# Web browsing / DNS stalls completely during active TCP LAN sync (Debian & Pixel 8)
**URL:** https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979
**Category:** Support
**Created:** [August 4, 2026, 3:09pm UTC](https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979 "2026-08-04T15:09:04Z")
**Posts on this page:** 18
**Page:** 1
### Author:  [@Cheer1](https://forum.syncthing.net/u/Cheer1)
#### Post date: [August 4, 2026, 3:09pm UTC](https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979/1 "2026-08-04T15:09:04Z")
### Issue
Whenever Syncthing is actively transferring files (such as an Obsidian vault or media/backup folders), web browsing completely stalls across the device/network. Web pages fail to resolve or time out.
The moment I pause the peers on either device, web browsing immediately returns to normal.
### Environment
- **Device A (Host):** Debian GNU/Linux 13 (trixie) x86\_64, Syncthing v2.1.2
- **Device B (Client):** Google Pixel 8, Syncthing Android App
- **Network:** Local Wi-Fi (Router at `192.168.0.1`), both devices assigned static local IPs
- **Connection Type:** Direct TCP LAN (`tcp4://192.168.0.229:22000`, `connection.lan = true`)
### Steps I have taken
1. **Forced Direct TCP LAN:** Confirmed that connection is purely direct local TCP (`tcp4://192.168.0.229:22000`) with relays disabled, ruling out WAN relay latency.
2. **Ping & Connectivity:** Running a `ping` between the Debian host and Pixel 8 during the stall shows stable ICMP replies (~10–70 ms) with 0% packet loss, so basic LAN routing remains active. Firewall (UFW) on the Debian host is disabled.
3. **Internal Rate Limiting:** I tried setting incoming and outgoing speed limits within Syncthing’s settings. While this successfully reduced bandwidth consumption and slowed the sync to a crawl, **the web loading failure persisted unchanged**.
4. **Environment Check:** No VPNs, local ad-blocking proxies, or custom DNS wrappers are active on the Pixel 8.
This is not the comprehensive list of things I have tried. I really spent hours hacking and trying things out.
### Please help
Any suggestions or diagnostic steps would be greatly appreciated!
---
### Author:  [@tomasz86](https://forum.syncthing.net/u/tomasz86)
#### Post date: [August 4, 2026, 3:48pm UTC](https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979/2 "2026-08-04T15:48:08Z")
What router are you using specifically? Is it something decent?
---
### Author:  [@Cheer1](https://forum.syncthing.net/u/Cheer1)
#### Post date: [August 4, 2026, 3:55pm UTC](https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979/3 "2026-08-04T15:55:00Z")
I use this router: [Play BOX NET router HFC | Play](https://www.play.pl/pomoc/wsparcie-techniczne/routery-i-modemy/play-box-net-router-hfc).
Before switching to BasicSync and Pixel 8 from Pixel 5 and the deprecated syncthing android fork at version 1.2 everything worked on this network.
---
### Author:  [@Cheer1](https://forum.syncthing.net/u/Cheer1)
#### Post date: [August 4, 2026, 4:55pm UTC](https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979/4 "2026-08-04T16:55:28Z")
This is insane! I can’t even send 6 kB of logs to my phone. I have to pause on _both peers_ not just _one peer_ for my network to work again.
Important note: the WiFi on my phone works fine, it’s just my laptop that completely halts.
