Odd Connection Problems Since Unifi STP Blocked Port

bymatty · April 26, 2025, 3:02am

Hello There,

Last night, after watching a show on Infuse on my Apple 4K TV, the (internal) internet went down for a second, then came back up. Looking back at Infuse I noticed it lost connection to my TrueNAS mini and wouldn’t reconnect. When I went to my laptop, opened up my Brave browser, and went to login to my Unifi Network controller, it couldn’t locate the page. I go to login to my TrueNAS, but no, it can’t locate the page. Brave couldn’t locate the page for my QNAP either. However, I could login to the webpage for my Netgate 6100 router. Then, I remembered this happened before with Brave, though not my Apple TV. I opened Safari, and, wouldn’t you know it, I could mysteriously get to every page Brave couldn’t. Looking at Unifi’s network controller website on Safari, I saw there was an error message that it blocked port 4 due to my Apple TV causing a network loop, but it didn’t say how it was causing it. This setup has been working just fine for over a couple weeks, so I have no idea what to make of this.

The last time this happened, it wasn’t until I got a new laptop was I able to use Brave again to access the websites in question. But now, not only is Brave messing up, but Infuse on Apple TV as well and I’m just exhausted. I’ve rebooted everything, deleted my history in Brave, and rebooted my laptop. All this because Unifi thought my Apple TV was causing a network loop? How? And when everything went back to working, why did Infuse and Brave stay broken? Any ideas how to fix this? Or even how to troubleshoot this?

To further clarify, Infuse can still access my QNAP NAS, just not my TrueNAS Mini, despite trying re-enter my credentials. Oh, and another fun fact, while at work today, using Wireguard connected back home, using Brave I was able to access the websites in question. What the hell? Offsite I can access something I can’t access onsite? It’s supposed to be the other way around. So many variables, my head’s spinning.

My home network uses Netgate’s 6100 router connected to Unifi’s Aggregator using LACP & two SFP+ cables. I have another two SFP+ cables that go from the Aggregator to Unifi’s USW-Pro-24, also using LACP. STP Priority for the Aggregator is 0 and the STP priority for the USW-Pro-24 is 4096. Other than my NAS’ (a QNAP and a TrueNAS Mini), which are also connected to the Aggregator via SFP+ 10GB cables, all other wired connections use the 1 GB ports on the USW-Pro-24, including my two Unifi APs. Apple TV’s Wifi is disabled.

LTS_Tom · April 26, 2025, 9:58am

Are you on the latest 9.1 version? Is it the latest firmware? What else is in the UniFi logs?

bymatty · April 27, 2025, 2:07am

Hello @LTS_Tom. I was not on the latest 9.1 version, but I am now. I’m still unable to access my NAS’ or Unifi’s Network Controller websites via Brave or access my TrueNAS Mini via the Infuse app.

Below are the logs from Unifi (Critical logs and Client logs), followed by DHCP and DNS logs from PfSense running on my Netgate 6100. I included the DHCP logs due to repeated warnings and one Error (in Bold). I included the DNS logs only because I recall there being some joke about DNS “always” being the cause of networking problems. Please note I just pulled a small sample due to the massive amount of logs found.

Logs

Unifi:
Critical logs:

Multiple devices are using the same IP address: 192.168.80.67. Please check each device’s configuration to ensure none are communicating with a rogue DHCP server. Apr 24, 2025 at 21:43

USW Pro 24 PoE Port 4 was disabled by STP to prevent a network loop. It will be automatically re-enabled when the loop is no longer detected. Apr 24, 2025 at 02:13

Client logs:

MAC:address:1 disconnected from Journey on Aggregator Port 8. Time Connected: 4m 31s. Data Used: 0.00 B (up) / 0.00 B (down).|Apr 24, 2025 at 21:52|

QNAP_NAS disconnected from Journey on Aggregator Port 8. Time Connected: 7m 1s. Data Used: 0.00 B (up) / 0.00 B (down).|Apr 24, 2025 at 21:47|

Multiple devices are using the same IP address: 192.168.80.67. Please check each device’s configuration to ensure none are communicating with a rogue DHCP server.|Apr 24, 2025 at 21:43|

MAC:address:2 disconnected from Journey on Aggregator Port 8. Time Connected: 6m 2s. Data Used: 0.00 B (up) / 0.00 B (down).|Apr 24, 2025 at 20:29|

XMac-MBP connected to Journey on USW Pro 24 PoE Port 5. Connection Info: Link Speed GbE, 192.168.80.114.|Apr 24, 2025 at 19:34|

MAC:address:2 disconnected from Journey on Aggregator Port 8. Time Connected: 12m 27s. Data Used: 0.00 B (up) / 0.00 B (down).|Apr 24, 2025 at 19:31|

MAC:address:3 connected to Journey on USW Pro 24 PoE Port 3. Connection Info: Link Speed GbE, 192.168.80.12.|Apr 24, 2025 at 19:20|

MAC:address:2 disconnected from Journey on Aggregator Port 8. Time Connected: 6m 22s. Data Used: 0.00 B (up) / 0.00 B (down).|Apr 24, 2025 at 18:19|

MAC:address:2 disconnected from Journey on Aggregator Port 8. Time Connected: 6m 17s. Data Used: 0.00 B (up) / 0.00 B (down).|Apr 24, 2025 at 17:14|

PfSense:

DHCP Logs:
Apr 24 21:33:28 |kea-dhcp4|38758| WARN [kea-dhcp4.dhcp4.0x1586aaa12000] DHCP4_RESERVATIONS_LOOKUP_FIRST_ENABLED Multi-threading is enabled and host reservations lookup is always performed first.

