Packet capture applications such as
tcpdump can be useful to:
- Identify if any PTP messages are actually being received on the PTP interface.
- Identify if messages reported missing by
sfptpdare actually being received at the PTP interface.
- To inspect individual fields in PTP messages.
The following example shows how to use
tcpdump to capture only
# tcpdump -i <interface> dst port 319 or dst port 320 [-w <filename.pcap>]
<interface> is the network adapter interface being
Keep pcap files as small as possible, but large enough to capture an instance of the
sfptpd is experiencing.
tcpdumpcaptures packets sent/received on an interface, but these packets might be not be delivered to the
sfptpddaemon when they are prevented by other factors such as iptables rules, firewalls or reverse-path filters.