Here are some logs (from the Debian laptop):
```plaintext
2026-08-04 18:41:32 WRN Service failed (error="listen udp 0.0.0.0:22000: bind: address already in use" supervisor=listenerSupervisor@quic://0.0.0.0:22000 service=quic://0.0.0.0:22000 log.pkg=connections)
2026-08-04 18:41:32 WRN Failed to listen (QUIC) (error="listen udp 0.0.0.0:22000: bind: address already in use" log.pkg=connections)
2026-08-04 18:41:32 WRN Service failed (error="listen udp 0.0.0.0:22000: bind: address already in use" supervisor=listenerSupervisor@quic://0.0.0.0:22000 service=quic://0.0.0.0:22000 log.pkg=connections)
2026-08-04 18:42:37 WRN Failed to listen (QUIC) (error="listen udp 0.0.0.0:22000: bind: address already in use" log.pkg=connections)
2026-08-04 18:42:37 WRN Service failed (error="listen udp 0.0.0.0:22000: bind: address already in use" supervisor=listenerSupervisor@quic://0.0.0.0:22000 service=quic://0.0.0.0:22000 log.pkg=connections)
2026-08-04 18:42:37 WRN Failed to listen (QUIC) (error="listen udp 0.0.0.0:22000: bind: address already in use" log.pkg=connections)
2026-08-04 18:42:37 WRN Service failed (error="listen udp 0.0.0.0:22000: bind: address already in use" supervisor=listenerSupervisor@quic://0.0.0.0:22000 service=quic://0.0.0.0:22000 log.pkg=connections)
2026-08-04 18:42:37 WRN Failed to listen (QUIC) (error="listen udp 0.0.0.0:22000: bind: address already in use" log.pkg=connections)
2026-08-04 18:42:37 WRN Service failed (error="listen udp 0.0.0.0:22000: bind: address already in use" supervisor=listenerSupervisor@quic://0.0.0.0:22000 service=quic://0.0.0.0:22000 log.pkg=connections)
2026-08-04 18:43:41 INF Resuming device (device=ULG3HXW log.pkg=model)
2026-08-04 18:43:41 INF Resuming device (device=4YVXX6E log.pkg=model)
2026-08-04 18:43:41 WRN Failed to exchange Hello messages (device=4YVXX6E address=192.168.0.150:22000 error=EOF log.pkg=connections)
2026-08-04 18:43:43 WRN Failed to listen (QUIC) (error="listen udp 0.0.0.0:22000: bind: address already in use" log.pkg=connections)
2026-08-04 18:43:43 WRN Service failed (error="listen udp 0.0.0.0:22000: bind: address already in use" supervisor=listenerSupervisor@quic://0.0.0.0:22000 service=quic://0.0.0.0:22000 log.pkg=connections)
2026-08-04 18:43:43 WRN Failed to listen (QUIC) (error="listen udp 0.0.0.0:22000: bind: address already in use" log.pkg=connections)
2026-08-04 18:43:43 WRN Service failed (error="listen udp 0.0.0.0:22000: bind: address already in use" supervisor=listenerSupervisor@quic://0.0.0.0:22000 service=quic://0.0.0.0:22000 log.pkg=connections)
2026-08-04 18:43:43 WRN Failed to listen (QUIC) (error="listen udp 0.0.0.0:22000: bind: address already in use" log.pkg=connections)
2026-08-04 18:43:43 WRN Service failed (error="listen udp 0.0.0.0:22000: bind: address already in use" supervisor=listenerSupervisor@quic://0.0.0.0:22000 service=quic://0.0.0.0:22000 log.pkg=connections)
2026-08-04 18:43:54 INF Established secure connection (device=4YVXX6E connection.local=192.168.0.229:22000 connection.remote=192.168.0.150:44780 connection.type=tcp-server connection.lan=true connection.crypto=TLS1.3-TLS_CHACHA20_POLY1305_SHA256 connection.prio=10 connection.id=668KVG6EBC1V24H3DGFF1F0HVK log.pkg=connections)
2026-08-04 18:43:54 INF New device connection (device=4YVXX6E address=192.168.0.150:44780 remote.name=pixel-8 remote.client=syncthing remote.version=v2.1.2-basicsync.0 log.pkg=model)
2026-08-04 18:43:56 INF Updated file metadata (folder.label=Vaults folder.id=m9sza-x6cmo folder.type=sendreceive file.name=main/.obsidian-mobile/app.json file.modified="2026-08-04 17:13:14.256417387 +0200 CEST" file.permissions=0660 file.size=1363 file.blocksize=131072 log.pkg=model)
2026-08-04 18:43:56 INF Updated file metadata (folder.label=Vaults folder.id=m9sza-x6cmo folder.type=sendreceive file.name=main/.obsidian-mobile/community-plugins.json file.modified="2026-08-04 17:13:16.804417388 +0200 CEST" file.permissions=0660 file.size=326 file.blocksize=131072 log.pkg=model)
