我正尝试使用SSH连接到AWS服务器，但不知何故无法连接。当我运行以下命令时：
ssh -i <keypair.pem> ec2-user@<ip> -vvv
返回信息如下：
OpenSSH_7.6p1 Ubuntu-4, OpenSSL 1.0.2n 7 Dec 2017
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug2: resolving "<ip>" port 22
debug2: ssh_connect_direct: needpriv 0
debug1: Connecting to <ip> [<ip>] port 22.
debug1: Connection established.
debug1: key_load_public: No such file or directory
debug1: identity file <keypair.pem> type -1
debug1: key_load_public: No such file or directory
debug1: identity file <keypair.pem>-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_7.6p1 Ubuntu-4
我猜测这是路由器IP禁止配置问题？我该怎么办？