我曾经使用 ssh 密钥正常连接到 digitalocean 上的网站，并且工作正常。目前我尝试连接，突然我不断收到：ssh_exchange_identification: read: Operation timed out。
我尝试再次运行 ssh 命令-vvv，得到以下结果：
OpenSSH_6.9p1, LibreSSL 2.1.8
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 20: Applying options for *
debug1: /etc/ssh/ssh_config line 102: Applying options for *
debug1: Connecting to ip [ip] port 22.
debug1: Connection established.
debug1: identity file /Users/safwany/.ssh/id_rsa type 1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/safwany/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/safwany/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/safwany/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/safwany/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/safwany/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/safwany/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/safwany/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.9
ssh_exchange_identification: read: Operation timed out
知道造成此类错误的原因是什么以及如何修复它吗？
更新：我跑了ls -al ~/.ssh并得到以下信息：
total 160
drwx------ 15 safwany staff 510 Jul 12 23:52 .
drwx------+ 109 safwany staff 3706 Jul 13 00:02 ..
-rwx------ 1 safwany staff 2437 Jul 13 00:02 authorized_keys
-rw------- 1 safwany staff 1679 Mar 17 2015 digitalocean
-rw-r--r-- 1 safwany staff 413 Mar 17 2015 digitalocean.pub
-rw------- 1 safwany staff 1679 Mar 4 2015 fortrabbit
-rw-r--r-- 1 safwany staff 413 Mar 4 2015 fortrabbit.pub
-rwx------ 1 safwany staff 1766 Nov 21 2014 github_rsa
-rwx------ 1 safwany staff 404 Nov 21 2014 github_rsa.pub
-rw------- 1 safwany staff 1675 Jul 1 2015 id_boot2docker
-rw-r--r-- 1 safwany staff 413 Jul 1 2015 id_boot2docker.pub
-rw------- 1 safwany staff 1675 Nov 23 2014 id_rsa
-rw------- 1 safwany staff 381 Jul 12 23:16 id_rsa.pub
-rw------- 1 safwany staff 17736 Jul 10 17:11 known_hosts
-rw------- 1 safwany staff 15268 Feb 21 22:44 known_hosts.old