Symptom

N9K: Part of PTP follow_up messages fail and bad corrections are seen because PTP offset is over 1 micro-sec when 3 or more PTP slaves are connected to a PTP master device. `show system internal ptp bad-corrections` PTP past corrections ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Slave Port SUP Time Correction(ns) MeanPath Delay(ns) MasterTimestamp (sec, nsec) Slave Timestamp (sec, nsec) Sync-SeqID PTPLC ts_corr(ns) ---------- ------------------------------- ------------------ ------------------ ------------------ --------- ------------------ --------- ------- ------------------ Eth1/49 Tue Apr 3 09:38:22 2018 422975 7138266164 248 1522715946 559730127 1522715939 421464211 39061 602955251 Eth1/49 Tue Apr 3 09:38:51 2018 499826 -37000000042 251 1522715931 502625635 1522715968 502625928 38998 37602955224 Eth1/49 Tue Apr 3 09:34:54 2018 929722 18409 5827 1522715731 931223656 1522715731 931211074 37116 37602932418 Eth1/49 Tue Apr 3 09:34:54 2018 805486 -8654 245 1522715731 805751541 1522715731 805760440 37115 37602941072 Eth1/49 Mon Apr 2 19:52:25 2018 862332 29096 251 1522666382 864475231 1522666382 864446386 37729 37602580850 Eth1/49 Mon Apr 2 19:46:16 2018 141595 37000000560 248 1522666050 139709557 1522666013 139709245 35082 602576709 Eth1/49 Mon Apr 2 19:46:49 2018 370965 -36999999950 254 1522666009 370654580 1522666046 370654784 35052 37602576768 Eth1/49 Mon Apr 2 19:43:05 2018 288029 9817 286 1522665785 288418256 1522665785 288408725 32975 37602567725 ... FollowUp messages are less than Sync messages in the below log. It should be the same. 4KA_L015_MON_5sG14# show ptp counters all PTP Packet Counters of Interface Eth1/1: ---------------------------------------------------------------- Packet Type TX RX ---------------- -------------------- -------------------- Announce 87645 0 Sync 623996 0 <----- HERE!! FollowUp 448678 0 <----- HERE!! Delay Request 0 267793 Delay Response 267793 0 PDelay Request 0 0 PDelay Response 0 0 PDelay Followup 0 0 Management 85950 0

Conditions

Nexus 9000 using PTP. 3 or more PTP slaves are connected to a PTP master device. This issue does not occur when only 1 or 2 PTP slaves are connected or there is no PTP GM in the setup.

Workaround

Not available at this moment.

Further Problem Description