2026-08-04 18:43:56 INF Updated file metadata (folder.label=Vaults folder.id=m9sza-x6cmo folder.type=sendreceive file.name=main/.obsidian-mobile/core-plugins.json file.modified="2026-08-04 17:13:13.852417387 +0200 CEST" file.permissions=0660 file.size=699 file.blocksize=131072 log.pkg=model)
2026-08-04 18:43:56 INF Updated file metadata (folder.label=Vaults folder.id=m9sza-x6cmo folder.type=sendreceive file.name=main/.obsidian-mobile/plugins/obsidian-minimal-settings/data.json file.modified="2026-08-04 17:13:14.782 +0200 CEST" file.permissions=0660 file.size=1086 file.blocksize=131072 log.pkg=model)
2026-08-04 18:43:56 INF Updated file metadata (folder.label=Vaults folder.id=m9sza-x6cmo folder.type=sendreceive file.name=main/.obsidian-mobile/appearance.json file.modified="2026-08-04 17:13:14.260417387 +0200 CEST" file.permissions=0660 file.size=478 file.blocksize=131072 log.pkg=model)
2026-08-04 18:43:56 INF Synced file (folder.label=Vaults folder.id=m9sza-x6cmo folder.type=sendreceive file.name=main/.obsidian-mobile/workspace-mobile.json file.modified="2026-08-04 17:19:25.861799563 +0200 CEST" file.permissions=0660 file.size=11101 file.blocksize=131072 blocks.local=0 blocks.download=1 log.pkg=model)
2026-08-04 18:43:56 INF Synced file (folder.label=Pictures folder.id=ixk2m-eqxgh folder.type=sendreceive file.name=Screenshots/Screenshot_20260804-170248_BasicSync.png file.modified="2026-08-04 17:02:48.704417082 +0200 CEST" file.permissions=0770 file.size=218875 file.blocksize=131072 blocks.local=0 blocks.download=2 log.pkg=model)
2026-08-04 18:43:56 INF Synced file (folder.label=Pictures folder.id=ixk2m-eqxgh folder.type=sendreceive file.name=Screenshots/Screenshot_20260804-164150_BasicSync.png file.modified="2026-08-04 16:41:51.104416467 +0200 CEST" file.permissions=0770 file.size=227568 file.blocksize=131072 blocks.local=0 blocks.download=2 log.pkg=model)
2026-08-04 18:43:57 INF Ready to synchronize (folder.label=SwiftBackup folder.id=swift-backup folder.type=receiveonly log.pkg=model)
2026-08-04 18:43:57 INF Unpaused folder (folder.label=SwiftBackup folder.id=swift-backup folder.type=receiveonly log.pkg=model)
2026-08-04 18:43:57 INF Completed initial scan (folder.label=SwiftBackup folder.id=swift-backup folder.type=receiveonly log.pkg=model)
2026-08-04 18:44:10 INF Established secure connection (device=4YVXX6E connection.local=192.168.0.229:56646 connection.remote=192.168.0.150:22000 connection.type=tcp-client connection.lan=true connection.crypto=TLS1.3-TLS_CHACHA20_POLY1305_SHA256 connection.prio=10 connection.id=668KVI2K5L7VOCQREES1GS0CKE log.pkg=connections)
2026-08-04 18:44:10 INF Additional device connection (device=4YVXX6E address=192.168.0.150:22000 count=1 log.pkg=model)
2026-08-04 18:44:14 INF Established secure connection (device=4YVXX6E connection.local=192.168.0.229:22000 connection.remote=192.168.0.150:44294 connection.type=tcp-server connection.lan=true connection.crypto=TLS1.3-TLS_CHACHA20_POLY1305_SHA256 connection.prio=10 connection.id=668KVIIUICO9COL0G39L6C90O6 log.pkg=connections)
2026-08-04 18:44:14 INF Additional device connection (device=4YVXX6E address=192.168.0.150:44294 count=2 log.pkg=model)
```
---
### Author:  [@tomasz86](https://forum.syncthing.net/u/tomasz86)
#### Post date: [August 4, 2026, 5:03pm UTC](https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979/5 "2026-08-04T17:03:28Z")
Can you show screenshots of the Syncthing web GUI from both sides? On Android, you can access the web GUI from the left slide-out menu. Before taking the screenshots, olease unfold the information under the relevant remote device.
---
### Author:  [@Cheer1](https://forum.syncthing.net/u/Cheer1)
#### Post date: [August 4, 2026, 5:24pm UTC](https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979/6 "2026-08-04T17:24:10Z")
 
---
### Author:  [@bt90](https://forum.syncthing.net/u/bt90)
#### Post date: [August 4, 2026, 8:58pm UTC](https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979/7 "2026-08-04T20:58:16Z")
Could you hook your laptop to your router using ethernet? We need to rule a few things out to get a better picture.
