# Marantz SR5015 AVR – firmware bug causing excessive NTP polling (every 20 seconds) **URL:** \ **Category:** Uncategorized\ **Created:** [March 12, 2026, 5:59pm UTC](https://community.ntppool.org/t/marantz-sr5015-avr-firmware-bug-causing-excessive-ntp-polling-every-20-seconds/4283 "2026-03-12T17:59:33Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![torsten](https://avatars.discourse-cdn.com/v4/letter/t/8e8cbc/32.png) [@torsten](https://community.ntppool.org/u/torsten)\ **Post date:** [March 12, 2026, 5:59pm UTC](https://community.ntppool.org/t/marantz-sr5015-avr-firmware-bug-causing-excessive-ntp-polling-every-20-seconds/4283/1 "2026-03-12T17:59:33Z")
Hi all, I wanted to report a firmware bug in the Marantz SR5015 AV receiver that’s hammering NTP infrastructure. After a recent firmware update, the device sends NTP-related DNS queries every 20 seconds – 10 requests per cycle: - `time1.google.com` / `time2.google.com` / `time3.google.com` / `time4.google.com` (A + AAAA) - `0.linksys.pool.ntp.org` (A + AAAA) That’s approximately **4,300 DNS lookups per hour** or **43,000 per day** – per device. After each DNS resolution, it sends the actual NTP request. I have logs showing 65,000+ queries accumulated in roughly 36 hours. My network mitigates the impact: - AdGuard Home caches the DNS responses (response times ~0.1ms confirm cache hits) - dst-nat rules hijack all outbound NTP traffic to my local MikroTik Router So in my case, neither the pool nor Google’s NTP servers actually see the traffic. But I suspect the vast majority of SR5015 owners don’t have this setup – meaning this bug is likely generating millions of unnecessary requests against [pool.ntp.org](http://pool.ntp.org) and [time.google.com](http://time.google.com) globally. The device queries `0.linksys.pool.ntp.org` – that’s Linksys’ vendor zone, not Marantz’s. Suggests they’re using inherited code without a proper vendor zone. I’ve submitted a bug report with 1000 lines of DNS logs to Marantz DE support. No response yet. Wanted to give you a heads-up in case this is visible in pool traffic patterns or if there’s a way to escalate with vendors. Cheers ---
**Author:** ![mlichvar](https://avatars.discourse-cdn.com/v4/letter/m/e79b87/32.png) [@mlichvar](https://community.ntppool.org/u/mlichvar)\ **Post date:** [March 12, 2026, 6:19pm UTC](https://community.ntppool.org/t/marantz-sr5015-avr-firmware-bug-causing-excessive-ntp-polling-every-20-seconds/4283/2 "2026-03-12T18:19:27Z")
Can you please post `tcpdump -v` output (without IP addresses if you want to keep them private) showing some of the NTP requests? ---
**Author:** ![torsten](https://avatars.discourse-cdn.com/v4/letter/t/8e8cbc/32.png) [@torsten](https://community.ntppool.org/u/torsten)\ **Post date:** [March 12, 2026, 7:43pm UTC](https://community.ntppool.org/t/marantz-sr5015-avr-firmware-bug-causing-excessive-ntp-polling-every-20-seconds/4283/3 "2026-03-12T19:43:47Z")
Sure, here you go: sudo tcpdump -i eth0.30 -v -n port 123 and host 10.0.30.254 -c 30 tcpdump: listening on eth0.30, link-type EN10MB (Ethernet), snapshot length 262144 bytes 20:32:16.164103 IP (tos 0x48, ttl 63, id 17866, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.42525 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 563978829.226622598 (1917-11-15T12:47:09Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 563978829.226622598 (1917-11-15T12:47:09Z) 20:32:16.164174 IP (tos 0x48, ttl 63, id 21332, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.57812 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 493850233.576861346 (1915-08-26T20:37:13Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 493850233.576861346 (1915-08-26T20:37:13Z) 20:32:16.164222 IP (tos 0x48, ttl 63, id 55530, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.43218 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 3267198725.596538964 (2003-07-14T19:12:05Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 3267198725.596538964 (2003-07-14T19:12:05Z) 20:32:16.164265 IP (tos 0x48, ttl 63, id 22522, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.45629 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 2430285343.915923795 (1977-01-05T07:15:43Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 2430285343.915923795 (1977-01-05T07:15:43Z) 20:32:16.164381 IP (tos 0x48, ttl 63, id 55408, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.34224 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 815330357.519660853 (1925-11-02T16:39:17Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 815330357.519660853 (1925-11-02T16:39:17Z) 20:32:36.185634 IP (tos 0x48, ttl 63, id 19866, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.38556 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 4034398744.605182001 (2027-11-05T10:19:04Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 4034398744.605182001 (2027-11-05T10:19:04Z) 20:32:36.185704 IP (tos 0x48, ttl 63, id 23291, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.48777 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 2935196462.833741018 (1993-01-05T04:21:02Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 2935196462.833741018 (1993-01-05T04:21:02Z) 20:32:36.185751 IP (tos 0x48, ttl 63, id 55828, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.37040 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 3889099884.946815201 (2023-03-29T17:31:24Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 3889099884.946815201 (2023-03-29T17:31:24Z) 20:32:36.185863 IP (tos 0x48, ttl 