Stuck at startimg umbrel screen + POSSIBLE DNS SPOOFING DETECTED

Support and Troubleshooting
1

Hi all,

I’ve have been havig problems with my node latelly. A few weeks ago It suddenly stopped working and I could not acces Umbrel any more. Since then I have:

· Cleaned SD from both Umbrel + Raspbian and reinstalled everyting again: no luck.
· Tried with umbrel 3.0 version: no luck.
· Changed the power cable in the raspberry: no luck.
· Even deleted and cleaned the external hard dics (despite I know i have to download the whole blockchain again…): no luck.

The last message I gof from my node, after connecting trough ssh, was:

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
The ECDSA host key for umbrel.local has changed,
and the key for the corresponding IP address fe80::860e:8ba4:aeb9:114b%18
is unknown. This could either mean that
DNS SPOOFING is happening or the IP address for the host
and its host key have changed at the same time.
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the ECDSA key sent by the remote host is
SHA256:iGRd2F7K8hJjvNztiBIziAJ2izns0kiTcntyKqSCoTU.
Please contact your system administrator.
Add correct host key in C:\Users\mares/.ssh/known_hosts to get rid of this message.
Offending ECDSA key in C:\Users\mares/.ssh/known_hosts:1
ECDSA host key for umbrel.local has changed and you have requested strict checking.
Host key verification failed.

This is a huge mess, and I have spent lots of hours now on that. I might buy all the new hardware and start from scracth.

Any one could suggest something? Thanks!

2

Do not buy new hardware

Go to this community forum and you will find the answer you are looking for.

Basically what happened is, when you first secure-shelled into umbrel you typed ‘yes’ to a question. That question asked if you wanted to add umbrel to your computer’s list of known hosts. Now that you reflashed umbrel your computer sees a dif file and thinks something is up. I had the same issue.

I am on a Mac computer, so not sure about Windows (if different), but you need to remove umbrel from your known host file. Just go into terminal/powershell (of your comp, not umbrel) and type:

nano ~/.ssh/known_hosts

That will bring you to a primitive looking text editor that looks like this:

Screen Shot 2021-09-02 at 12.38.57 PM
Screen Shot 2021-09-02 at 12.38.57 PM2850×1728 199 KB

Delete all of the text in the umbrel.local section, and then press control+x to exit and then y when it asks you to save, and then enter key.

You can now ssh back into your umbrel because you don’t have a conflicting known host file.

1 Like
3

Hi, cam.

Thanks for your help.

I finnaly could manage to acces the node again, wich was a relief. However now I am even moren scared as I do not see my previous btc I had there in order to run LN. I had to erase all the external disc, as I think the problem was coming from there, so I have to download again all the blockchain. I hope to see, once is all downloaed, my funs again.

Thanks anyway.