---
### Author:  [@Cheer1](https://forum.syncthing.net/u/Cheer1)
#### Post date: [August 5, 2026, 12:43pm UTC](https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979/8 "2026-08-05T12:43:32Z")
Hello again after the experiment.
When connected via Ethernet cable, I could load a YouTube video and sync a few GBs within a minute. When I disconnected it, the YouTube video could not refresh until some files stopped syncing. When both devices are connected but there is nothing syncing, I can use the internet just fine.
P.S Unfortunately, I cannot use an Ethernet cable permanently because it’s far from my computer and I don’t have a routing for it.
Here’s a log from the affected debian machine.
```plaintext
2026-08-05 14:34:07 INF Resuming device (device=ULG3HXW log.pkg=model)
2026-08-05 14:34:07 INF Resuming device (device=4YVXX6E log.pkg=model)
2026-08-05 14:34:08 WRN Failed to exchange Hello messages (device=4YVXX6E address=192.168.0.150:22000 error=EOF log.pkg=connections)
2026-08-05 14:34:29 WRN Failed to exchange Hello messages (device=4YVXX6E address=192.168.0.150:22000 error=EOF log.pkg=connections)
2026-08-05 14:34:49 WRN Failed to exchange Hello messages (device=4YVXX6E address=192.168.0.150:22000 error=EOF log.pkg=connections)
2026-08-05 14:34:54 INF Established secure connection (device=4YVXX6E connection.local=192.168.0.229:22000 connection.remote=192.168.0.150:59312 connection.type=tcp-server connection.lan=true connection.crypto=TLS1.3-TLS_CHACHA20_POLY1305_SHA256 connection.prio=10 connection.id=668T3FCFMUJ7ILU6P09OGUQTVM log.pkg=connections)
2026-08-05 14:34:54 INF New device connection (device=4YVXX6E address=192.168.0.150:59312 remote.name=pixel-8 remote.client=syncthing remote.version=v2.1.2-basicsync.0 log.pkg=model)
2026-08-05 14:34:56 INF Updated file metadata (folder.label=Vaults folder.id=m9sza-x6cmo folder.type=sendreceive file.name=main/.obsidian-mobile/appearance.json file.modified="2026-08-05 13:10:52.422786837 +0200 CEST" file.permissions=0660 file.size=478 file.blocksize=131072 log.pkg=model)
2026-08-05 14:34:56 INF Updated file metadata (folder.label=Vaults folder.id=m9sza-x6cmo folder.type=sendreceive file.name=main/.obsidian-mobile/plugins/obsidian-minimal-settings/data.json file.modified="2026-08-05 13:10:52.871 +0200 CEST" file.permissions=0660 file.size=1086 file.blocksize=131072 log.pkg=model)
2026-08-05 14:34:56 INF Updated file metadata (folder.label=Vaults folder.id=m9sza-x6cmo folder.type=sendreceive file.name=main/.obsidian-mobile/graph.json file.modified="2026-08-05 10:04:27.019 +0200 CEST" file.permissions=0660 file.size=512 file.blocksize=131072 log.pkg=model)
2026-08-05 14:34:56 INF Updated file metadata (folder.label=Vaults folder.id=m9sza-x6cmo folder.type=sendreceive file.name=main/.obsidian-mobile/app.json file.modified="2026-08-05 13:10:52.414786837 +0200 CEST" file.permissions=0660 file.size=1363 file.blocksize=131072 log.pkg=model)
2026-08-05 14:34:56 INF Updated file metadata (folder.label=Vaults folder.id=m9sza-x6cmo folder.type=sendreceive file.name=main/.obsidian-mobile/core-plugins.json file.modified="2026-08-05 13:10:52.014786836 +0200 CEST" file.permissions=0660 file.size=699 file.blocksize=131072 log.pkg=model)
2026-08-05 14:34:56 INF Updated file metadata (folder.label=Vaults folder.id=m9sza-x6cmo folder.type=sendreceive file.name=main/.obsidian-mobile/community-plugins.json file.modified="2026-08-05 13:10:54.694786838 +0200 CEST" file.permissions=0660 file.size=326 file.blocksize=131072 log.pkg=model)
2026-08-05 14:34:57 INF Synced file (folder.label=DCIM folder.id=3doyj-3yj2o folder.type=sendreceive file.name=2026-08-05-12-37-35-183.jpg file.modified="2026-08-05 12:37:35.754785862 +0200 CEST" file.permissions=0770 file.size=1901726 file.blocksize=131072 blocks.local=14 blocks.download=1 log.pkg=model)