63, id 23867, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.47649 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 3102538026.539462763 (1998-04-26T00:07:06Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 3102538026.539462763 (1998-04-26T00:07:06Z) 20:32:36.185980 IP (tos 0x48, ttl 63, id 56519, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.39742 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 1921798956.527349175 (1960-11-25T01:02:36Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 1921798956.527349175 (1960-11-25T01:02:36Z) 20:32:56.206162 IP (tos 0x48, ttl 63, id 21503, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.38364 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 496630368.599049167 (1915-09-28T00:52:48Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 496630368.599049167 (1915-09-28T00:52:48Z) 20:32:56.206215 IP (tos 0x48, ttl 63, id 24242, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.35129 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 1712793442.186327524 (1954-04-11T23:57:22Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 1712793442.186327524 (1954-04-11T23:57:22Z) 20:32:56.206325 IP (tos 0x48, ttl 63, id 56255, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.35438 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 454817106.682610539 (1914-06-01T02:05:06Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 454817106.682610539 (1914-06-01T02:05:06Z) 20:32:56.206326 IP (tos 0x48, ttl 63, id 24095, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.54097 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 3920274484.827418594 (2024-03-24T13:08:04Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 3920274484.827418594 (2024-03-24T13:08:04Z) 20:32:56.206371 IP (tos 0x48, ttl 63, id 57779, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.52239 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 2892811552.717540332 (1991-09-02T14:45:52Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 2892811552.717540332 (1991-09-02T14:45:52Z) 20:33:16.228834 IP (tos 0x48, ttl 63, id 22060, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.33181 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 2191987289.664144060 (1969-06-18T05:21:29Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 2191987289.664144060 (1969-06-18T05:21:29Z) 20:33:16.229311 IP (tos 0x48, ttl 63, id 25971, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.39218 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 2349432189.463985518 (1974-06-14T12:03:09Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 2349432189.463985518 (1974-06-14T12:03:09Z) 20:33:16.229856 IP (tos 0x48, ttl 63, id 57885, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.42238 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 2232868913.905411968 (1970-10-04T09:21:53Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 2232868913.905411968 (1970-10-04T09:21:53Z) 20:33:16.230479 IP (tos 0x48, ttl 63, id 24276, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.43769 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 734808686.219598611 (1923-04-15T17:31:26Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 734808686.219598611 (1923-04-15T17:31:26Z) 20:33:16.230967 IP (tos 0x48, ttl 63, id 57855, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.52509 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 3476407165.639297549 (2010-03-01T04:39:25Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 3476407165.639297549 (2010-03-01T04:39:25Z) 20:33:36.252859 IP (tos 0x48, ttl 63, id 23895, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.56704 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 2334423824.805036689 (1973-12-22T19:03:44Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 2334423824.805036689 (1973-12-22T19:03:44Z) 20:33:36.252924 IP (tos 0x48, ttl 63, id 26097, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.47066 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 280080920.840844357 (1908-11-16T16:15:20Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 280080920.840844357 (1908-11-16T16:15:20Z) 20:33:36.253052 IP (tos 0x48, ttl 63, id 58427, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.51535 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 3076136720.724097436 (1997-06-24T10:25:20Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 3076136720.724097436 (1997-06-24T10:25:20Z) 20:33:36.253054 IP (tos 0x48, ttl 63, id 25603, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.45724 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 203035239.183283398 (1906-06-08T22:40:39Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 203035239.183283398 (1906-06-08T22:40:39Z) 20:33:36.253109 IP (tos 0x48, ttl 63, id 59221, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.51893 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 1712032538.783680989 (1954-04-03T04:35:38Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 1712032538.783680989 (1954-04-03T04:35:38Z) 20:33:56.280829 IP (tos 0x48, ttl 63, id 25255, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.37316 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 4162381657.322145718 (2031-11-25T17:07:37Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 4162381657.322145718 (2031-11-25T17:07:37Z) 20:33:56.281275 IP (tos 0x48, ttl 63, id 26412, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.58140 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 3482150668.682849832 (2010-05-06T16:04:28Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 3482150668.682849832 (2010-05-06T16:04:28Z) 20:33:56.281777 IP (tos 0x48, ttl 63, id 58888, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.35674 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 1713922678.527505960 (1954-04-25T01:37:58Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 1713922678.527505960 (1954-04-25T01:37:58Z) 20:33:56.281978 IP (tos 0x48, ttl 63, id 27372, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.35656 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 1668834161.368705711 (1952-11-19T05:02:41Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 1668834161.368705711 (1952-11-19T05:02:41Z) 20:33:56.282194 IP (tos 0x48, ttl 63, id 60773, offset 0, flags [DF], proto UDP (17), length 76) 10.0.30.254.34743 \> 10.0.30.2.123: NTPv4, Client, length 48 Leap indicator: (0), Stratum 0 (unspecified), poll 0 (1s), precision 0 Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec) Reference Timestamp: 0.000000000 Originator Timestamp: 0.000000000 Receive Timestamp: 0.000000000 Transmit Timestamp: 1744706319.902365646 (1955-04-16T08:38:39Z) Originator - Receive Timestamp: 0.000000000 Originator - Transmit Timestamp: 1744706319.902365646 (1955-04-16T08:38:39Z) 30 packets captured 30 packets received by filter 0 packets dropped by kernel ---
**Author:** ![mlichvar](https://avatars.discourse-cdn.com/v4/letter/m/e79b87/32.png) [@mlichvar](https://community.ntppool.org/u/mlichvar)\ **Post date:** [March 13, 2026, 6:44am UTC](https://community.ntppool.org/t/marantz-sr5015-avr-firmware-bug-causing-excessive-ntp-polling-every-20-seconds/4283/4 "2026-03-13T06:44:04Z")
Ok, that doesn’t look like something that could be easily detected on a public server. ---
**Author:** ![torsten](https://avatars.discourse-cdn.com/v4/letter/t/8e8cbc/32.png) [@torsten](https://community.ntppool.org/u/torsten)\ **Post date:** [March 13, 2026, 7:26am UTC](https://community.ntppool.org/t/marantz-sr5015-avr-firmware-bug-causing-excessive-ntp-polling-every-20-seconds/4283/5 "2026-03-13T07:26:39Z")
**Update:** Turns out part of this was my own misconfiguration. My router was running as NTP server, but I forgot to open port 123 in the firewall. The device never got a response, so it kept retrying. After fixing that, the polling stopped immediately. However, the underlying behavior is still problematic: - poll 0 (1s) is way too aggressive for retries - No exponential backoff - Garbage timestamps in the requests - Using `0.linksys.pool.ntp.org` without a proper vendor zone So the firmware still has issues, but the constant polling was amplified by my setup. Apologies for the noise. ---
**Author:** ![davehart](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/davehart/32/1411_2.png) [@davehart](https://community.ntppool.org/u/davehart)\ **Post date:** [March 13, 2026, 7:44pm UTC](https://community.ntppool.org/t/marantz-sr5015-avr-firmware-bug-causing-excessive-ntp-polling-every-20-seconds/4283/6 "2026-03-13T19:44:56Z")
> [@torsten](#): > > Apologies for the noise. No apology necessary. The rapid-fire retries are abusive. Is this a regression with the latest version of their firmware? Regardless, which version did you see this with? Thanks for sharing your findings. Please keep us posted on the vendor response. ---
**Author:** ![torsten](https://avatars.discourse-cdn.com/v4/letter/t/8e8cbc/32.png) [@torsten](https://community.ntppool.org/u/torsten)\ **Post date:** [March 14, 2026, 10:23am UTC](https://community.ntppool.org/t/marantz-sr5015-avr-firmware-bug-causing-excessive-ntp-polling-every-20-seconds/4283/7 "2026-03-14T10:23:14Z")
Firmware version: 4400-2103-8116-8080 Can’t confirm if it’s a regression – I only started monitoring network traffic recently. The device has been running for years, so I wouldn’t have noticed before. Marantz support responded asking for HEOS app diagnostics, which completely misses the point. I’ve clarified that this is a firmware-level NTP issue, not an app problem. Will keep you posted. ---
**Author:** ![Bas](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/bas/32/465_2.png) [@Bas](https://community.ntppool.org/u/Bas)\ **Post date:** [March 18, 2026, 3:56pm UTC](https://community.ntppool.org/t/marantz-sr5015-avr-firmware-bug-causing-excessive-ntp-polling-every-20-seconds/4283/8 "2026-03-18T15:56:15Z")
They won’t reply to you any more, as they have no clue what the issue is. I tried with several ‘service-desks’ they typical say it’s noted and most people have no issues and bury it deep into the lowest drawer they have. Don’t expect much. Hardware makers are typical dumb and don’t like to deal with these issues, so they tend to ignore it. ---
**Author:** ![nobrowser](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/nobrowser/32/568_2.png) [@nobrowser](https://community.ntppool.org/u/nobrowser)\ **Post date:** [March 22, 2026, 2:41am UTC](https://community.ntppool.org/t/marantz-sr5015-avr-firmware-bug-causing-excessive-ntp-polling-every-20-seconds/4283/9 "2026-03-22T02:41:04Z")
I can’t resist posting an off-topic example of this pattern: > **[New M3000 Pro 5G keeps shutting down](https://www.reddit.com/r/Calyx/comments/12b48ta/new_m3000_pro_5g_keeps_shutting_down/)** > > This thing is driving me crazy. It keeps turning itself off. It's plugged into constant power. Sleep mode and auto shutdown are both set to "never". It's in a cool place. > > Usually it takes hours to turn off but just now while typing this post it did... GRRRRRRRRRR