Plex disrupting DNS hourly for 2 minutes - weird

[sportmat_gmail.com]

Server Version#: Latest Stable Build - PMS Windows 10

Been using Plex since it came out and have been a lifelong user. Strangely, I’ve noticed that recurrently, Plex is causing a DNS outage for approx 2 minutes every hour. This looks like it’s when Plex does the Multicast sweep of the network.

To be clear - this does NOT affect any LAN connectivity to the PMS. It only hinders, for 2 minutes every hour, outbound internet connections from the PMS box.

It appears related to these folks issues as well.

r/PleX - Hourly DNS scan showing up in Pihole logs related to plex.direct

Here’s my data - I finally started ping tests looking for a pattern as to what was causing/when the issue was occurring. Then, by process of elimination, came to Plex.

After installing NetMon - the packet traffic during those 2 minutes are SSDP calls and Plex rolling through every IP on the 192.168.0.1/24 subnet. Once completed, DNS resumes. During this time, the network connection is never “interrupted”, but outbound internet connections from the PMS box are “connection refused”/cannot find the DNS obviously.

After disabling it at startup - the problem never occurred until the PMS was started again.

After starting it manually, the issue occurred precisely 1hr from the startup time and recurred every hour following. I’ve posted the ping logs below and truncated everything but the outage:

12/26/2022 6:52:35 PM - Reply from 1.1.1.1: bytes=32 time=14ms TTL=58
12/26/2022 6:52:36 PM - Reply from 1.1.1.1: bytes=32 time=14ms TTL=58
12/26/2022 6:52:40 PM - Request timed out.
12/26/2022 6:52:45 PM - Request timed out.
12/26/2022 6:52:50 PM - Request timed out.
12/26/2022 6:52:55 PM - Request timed out.
12/26/2022 6:53:00 PM - Request timed out.
12/26/2022 6:53:05 PM - Request timed out.
12/26/2022 6:53:10 PM - Request timed out.
12/26/2022 6:53:15 PM - Request timed out.
12/26/2022 6:53:20 PM - Request timed out.
12/26/2022 6:53:25 PM - Request timed out.
12/26/2022 6:53:30 PM - Request timed out.
12/26/2022 6:53:35 PM - Request timed out.
12/26/2022 6:53:40 PM - Request timed out.
12/26/2022 6:53:45 PM - Request timed out.
12/26/2022 6:53:50 PM - Request timed out.
12/26/2022 6:53:55 PM - Request timed out.
12/26/2022 6:54:00 PM - Request timed out.
12/26/2022 6:54:05 PM - Request timed out.
12/26/2022 7:52:34 PM - Reply from 1.1.1.1: bytes=32 time=14ms TTL=58
12/26/2022 7:52:35 PM - Reply from 1.1.1.1: bytes=32 time=14ms TTL=58
12/26/2022 7:52:36 PM - Reply from 1.1.1.1: bytes=32 time=15ms TTL=58
12/26/2022 7:52:41 PM - Request timed out.
12/26/2022 7:52:46 PM - Request timed out.
12/26/2022 7:52:51 PM - Request timed out.
12/26/2022 7:52:56 PM - Request timed out.
12/26/2022 7:53:01 PM - Request timed out.
12/26/2022 7:53:06 PM - Request timed out.
12/26/2022 7:53:11 PM - Request timed out.
12/26/2022 7:53:16 PM - Request timed out.
12/26/2022 7:53:21 PM - Request timed out.
12/26/2022 7:53:26 PM - Request timed out.
12/26/2022 7:53:31 PM - Request timed out.
12/26/2022 7:53:36 PM - Request timed out.
12/26/2022 7:53:41 PM - Request timed out.
12/26/2022 7:53:46 PM - Request timed out.
12/26/2022 7:53:51 PM - Request timed out.
12/26/2022 7:53:56 PM - Request timed out.
12/26/2022 7:54:01 PM - Request timed out.
12/26/2022 7:54:06 PM - Request timed out.
12/26/2022 7:54:11 PM - Request timed out.
12/26/2022 7:54:12 PM - Reply from 1.1.1.1: bytes=32 time=15ms TTL=58
12/26/2022 8:52:35 PM - Reply from 1.1.1.1: bytes=32 time=14ms TTL=58
12/26/2022 8:52:36 PM - Reply from 1.1.1.1: bytes=32 time=14ms TTL=58
12/26/2022 8:52:41 PM - Request timed out.
12/26/2022 8:52:46 PM - Request timed out.
12/26/2022 8:52:51 PM - Request timed out.
12/26/2022 8:52:56 PM - Request timed out.
12/26/2022 8:53:01 PM - Request timed out.
12/26/2022 8:53:06 PM - Request timed out.
12/26/2022 8:53:11 PM - Request timed out.
12/26/2022 8:53:16 PM - Request timed out.
12/26/2022 8:53:21 PM - Request timed out.
12/26/2022 8:53:26 PM - Request timed out.
12/26/2022 8:53:31 PM - Request timed out.
12/26/2022 8:53:36 PM - Request timed out.
12/26/2022 8:53:41 PM - Request timed out.
12/26/2022 8:53:46 PM - Request timed out.
12/26/2022 8:53:51 PM - Request timed out.
12/26/2022 8:53:56 PM - Request timed out.
12/26/2022 8:54:01 PM - Request timed out.
12/26/2022 8:54:06 PM - Request timed out.
12/26/2022 8:54:11 PM - Request timed out.
12/26/2022 8:54:12 PM - Reply from 1.1.1.1: bytes=32 time=15ms TTL=58
12/26/2022 8:54:13 PM - Reply from 1.1.1.1: bytes=32 time=15ms TTL=58

[FordGuy61]

Does your ISP have any built-in virus or security service?

See post below. It mentions interrupting all internet access when Plex is running, but might be similar to your issue.

User is on Century Link. Disabling their cyber security option resolved the problem. Comcast xfinity has a similar service.

Media Server Shutting Down Internet

Server Version#:1.29.2.6364 Whenever I download Plex Media Server it shuts down my internet on my machine. Not the whole network, just the machine I download it on. I’ve tried this with my desktop (Windows 11) and my laptop (Windows 10) and the same thing keeps happening. Once I uninstall the media server, my internet starts working again. Is there some kind of plex setting that can fix this? Is it maybe on my ISP’s end? A windows setting perhaps? Any help would be greatly appreciated. Thanks!