2026-08-05 14:34:57 INF Synced file (folder.label=DCIM folder.id=3doyj-3yj2o folder.type=sendreceive file.name=2026-08-05-11-37-35-672.jpg file.modified="2026-08-05 11:37:36.226784104 +0200 CEST" file.permissions=0770 file.size=1449743 file.blocksize=131072 blocks.local=11 blocks.download=1 log.pkg=model)
2026-08-05 14:34:57 INF Synced file (folder.label=DCIM folder.id=3doyj-3yj2o folder.type=sendreceive file.name=2026-08-05-11-55-51-472.jpg file.modified="2026-08-05 11:55:51.982784639 +0200 CEST" file.permissions=0770 file.size=1693822 file.blocksize=131072 blocks.local=12 blocks.download=1 log.pkg=model)
2026-08-05 14:34:57 INF Synced file (folder.label=DCIM folder.id=3doyj-3yj2o folder.type=sendreceive file.name=2026-08-05-09-11-07-645.jpg file.modified="2026-08-05 09:11:08.146969947 +0200 CEST" file.permissions=0770 file.size=1977963 file.blocksize=131072 blocks.local=15 blocks.download=1 log.pkg=model)
2026-08-05 14:34:57 INF Synced file (folder.label=DCIM folder.id=3doyj-3yj2o folder.type=sendreceive file.name=2026-08-05-08-35-23-152.jpg file.modified="2026-08-05 08:35:23.629157561 +0200 CEST" file.permissions=0770 file.size=1562987 file.blocksize=131072 blocks.local=11 blocks.download=1 log.pkg=model)
2026-08-05 14:34:57 INF Synced file (folder.label=DCIM folder.id=3doyj-3yj2o folder.type=sendreceive file.name=2026-08-05-09-55-05-712.jpg file.modified="2026-08-05 09:55:06.24369328 +0200 CEST" file.permissions=0770 file.size=2060284 file.blocksize=131072 blocks.local=15 blocks.download=1 log.pkg=model)
2026-08-05 14:34:57 INF Synced file (folder.label=DCIM folder.id=3doyj-3yj2o folder.type=sendreceive file.name=2026-08-05-11-55-54-251.jpg file.modified="2026-08-05 11:55:54.766784641 +0200 CEST" file.permissions=0770 file.size=2021432 file.blocksize=131072 blocks.local=15 blocks.download=1 log.pkg=model)
2026-08-05 14:34:57 INF Synced file (folder.label=DCIM folder.id=3doyj-3yj2o folder.type=sendreceive file.name=2026-08-05-12-57-00-596.jpg file.modified="2026-08-05 12:57:01.066786431 +0200 CEST" file.permissions=0770 file.size=2055477 file.blocksize=131072 blocks.local=15 blocks.download=1 log.pkg=model)
2026-08-05 14:34:57 INF Synced file (folder.label=DCIM folder.id=3doyj-3yj2o folder.type=sendreceive file.name=2026-08-05-11-58-24-580.jpg file.modified="2026-08-05 11:58:25.094784714 +0200 CEST" file.permissions=0770 file.size=1502262 file.blocksize=131072 blocks.local=11 blocks.download=1 log.pkg=model)
2026-08-05 14:34:57 INF Synced file (folder.label=DCIM folder.id=3doyj-3yj2o folder.type=sendreceive file.name=2026-08-05-12-37-38-711.jpg file.modified="2026-08-05 12:37:39.238785863 +0200 CEST" file.permissions=0770 file.size=2106419 file.blocksize=131072 blocks.local=16 blocks.download=1 log.pkg=model)
2026-08-05 14:34:57 INF Synced file (folder.label=DCIM folder.id=3doyj-3yj2o folder.type=sendreceive file.name=2026-08-05-09-33-06-115.jpg file.modified="2026-08-05 09:33:06.647701826 +0200 CEST" file.permissions=0770 file.size=2078924 file.blocksize=131072 blocks.local=15 blocks.download=1 log.pkg=model)
2026-08-05 14:34:57 INF Synced file (folder.label=DCIM folder.id=3doyj-3yj2o folder.type=sendreceive file.name=2026-08-05-08-50-15-729.jpg file.modified="2026-08-05 08:50:16.210969335 +0200 CEST" file.permissions=0770 file.size=2045770 file.blocksize=131072 blocks.local=15 blocks.download=1 log.pkg=model)
2026-08-05 14:34:57 INF Synced file (folder.label=Vaults folder.id=m9sza-x6cmo folder.type=sendreceive file.name=main/.obsidian-mobile/workspace-mobile.json file.modified="2026-08-05 13:10:59.79878684 +0200 CEST" file.permissions=0660 file.size=9079 file.blocksize=131072 blocks.local=0 blocks.download=1 log.pkg=model)
