> 18.02.2022 00:51 Richard Cochran <richardcoch...@gmail.com> wrote: > On Thu, Feb 17, 2022 at 05:26:15PM +0100, Janusz Użycki wrote: > > > From our observations for IPv4 (L4) E2E it still applies to ptp4l. On Cisco > > and Netgear switches (even L3 set as L2 switch) IGMP snooping must be > > disabled for proper PTP multicast work. > > So their "IGMP snooping" feature is broken. Ask them to fix it.
I disagree. As far as I can tell, IGMP resending is done by kernel from version 4.9 upon notification. So basically, ptp4l will not work with any switch using IGMP in any way on older kernels. We probably should assume that devices with older kernel are all EOL but it is not uncommon for them to be still used. So maybe some annotation on what kernel version will ptp4l work or what are required kernel modules. > Cisco's PTP switch has issues. Have you looked at the residence > times? I don't feel like implementing workarounds for buggy >hardware. And is depending on kernel features for ptp4l to work properly a good way? I do not think it is hardware issue here, but rather dependence on kernel version and/or modules. Best regards Jakub _______________________________________________ Linuxptp-users mailing list Linuxptp-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-users
