我使用的是 Ubuntu 22，SSH 处于活动状态。UFW 处于非活动状态。我有一个密钥对，并且已将 pub 存储在服务器上authorized_keys。我的另一台计算机上已经有密钥了。我在我的私有网络中。从这个网络，我可以通过 SSH 使用我的旧计算机访问服务器。
因此，您可能会认为所有设置都正确。特别是因为 SSH 的基本设置相对来说不言自明，而且作为初学者，我从未遇到过建立 SSH 连接的问题。
笔记：我可以使用相同的公钥访问我的 GitHub 帐户。因此密钥和我的 SSH 都可以正常工作。
问题：还有什么原因可能导致此错误？
SSH-vvvv[电子邮件保护]输出
OpenSSH_8.9p1 Ubuntu-3ubuntu0.6, OpenSSL 3.0.2 15 Mar 2022
debug1: Reading configuration data /home/me/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: include /etc/ssh/ssh_config.d/*.conf matched no files
debug1: /etc/ssh/ssh_config line 21: Applying options for *
debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts' -> '/home/me/.ssh/known_hosts'
debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts2' -> '/home/me/.ssh/known_hosts2'
debug2: resolving "xxx.yyy.com" port 22
debug3: resolve_host: lookup xxx.yyy.com:22
debug3: ssh_connect_direct: entering
debug1: Connecting to xxx.yyy.com [1.1.1.1] port 22.
debug3: set_sock_tos: set socket 3 IP_TOS 0x10
debug1: connect to address 1.1.1.1 port 22: Connection refused
ssh: connect to host xxx.yyy.com port 22: Connection refused
输出：systemctl status sshd.service
● ssh.service - OpenBSD Secure Shell server
Loaded: loaded (/lib/systemd/system/ssh.service; enabled; vendor preset: e>
Active: active (running) since Fri 2024-03-08 09:51:37 CET; 4h 42min ago
Docs: man:sshd(8)
man:sshd_config(5)
Main PID: 2847372 (sshd)
Tasks: 1 (limit: 18688)
Memory: 1.7M
CPU: 13ms
CGroup: /system.slice/ssh.service
└─2847372 "sshd: /usr/sbin/sshd -D [listener] 0 of 10-100 startups"
Mär 08 09:51:37 ttsbnb50 systemd[1]: Starting OpenBSD Secure Shell server...
Mär 08 09:51:37 ttsbnb50 sshd[2847372]: Server listening on 0.0.0.0 port 22.
Mär 08 09:51:37 ttsbnb50 sshd[2847372]: Server listening on :: port 22.
Mär 08 09:51:37 ttsbnb50 systemd[1]: Started OpenBSD Secure Shell server.
输出：sudo netstat -anp | grep ssh
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 2847372/sshd: /usr/
tcp6 0 0 :::22 :::* LISTEN 2847372/sshd: /usr/
unix 2 [ ACC ] STREAM HÖRT 42144 4471/systemd /run/user/1000/gnupg/S.gpg-agent.ssh
unix 2 [ ACC ] STREAM HÖRT 43365 4493/gnome-keyring- /run/user/1000/keyring/ssh
unix 3 [ ] STREAM VERBUNDEN 16223127 2847372/sshd: /usr/
unix 2 [ ACC ] STREAM HÖRT 5563534 1563240/ssh-agent /run/user/1000/keyring/.ssh
输出：ls -la ~/.ssh来自无法连接到我的服务器的计算机
drwx------ 2 me me 4096 Mär 3 15:12 .
drwxr-x--- 32 me me 4096 Mär 8 14:42 ..
-rw-rw-r-- 1 me me 51 Dez 29 22:48 config
-rw------- 1 me me 464 Apr 18 2023 id_ed25519
-rw-r--r-- 1 me me 111 Apr 18 2023 id_ed25519.pub
-rw------- 1 me me 1784 Jan 8 10:27 known_hosts
输出：cat ~/.ssh/config
Host github.com
Hostname ssh.github.com
Port 443
输出：cat /etc/ssh/ssh_config | grep -v ^#
Include /etc/ssh/ssh_config.d/*.conf
Host *
SendEnv LANG LC_*
HashKnownHosts yes
GSSAPIAuthentication yes
输出：ls -la /etc/ssh
drwxr-xr-x 4 root root 4096 Mär 8 09:51 .
drwxr-xr-x 143 root root 12288 Mär 12 06:25 ..
-rw-r--r-- 1 root root 505426 Jan 2 17:54 moduli
-rw-r--r-- 1 root root 1650 Nov 23 2022 ssh_config
drwxr-xr-x 2 root root 4096 Nov 23 2022 ssh_config.d
-rw-r--r-- 1 root root 3254 Jan 2 17:54 sshd_config
drwxr-xr-x 2 root root 4096 Jan 2 17:54 sshd_config.d
-rw------- 1 root root 505 Mär 8 09:51 ssh_host_ecdsa_key
-rw-r--r-- 1 root root 175 Mär 8 09:51 ssh_host_ecdsa_key.pub
-rw------- 1 root root 399 Mär 8 09:51 ssh_host_ed25519_key
-rw-r--r-- 1 root root 95 Mär 8 09:51 ssh_host_ed25519_key.pub
-rw------- 1 root root 2602 Mär 8 09:51 ssh_host_rsa_key
-rw-r--r-- 1 root root 567 Mär 8 09:51 ssh_host_rsa_key.pub
-rw-r--r-- 1 root root 342 Dez 7 2020 ssh_import_id
输出：cat /etc/ssh/ssh_config
Host *
# ForwardAgent no
# ForwardX11 no
# ForwardX11Trusted yes
# PasswordAuthentication yes
# HostbasedAuthentication no
# GSSAPIAuthentication no
# GSSAPIDelegateCredentials no
# GSSAPIKeyExchange no
# GSSAPITrustDNS no
# BatchMode no
# CheckHostIP yes
# AddressFamily any
# ConnectTimeout 0
# StrictHostKeyChecking ask
# IdentityFile ~/.ssh/id_rsa
# IdentityFile ~/.ssh/id_dsa
# IdentityFile ~/.ssh/id_ecdsa
# IdentityFile ~/.ssh/id_ed25519
# Port 22
# Ciphers aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc
# MACs hmac-md5,hmac-sha1,[email protected]
# EscapeChar ~
# Tunnel no
# TunnelDevice any:any
# PermitLocalCommand no
# VisualHostKey no
# ProxyCommand ssh -q -W %h:%p gateway.example.com
# RekeyLimit 1G 1h
# UserKnownHostsFile ~/.ssh/known_hosts.d/%k
SendEnv LANG LC_*
HashKnownHosts yes
GSSAPIAuthentication yes