2026-08-05 14:34:57 INF Synced file (folder.label=Vaults folder.id=m9sza-x6cmo folder.type=sendreceive file.name=main/.obsidian-mobile/workspaces.json file.modified="2026-08-05 10:01:51.93 +0200 CEST" file.permissions=0660 file.size=13982 file.blocksize=131072 blocks.local=0 blocks.download=1 log.pkg=model)
2026-08-05 14:34:57 INF Synced file (folder.label=Vaults folder.id=m9sza-x6cmo folder.type=sendreceive file.name="main/110-119 journals/111 daily/05-08-2026.md" file.modified="2026-08-05 10:02:31.166900727 +0200 CEST" file.permissions=0660 file.size=669 file.blocksize=131072 blocks.local=0 blocks.download=1 log.pkg=model)
2026-08-05 14:35:09 INF Established secure connection (device=4YVXX6E connection.local=192.168.0.211:22000 connection.remote=192.168.0.150:22000 connection.type=tcp-client connection.lan=true connection.crypto=TLS1.3-TLS_CHACHA20_POLY1305_SHA256 connection.prio=10 connection.id=668T3H2BKOAQ6R767BGEK27AFM log.pkg=connections)
2026-08-05 14:35:09 INF Additional device connection (device=4YVXX6E address=192.168.0.150:22000 count=1 log.pkg=model)
2026-08-05 14:35:14 INF Established secure connection (device=4YVXX6E connection.local=192.168.0.229:22000 connection.remote=192.168.0.150:45416 connection.type=tcp-server connection.lan=true connection.crypto=TLS1.3-TLS_CHACHA20_POLY1305_SHA256 connection.prio=10 connection.id=668T3HN6EL3I4TPQT76NVMP09U log.pkg=connections)
2026-08-05 14:35:14 INF Additional device connection (device=4YVXX6E address=192.168.0.150:45416 count=2 log.pkg=model)
2026-08-05 14:36:06 INF Synced file (folder.label=DCIM folder.id=3doyj-3yj2o folder.type=sendreceive file.name=2026-08-05-14-35-23-777.mp4 file.modified="2026-08-05 14:35:51.480237864 +0200 CEST" file.permissions=0770 file.size=54151205 file.blocksize=131072 blocks.local=2 blocks.download=412 log.pkg=model)
2026-08-05 14:38:07 INF Created or updated directory (folder.label=Downloads folder.id=qsc6h-egxsh folder.type=sendreceive dir.name=Fizjoterapia dir.permissions=0770 log.pkg=model)
2026-08-05 14:38:08 INF Synced file (folder.label=Downloads folder.id=qsc6h-egxsh folder.type=sendreceive file.name=Fizjoterapia/lezenie-diamencikiem.mp4 file.modified="2025-08-27 11:08:03 +0200 CEST" file.permissions=0660 file.size=140757209 file.blocksize=131072 blocks.local=1074 blocks.download=0 log.pkg=model)
2026-08-05 14:38:09 INF Synced file (folder.label=Downloads folder.id=qsc6h-egxsh folder.type=sendreceive file.name=Fizjoterapia/oddychanie-side-plank.mov file.modified="2025-08-06 11:09:48 +0200 CEST" file.permissions=0660 file.size=140040941 file.blocksize=131072 blocks.local=1069 blocks.download=0 log.pkg=model)
2026-08-05 14:38:09 INF Synced file (folder.label=Downloads folder.id=qsc6h-egxsh folder.type=sendreceive file.name=Fizjoterapia/oddech-w-diamencik.mp4 file.modified="2025-09-17 11:20:59 +0200 CEST" file.permissions=0660 file.size=127746110 file.blocksize=131072 blocks.local=975 blocks.download=0 log.pkg=model)
2026-08-05 14:38:10 INF Synced file (folder.label=Downloads folder.id=qsc6h-egxsh folder.type=sendreceive file.name=Fizjoterapia/fetal-twist.mp4 file.modified="2025-08-27 11:39:41 +0200 CEST" file.permissions=0660
```
---
### Author:  [@chaos](https://forum.syncthing.net/u/chaos)
#### Post date: [August 5, 2026, 4:11pm UTC](https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979/9 "2026-08-05T16:11:36Z")
I’d be interested to see the results of an Internet speed test (I use this one: [https://www.speedtest.net/](https://www.speedtest.net/)) both when connected via Ethernet cable and when connected via Wifi.
