PTP Synchronization Doesn't Work When IGMP Snooping Is Enabled#
Basler GigE cameras send the PTP sync information to the multicast broadcast address 224.0.1.129.
This means that all multicast traffic will be flooded to all network ports, even if there is a "non camera" device connected. Many network switches supporting Layer-2 or Layer-3 offer the IGMP Snooping function to avoid such a multicast flooded traffic.
However, this requires the devices to send the IGMP query to enter a specific IGMP group.
As Basler GigE cameras do not enter any kind of IGMP group, IGMP snooping will block the PTP traffic of Basler GigE cameras.
The only way to prevent this issue is to disable IGMP snooping on the network switch.
Note: You may observe an issue when you enable the IGMP snooping and disable it. All cameras still take the PTP role as master and refuse to change the role to slave. Power cycling the cameras will solve this.