我已经将我的 IP 地址添加到了/etc/hosts.allow并检查了fail2ban 是否禁止了我的 IP 地址。我还检查了 sshd_config 文件的 MaxStartups 是否太小，但事实并非如此。当我检查时，
tail -f /var/log/auth.log
我可以看到 Connection Reset by XXX.XXX.X.XXX port 3000 [preauth] 行。
但在我的笔记本电脑（客户端）中，连接立即停止，并显示消息 kex_exchange_identification：read：连接由对等方重置。
有人可以帮我解决这个问题吗？我在这上面花了足足三个小时……
+)ssh -vvv显示如下：
OpenSSH_8.1p1, LibreSSL 2.7.3 \
debug1: Reading configuration data /etc/ssh/ssh_config \
debug1: /etc/ssh/ssh_config line 47: Applying options for * \
debug2: resolve_canonicalize: hostname XXX.XXX.XX.XX is address \
debug2: ssh_connect_direct \
debug1: Connecting to XXX.XXX.XX.XX [XXX.XXX.XX.XX] port 22. \
debug1: Connection established. \
debug1: identity file /Users/sueyeon/.ssh/id_rsa type -1 \
debug1: identity file /Users/sueyeon/.ssh/id_rsa-cert type -1 \
debug1: identity file /Users/sueyeon/.ssh/id_dsa type -1 \
debug1: identity file /Users/sueyeon/.ssh/id_dsa-cert type -1 \
debug1: identity file /Users/sueyeon/.ssh/id_ecdsa type -1 \
debug1: identity file /Users/sueyeon/.ssh/id_ecdsa-cert type -1 \
debug1: identity file /Users/sueyeon/.ssh/id_ed25519 type -1 \
debug1: identity file /Users/sueyeon/.ssh/id_ed25519-cert type -1 \
debug1: identity file /Users/sueyeon/.ssh/id_xmss type -1 \
debug1: identity file /Users/sueyeon/.ssh/id_xmss-cert type -1 \
debug1: Local version string SSH-2.0-OpenSSH_8.1 \
kex_exchange_identification: read: Connection reset by peer
+) 有人告诉我 ssh 不再使用 dsa 密钥（例如 id_dsa）（由于 dsa 加密方案遭到破坏）。您的服务器可能会收到密钥并自动关闭连接。
解决这个问题的办法是什么？
我使用的是 Ubuntu 20.04.2，我的笔记本电脑（客户端）是 macOS Catalina 10.15.7