/log/ptp_ptp4l.cur

Example output shown below

ptp4l[20260321_115502]: port 0: INITIALIZING to LISTENING on INIT_COMPLETE
ptp4l[20260321_115503]: port 1: new foreign master 84c807.fffe.2813c3-1
ptp4l[20260321_115505]: selected best master clock 84c807.fffe.2813c3
ptp4l[20260321_115505]: port 1: LISTENING to UNCALIBRATED on RS_SLAVE
ptp4l[20260321_115506]: port 1: minimum delay request interval 2^-7
ptp4l[20260321_115507]: master offset        -61 s0 freq   -3552 path delay      1768  grandmaster 84c807.fffe.2813c3
ptp4l[20260321_115508]: master offset        -93 s2 freq   -3584 path delay      1762  grandmaster 84c807.fffe.2813c3
ptp4l[20260321_115508]: port 1: UNCALIBRATED to SLAVE on MASTER_CLOCK_SELECTED
ptp4l[20260321_115509]: master offset        -13 s2 freq   -3597 path delay      1735  grandmaster 84c807.fffe.2813c3
ptp4l[20260321_115510]: master offset          3 s2 freq   -3585 path delay      1744  grandmaster 84c807.fffe.2813c3
ptp4l[20260321_115511]: master offset        -35 s2 freq   -3622 path delay      1750  grandmaster 84c807.fffe.2813c3
ptp4l[20260321_115512]: master offset         60 s2 freq   -3538 path delay      1699  grandmaster 84c807.fffe.2813c3
ptp4l[20260321_115513]: master offset         30 s2 freq   -3550 path delay      1734  grandmaster 84c807.fffe.2813c3
ptp4l[20260321_115514]: master offset         56 s2 freq   -3515 path delay      1743  grandmaster 84c807.fffe.2813c3
ptp4l[20260321_115515]: master offset        -49 s2 freq   -3603 path delay      1787  grandmaster 84c807.fffe.2813c3
ptp4l[20260321_115516]: master offset         24 s2 freq   -3544 path delay      1740  grandmaster 84c807.fffe.2813c3
ptp4l[20260321_115517]: master offset         19 s2 freq   -3542 path delay      1758  grandmaster 84c807.fffe.2813c3
ptp4l[20260321_115518]: master offset         -2 s2 freq   -3558 path delay      1773  grandmaster 84c807.fffe.2813c3
ptp4l[20260321_115519]: master offset        -22 s2 freq   -3578 path delay      1772  grandmaster 84c807.fffe.2813c3

Debug PTP Layer 2

PTP can run on Layer2 using 2 different modes, Peer-to-Peer or End-to-End, which mode can be determined by what MAC address is being used.

PTPv2 Transport Mode

Using tshark confirm the transport protocol PTP is running over layer2 without any IP or UDP encapsulation

sudo tshark -i phy11 -Y ptp -T fields  -e eth.dst -e frame.protocols

Example output shown below

fmadio@fmadio200v4-636:~$ sudo tshark -i phy11 -Y ptp -T fields  -e eth.dst -e frame.protocols
Capturing on 'phy11'
01:80:c2:00:00:0e       eth:ethertype:ethertype:ptp
01:80:c2:00:00:0e       eth:ethertype:ethertype:ptp
01:80:c2:00:00:0e       eth:ethertype:ethertype:ptp
01:80:c2:00:00:0e       eth:ethertype:ethertype:ptp

PTP is running L2 Peer-to-Peer Mode.

NOTE: the MAC Destination address is 01:80:c2:00:00:0e

The ptp4l.conf setting is

network_transport L2
delay_mechanism P2P

Example output

fmadio@fmadio200v4-636:~$ sudo tshark -i phy11 -Y ptp -T fields  -e eth.dst -e frame.protocols
Capturing on 'phy11'
01:80:c2:00:00:0e       eth:ethertype:ethertype:ptp
01:80:c2:00:00:0e       eth:ethertype:ethertype:ptp
01:80:c2:00:00:0e       eth:ethertype:ethertype:ptp
01:80:c2:00:00:0e       eth:ethertype:ethertype:ptp

Alternative using TCPDUMP

sudo tcpdump -i phy11 -nn -XX ether proto 0x88f7 and ether dst 01:80:c2:00:00:0e

Example output

fmadio@jump0:~$ sudo tcpdump -i qsfp0.port0 -nn -XX ether proto 0x88f7 and ether dst 01:80:c2:00:00:0e

18:58:19.267630 PTPv2, v1 compat : no, msg type : sync msg, length : 44, domain : 24, reserved1 : 0, Flags [none], NS correction : 0, sub NS correction : 104792065, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 2, seq id : 30946, control : 0 (sync msg), log message interval : 0, originTimeStamp : 1767588039 seconds, 228136429 nanoseconds
        0x0000:  0180 c200 000e 84c8 0728 13c3 88f7 0002  .........(......
        0x0010:  002c 1800 0000 0000 0000 063f 0001 0000  .,.........?....
        0x0020:  0000 84c8 07ff fe28 13c3 0002 78e2 0000  .......(....x...
        0x0030:  0000 695b 40c7 0d99 15ed 0000            ..i[@.......
18:58:19.267684 PTPv2, v1 compat : no, msg type : announce msg, length : 64, domain : 24, reserved1 : 0, Flags [none], NS correction : 0, sub NS correction : 0, reserved2 : 0, clock identity : 0x84c807fffe2813c3, port id : 2, seq id : 30946, control : 5 (Other), log message interval : 0, originTimeStamp : 1767588039 seconds 228136429 nanoseconds, origin cur utc :37, rsvd : 0, gm priority_1 : 128, gm clock class : 248, gm clock accuracy : 254, gm clock variance : 65535, gm priority_2 : 128, gm clock id : 0x84c807fffe2813c3, steps removed : 0, time source : 0x60
        0x0000:  0180 c200 000e 84c8 0728 13c3 88f7 0b02  .........(......
        0x0010:  0040 1800 0000 0000 0000 0000 0000 0000  .@..............
        0x0020:  0000 84c8 07ff fe28 13c3 0002 78e2 0500  .......(....x...
        0x0030:  0000 695b 40c7 0d99 15ed 0025 0080 f8fe  ..i[@......%....
        0x0040:  ffff 8084 c807 fffe 2813 c300 0060       ........(....`

PTP is running L2 End-to-End Mode

NOTE: the MAC Destination address is  01:1B:19:00:00:00

The ptp4l.conf setting is

network_transport L2
delay_mechanism E2E

TODO: Not verified

fmadio@fmadio200v4-636:~$ sudo tshark -i phy11 -Y ptp -T fields  -e eth.dst -e frame.protocols
Capturing on 'phy11'
.
todo

Alternative using TCPDUMP

sudo tcpdump -i phy11 -nn -XX ether proto 0x88f7 and ether dst 01:1b:19:00:00:00

Example output

todo

Confirm FMADIO Egressing

todo

Confirm  PTP Master Response

todo

Confirm PTP4Linux is Synced

todo