Apr 24 21:33:28|kea-dhcp4|38758|WARN [kea-dhcp4.dhcpsrv.0x1586aaa12000] DHCPSRV_MT_DISABLED_QUEUE_CONTROL disabling dhcp queue control when multi-threading is enabled.

Apr 24 21:32:48|kea-dhcp4|62258|WARN [kea-dhcp4.dhcp4.0x360de1a12000] DHCP4_MULTI_THREADING_INFO enabled: yes, number of threads: 4, queue size: 64|

Apr 24 21:32:48|kea-dhcp4|62258|WARN [kea-dhcp4.dhcpsrv.0x360de1a12000] DHCPSRV_NO_SOCKETS_OPEN no interface configured to listen to DHCP traffic|

Apr 24 21:32:48|kea-dhcp4|62258|WARN [kea-dhcp4.dhcpsrv.0x360de1a12000] DHCPSRV_OPEN_SOCKET_FAIL failed to open socket: Failed to open socket on interface lagg0, reason: failed to bind fallback socket to address 192.168.80.1, port 67, reason: Address already in use - is another DHCP server running?

Apr 24 21:32:48|kea-dhcp4|62258|WARN [kea-dhcp4.dhcpsrv.0x360de1a12000] DHCPSRV_OPEN_SOCKET_FAIL failed to open socket: Failed to open socket on interface igc0, reason: failed to bind fallback socket to address 192.168.77.1, port 67, reason: Address already in use - is another DHCP server running?

Apr 24 21:32:48|kea-dhcp4|62258|WARN [kea-dhcp4.dhcp4.0x360de1a12000] DHCP4_RESERVATIONS_LOOKUP_FIRST_ENABLED Multi-threading is enabled and host reservations lookup is always performed first.

Apr 24 21:32:48|kea-dhcp4|62258|WARN [kea-dhcp4.dhcpsrv.0x360de1a12000] DHCPSRV_MT_DISABLED_QUEUE_CONTROL disabling dhcp queue control when multi-threading is enabled.

Apr 24 21:32:31|kea-dhcp4|80907|ERROR [kea-dhcp4.packets.0x10f4b9616d00] DHCP4_PACKET_SEND_FAIL [hwtype=1 d0:21:f9:da:da:24], cid=[no info], tid=0x34a39657: failed to send DHCPv4 packet: failed to send DHCPv4 packet: No buffer space available

Apr 24 21:29:51|kea-dhcp4|6925|WARN [kea-dhcp4.dhcp4.0x3eb641812000] DHCP4_MULTI_THREADING_INFO enabled: yes, number of threads: 4, queue size: 64|

Apr 24 21:29:51|kea-dhcp4|6925|WARN [kea-dhcp4.dhcpsrv.0x3eb641812000] DHCPSRV_NO_SOCKETS_OPEN no interface configured to listen to DHCP traffic|

Apr 24 21:29:51|kea-dhcp4|6925|WARN [kea-dhcp4.dhcpsrv.0x3eb641812000] DHCPSRV_OPEN_SOCKET_FAIL failed to open socket: Failed to open socket on interface lagg0, reason: failed to bind fallback socket to address 192.168.80.1, port 67, reason: Address already in use - is another DHCP server running?

Apr 24 21:29:51|kea-dhcp4|6925|WARN [kea-dhcp4.dhcpsrv.0x3eb641812000] DHCPSRV_OPEN_SOCKET_FAIL failed to open socket: Failed to open socket on interface igc0, reason: failed to bind fallback socket to address 192.168.77.1, port 67, reason: Address already in use - is another DHCP server running?

Apr 24 21:29:51|kea-dhcp4|6925|WARN [kea-dhcp4.dhcp4.0x3eb641812000] DHCP4_RESERVATIONS_LOOKUP_FIRST_ENABLED Multi-threading is enabled and host reservations lookup is always performed first.

DNS Logs:

Apr 24 21:32:24|unbound|62021|[62021:0] info: server stats for thread 0: 4 queries, 0 answers from cache, 4 recursions, 0 prefetch, 0 rejected by ip ratelimiting

LTS_Tom · April 27, 2025, 10:25am

Not sure why you are obscuring your internal IP addresses as it makes this harder to help you, but I do see a duplicate IP error which could be causing the issues.

bymatty · April 27, 2025, 6:21pm

Apologies for hiding the internal IP addresses @LTS_Tom, I’m still learning what’s safe to post and what’s not. I’ve put the internal IPs back into the logs I posted last night if you’re willing to take a 2nd look.

Regarding the duplicate IP error, are you referring to the one stating, “Multiple devices are using the same IP address: 192.168.80.67. Please check each device’s configuration to ensure none are communicating with a rogue DHCP server. Apr 24, 2025 at 21:43?” If so, I’ve been getting that error ever since I first installed the Unifi Pro-24 switch. When I first saw the error, I did multiple searches online and found several complaints about it, but no real fixes that I recall. The IP address belongs to my QNAP NAS, which has been the bane of my existence. I’m actually in the process of moving everything over to the TrueNAS mini.

If you think that is the underlying issue, I’ll do more research and see if I can track down how to fix it. Maybe it’s how I have the QNAP setup? If this issue could use a more in-depth look, I’ve been working with Eric (at CNWR) every 3-6 Months or so depending, and can schedule a time to go over it with him. Just let me know.

Thank you so much for your time!

Matt

LTS_Tom · April 28, 2025, 10:44am

A duplicate IP address will certainly stop you from access the device.