Sync problem: "0 addresses found from DNS seeds"

Support and Troubleshooting
1

Hello, Umbrel community.

My Umbrel node had been working perfectly fine, until 13 days ago I started to have an issue syncronizing Bitcoin Core on my Raspberry Pi 4 Model B Rev 1.4 (Umbrel version 0.4.17).
As far as I understood from log-file, Bitcoin Core is not able to read seeds to start sync from. The Umbrel node is located in Russia. Is it possible that Russian ISP blocked seed list addresses? Like it happened in Iran? And what could be a solution for that problem?

2022-04-23 13.31.34
2022-04-23 13.31.34935×1102 83.5 KB

Bitcoin Core logs

Attaching to bitcoin
bitcoin | 2022-04-23T09:25:13Z Loaded 68017 addresses from peers.dat 1449ms
bitcoin | 2022-04-23T09:25:14Z Loaded 0 addresses from “anchors.dat”
bitcoin | 2022-04-23T09:25:14Z 0 block-relay-only anchors will be tried for connections.
bitcoin | 2022-04-23T09:25:14Z init message: Starting network threads…
bitcoin | 2022-04-23T09:25:14Z net thread start
bitcoin | 2022-04-23T09:25:14Z dnsseed thread start
bitcoin | 2022-04-23T09:25:14Z Waiting 300 seconds before querying DNS seeds.
bitcoin | 2022-04-23T09:25:14Z opencon thread start
bitcoin | 2022-04-23T09:25:14Z addcon thread start
bitcoin | 2022-04-23T09:25:14Z msghand thread start
bitcoin | 2022-04-23T09:25:14Z init message: Done loading
bitcoin | 2022-04-23T09:26:49Z Imported mempool transactions from disk: 1778 succeeded, 0 failed, 0 expired, 0 already there, 0 waiting for initial broadcast
bitcoin | 2022-04-23T09:26:49Z loadblk thread exit
bitcoin | 2022-04-23T09:30:14Z Loading addresses from DNS seed seed. bitcoinstats. com
bitcoin | 2022-04-23T09:30:14Z Loading addresses from DNS seed dnsseed. emzy. de
bitcoin | 2022-04-23T09:30:14Z Loading addresses from DNS seed seed. bitcoin. sipa. be
bitcoin | 2022-04-23T09:30:14Z Waiting 300 seconds before querying DNS seeds.
bitcoin | 2022-04-23T09:35:14Z Loading addresses from DNS seed seed. bitcoin. sprovoost. nl
bitcoin | 2022-04-23T09:35:14Z Loading addresses from DNS seed seed. bitcoin. jonasschnelli. ch
bitcoin | 2022-04-23T09:35:14Z Loading addresses from DNS seed dnsseed. bitcoin. dashjr. org
bitcoin | 2022-04-23T09:35:14Z Waiting 300 seconds before querying DNS seeds.
bitcoin | 2022-04-23T09:40:14Z Loading addresses from DNS seed seed. btc. petertodd. org
bitcoin | 2022-04-23T09:40:14Z Loading addresses from DNS seed seed. bitcoin. wiz. biz
bitcoin | 2022-04-23T09:40:14Z Loading addresses from DNS seed dnsseed. bluematt. me
bitcoin | 2022-04-23T09:40:14Z 0 addresses found from DNS seeds
bitcoin | 2022-04-23T09:40:14Z dnsseed thread exit
bitcoin | 2022-04-23T09:52:12Z Potential stale tip detected, will try using extra outbound peer (last tip update: 1904 seconds ago)
bitcoin | 2022-04-23T10:02:42Z Potential stale tip detected, will try using extra outbound peer (last tip update: 2534 seconds ago)
bitcoin | 2022-04-23T10:13:13Z Potential stale tip detected, will try using extra outbound peer (last tip update: 3165 seconds ago)
bitcoin | 2022-04-23T10:23:43Z Potential stale tip detected, will try using extra outbound peer (last tip update: 3795 seconds ago)

2

Hmmm, very interesting case.
Indeed could be that those servers are blocked some way.
But strange thing is that Umbrel is behind Tor so it should take/ read the Tor servers too even if the clearnet are not reachable.

You could try adding manually a bunch of well known IP/server addresses for BTC nodes, even Tor onion addresses. Could be from any other BTC node, not specifically public ones.
Edit the bitcoin.conf

If you have another friend node runner in Russia, you could add his onion node in that list for sync so your node will point directly to his.

In your new node, use the following command to connect to existing running node and sync the blockchain data directly, on the fly.
Enter SSH into your new Umbrel node, then:
cd umbrel
sudo docker exec bitcoin bitcoin-cli addnode "192.168.x.x:8333" "onetry"
replace “192.168.x.x” with your friend running node IP/onion address/clearnet address.

This will make your new node to sync directly from your old running node, without need to be connected to internet, if you have a slow connection or Tor is making problems.
Once is finished, you can remove the IP from peers and go back to normal connection.

More details here

3

Running command “nslookup” with those adresses returns a fixed list of IPs here.

4

Update:

  • I tried to manually add IP/server addresses for BTC nodes as you suggested here - did not help.

  • Took my Umbrel node to another location with another ISP - did not help.

  • Downloaded Bitcoin Core 22.0 from the official site and started syncing on my Linux laptop via the same router where the node is connected - syncs well.

So, the problem is not in my ISP or internet connection. Probably, node itself (HW or SW).

  • So, I reflashed Umbrel SD-card with freshly downloaded Umbrel image 0.4.17 - did not help.

  • Updated Umbrel to 0.5.0 - did not help.

  • Exchanged HDD of my node - did not help.

So for now it appeares that a completely renewed node does not sync from the initial startup.

  • So, I downloaded Umbrel 0.5.0 and started setup on my Linux laptop.

  • Now I can use my Umbrel node on Linux laptop only. Still do not know how to solve this issue on Raspberry Pi node :frowning:

5

Update:
Just occasionaly have decided to try syncing Umbrel 0.4.17 ones again and … it worked! I do not know what happened exactly… :man_shrugging:

So I am happy my Umbrel Node rejoined the network! Updated to 0.5.3 successfully btw