fail to ssh remote host with error message "Permission denied (publickey)" - public-key

Question

Recently,I meet problem with ssh remote host.
At first,I can ssh the remote host when the "PasswordAuthentication" parameter is "yes" in the /etc/ssh/sshd_config file.
However,after I changing the "PasswordAuthentication" parameter to "no" in the /etc/ssh/sshd_config file,I fail to ssh remote host.
I know my problem is about PublicKey,because I have these parameters in my /etc/ssh/sshd_config file:
RSAAuthentication yes
PubkeyAuthentication yes
PermitRootLogin yes
The result of "# ssh root#172.17.4.17 -VVV" looks like that,
debug1: Server host key: RSA 8a:bb:7f:d0:61:69:cc:b2:a1:a0:16:be:52:c1:5c:94
debug3: load_hostkeys: loading entries for host "172.17.4.17" from file "/home/jundu/.ssh/known_hosts"
debug3: load_hostkeys: found key type RSA in file /home/jundu/.ssh/known_hosts:12
debug3: load_hostkeys: loaded 1 keys
debug1: Host '172.17.4.17' is known and matches the RSA host key.
debug1: Found key in /home/jundu/.ssh/known_hosts:12
debug1: ssh_rsa_verify: signature correct
debug2: kex_derive_keys
debug2: set_newkeys: mode 1
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug2: set_newkeys: mode 0
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: /home/jundu/.ssh/id_rsa ((nil))
debug2: key: /home/jundu/.ssh/id_dsa ((nil))
debug2: key: /home/jundu/.ssh/id_ecdsa ((nil))
debug1: Authentications that can continue: publickey
debug3: start over, passed a different list publickey
debug3: preferred gssapi-keyex,gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /home/jundu/.ssh/id_rsa
debug3: no such identity: /home/jundu/.ssh/id_rsa
debug1: Trying private key: /home/jundu/.ssh/id_dsa
debug3: no such identity: /home/jundu/.ssh/id_dsa
debug1: Trying private key: /home/jundu/.ssh/id_ecdsa
debug3: no such identity: /home/jundu/.ssh/id_ecdsa
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
Permission denied (publickey).
Permission denied (publickey)?I just don't know what does it mean.Can anyone provide me with some suggestions?Thank you in advance!

Answer 1

In some cases of using ssh, when we meet the issues about Permission denied (publickey)?, it means two things:
1) we are using ssh key-pairs to access remote host.
2) we never let remote host know our local host's public key and don't have a private key to access.
Solutions:
step1: copy a public key to remote host(usually in ~/.ssh/authorized_key)
step2: paste the corresponding private key in local host's ~/.ssh/id_rsa(or id_dsa)