DNS Server failed to start

Help
1

Hello,

since today my pi-hole server random stopped working. This happen with a very old version months ago too. I completly reinstalled and everything was fine, until today. Can someone help me?

Actual Behaviour:

Random after the time.

Debug Token:

https://tricorder.pi-hole.net/5xa05oK3/

Thanks in advance!

2

Your debug log does not show any abnormalities.

Look in the following logs and see if there are any errors shown around the time that Pi-hole stopped working:

/var/log/syslog

/var/log/pihole-FTL.log

And in the ouput of the following command from the Pi terminal:

dmesg

I did note this in your debug log. Your DHCP server is providing three DNS servers, none of which appear to be your Pi-hole. How are clients finding the Pi-hole DNS if the DHCP server is not providing the IP? And on what type of device are you hosting the Pi-hole? Is this on a VPS outside your LAN or on a device within your LAN?

*** [ DIAGNOSING ]: Discovering active DHCP servers (takes 10 seconds)
   Scanning all your interfaces for DHCP servers
   Timeout: 10 seconds
   
   * Received 314 bytes from eth0:172.31.1.1
     Offered IP address: redacted
     Server IP address: redacted
     Relay-agent IP address: N/A
     BOOTP server: (empty)
     BOOTP file: /pxelinux.0
     DHCP options:
      Message type: DHCPOFFER (2)
      server-identifier: 172.31.1.1
      lease-time: 86400 ( 1d )
      netmask: 255.255.255.255
      router: 172.31.1.1
      dns-server: 213.133.99.99
      dns-server: 213.133.100.100
      dns-server: 213.133.98.98
         Microsoft Classless Static Route:
        1: 172.31.1.1/32 via 0.0.0.0
        2: default via 172.31.1.1
      --- end of options ---
    
   DHCP packets received on interface eth0: 1
   DHCP packets received on interface lo: 0
3

Hey,

it's a VPS server, hosted in a datacenter. That's very strange, I dont have DHCP activated on my pi-hole, because I dont need it.
syslog.zip (19.3 KB)
pihole-FTL.zip (398.4 KB)
dmesg.zip (10.8 KB)

Thanks in advance!

5

It appears you are running an open resolver. We do not condone nor support open resolvers.

image
image1261×560 105 KB

6

Sorry, I dont understand what you mean. I'm running the pi-hole for over one year. Can you tell me what I need to fix or what the problem is?

Thanks in advance!

7

Your Pi-hole instance is open to the internet via port 53. It is subject to being used in a variety of nefarious ways, including DDOS attacks.

https://www.ncsc.gov.ie/emailsfrom/DDoS/DNS/

Close port 53 to the internet.

9

I closed the port, but my pi-hole is still not working.
Screen: https://gyazo.com/67fa0bd3b15131253a4acabcba8337be

10

Please generate a fresh debug log and post the new token URL here.

11

Hello,

here is the debug token: https://tricorder.pi-hole.net/uz29yHKa/

13

Now that you have closed port 53, how are you accessing the Pi-hole?

14

From external not over the local address.

15

I don't understand. Please elaborate.

16

From the external website. http://78.47.99.226/

18

This is a URL that leads to the admin interface. How are your devices accessing Pi-hole for DNS over port 53?

19

You asked me how I access the pi-hole. I access it with the admin panel. I added in my router the dns server of the pi-hole.

20

If you are able to access the remote instance of Pi-hole this way, port 53 should still be open.

21

Oke, then I unblock the port 53. But I still dont know, why the dns server is not working. It just random stopped working from nowhere.

22

That's not what I am asking. You noted that port 53 is now blocked (which eliminates the open DNS resolver). But if this is the case, how are your clients accessing the remote Pi-hole for DNS on port 53? Are you using a VPN?

23

Yes, I blocked the port, because you told me to do it. Im not using a VPN. I setup in my router the dns server and the clients are connected to the router. Client <--> [intern] Router [extern] <--> DNS

24

Any other idea?