---
### Author:  [@Cheer1](https://forum.syncthing.net/u/Cheer1)
#### Post date: [August 5, 2026, 4:16pm UTC](https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979/10 "2026-08-05T16:16:29Z")
WiFi: [](https://www.speedtest.net/result/19520357894)
Ethernet: [](https://www.speedtest.net/result/19520367248)
---
### Author:  [@bt90](https://forum.syncthing.net/u/bt90)
#### Post date: [August 5, 2026, 5:53pm UTC](https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979/11 "2026-08-05T17:53:59Z")
Could you state the manufacturer and model of the wifi card?
---
### Author:  [@Cheer1](https://forum.syncthing.net/u/Cheer1)
#### Post date: [August 5, 2026, 6:08pm UTC](https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979/12 "2026-08-05T18:08:15Z")
```plaintext
lspci | grep -i network
03:00.0 Network controller: MEDIATEK Corp. MT7921 802.11ax PCI Express Wireless Network Adapter
```
My laptop is Thinkpad T14 Gen 1 Ryzen 7. I have had this laptop for a while and syncthing worked perfectly fine. I’m 99% sure it’s a software issue.
When my phone downloads something, it can still use internet with high-speed. When my laptop downloads something from the phone, it cannot.
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### Author:  [@calmh](https://forum.syncthing.net/u/calmh)
#### Post date: [August 5, 2026, 6:38pm UTC](https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979/13 "2026-08-05T18:38:23Z")
This is a bizarre thing. Syncthing effectively just opens a couple of TCP connections. 🤷
---
### Author:  [@mraneri](https://forum.syncthing.net/u/mraneri)
#### Post date: [August 5, 2026, 6:40pm UTC](https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979/14 "2026-08-05T18:40:47Z")
Agree this is really weird. There’s plenty of bandwidth available. And syncthing isn’t using any kind of low level network magic that should break stuff.
---
### Author:  [@Cheer1](https://forum.syncthing.net/u/Cheer1)
#### Post date: [August 5, 2026, 6:42pm UTC](https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979/15 "2026-08-05T18:42:26Z")
Is it plausible that syncthing is not at fault but my Debian Linux is?
Edit: I did check ping and connectivity between devices, so I don’t know. Maybe it’s the BasicSync fork for android? Ever since I switched to it this happens (though I changed phones at exactly the same time).
---
### Author:  [@Nummer378](https://forum.syncthing.net/u/Nummer378)
#### Post date: [August 5, 2026, 7:59pm UTC](https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979/16 "2026-08-05T19:59:07Z")
I would check `dmesg` on the Debian box to see if something in the network stack goes haywire during a sync. The other thing to verify is that there’s no insane amount of connections open or stuck on the system (for whatever reason) i.e. using `ss -s`.
---
### Author:  [@Cheer1](https://forum.syncthing.net/u/Cheer1)
#### Post date: [August 10, 2026, 12:00pm UTC](https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979/17 "2026-08-10T12:00:16Z")
Hi, I’m still struggling to get the right setup. Can someone please have a look at my connection options? I want to make sure everything is right on this level before delving deeper.
I use `tcp4` because IPv6 addresses are dynamic and it causes unstable connections. I enabled Global Discovery and Relaying in order to sync my files _on any other network that is not my LAN_, did not set a limit of bandwidth in LAN because there is a lot of bandwidth available.
In the Device \> Advanced I set “dynamic” assuming that if the peers don’t successfully connect via `tcp4` they will connect in any other way. Is this how it works? I tried to set the number of connections to 1 but that didn’t help, so I changed it back to 0.
Settings \> Connections
 
Device \> Advanced
 
---
### Author:  [@system](https://forum.syncthing.net/u/system)
#### Post date: [September 9, 2026, 12:00pm UTC](https://forum.syncthing.net/t/web-browsing-dns-stalls-completely-during-active-tcp-lan-sync-debian-pixel-8/26979/18 "2026-09-09T12:00:55Z")
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