怎样用一台本地主机ssh免密码登陆多台远程服务器

ssh登录远程服务器一般有密码验证和免输入密码的密钥验证两种方式。

都知道使用密钥登陆的话是需要生成一对密钥，然后将公钥放在服务器上.ssh/authorized_keys文件中，如果有多人登陆的话，将多人的id_rsa.pub文件中公钥内容按行全部放入该文件中就行了。本地主机登陆的时候会首先读取ssh客户端配置内容，然后找到私钥id_rsa文件，进行配对，过程如下：

debug1: Authenticating to xx.xx.xx.xx:22 as 'username'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: curve25519-sha256@libssh.org
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:3b9yRpz12sKEd46UZUnlr5thICYoj/fIkpjkaBk0UKI
debug1: Host 'xx.xx.xx.xx' is know