Just search for:
It will get some answer, for example: Ssh issues - #2 by LupusE
[…]
One time:
ssh -oHostKeyAlgorithms=+ssh-rsa root@192.168.8.1
Permanent:
echo -e “\tHostKeyAlgorithms ssh-rsa” >> .ssh/config
[…]
The error says “I ask for a set of ‘key types’, none is okay for the host. It demands ssh-rsa”. And oHostKeyAlgorithms=+ssh-rsa adds this ‘type’ to the offered choices.