我在ssh配置方面遇到了麻烦。因为我有多个密钥对和多个主机，所以我想设置ssh配置文件，以便我可以轻松地在它们之间切换。
我的ssh配置文件如下：
Host blog
User Myusername
HostName github.com
IdentityFile ~/.ssh/macbook_id_rsa
Host blog2
User Myusername2
HostName github.com
IdentityFile ~/.ssh/macbook_2_id_rsa
现在，如果我使用ssh-add添加我的私钥并输入密码，则可以连接到Github或其他主机。但是当我尝试切换不同的密钥对时，就会遇到问题。
ssh -vT blog
我收到了如下错误消息：
OpenSSH_6.2p2, OSSLShim 0.9.8r 8 Dec 2011
debug1: Reading configuration data /Users/paul/.ssh/config
debug1: /Users/paul/.ssh/config line 1: Applying options for blog
debug1: Reading configuration data /etc/ssh_config
debug1: /etc/ssh_config line 20: Applying options for *
debug1: Connecting to github.com [192.30.252.130] port 22.
debug1: Connection established.
debug1: identity file /Users/paul/.ssh/macbook_id_rsa type 1
debug1: identity file /Users/paul/.ssh/macbook_id_rsa-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.2
debug1: Remote protocol version 2.0, remote software version libssh-0.7.0
debug1: no match: libssh-0.7.0
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-sha1 none
debug1: kex: client->server aes128-ctr hmac-sha1 none
debug1: sending SSH2_MSG_KEXDH_INIT
debug1: expecting SSH2_MSG_KEXDH_REPLY
debug1: Server host key: RSA 16:27:ac:a5:76:28:2d:36:63:1b:56:4d:eb:df:a6:48
debug1: Host 'github.com' is known and matches the RSA host key.
debug1: Found key in /Users/paul/.ssh/known_hosts:3
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /Users/paul/.ssh/macbook_id_rsa
debug1: Authentications that can continue: publickey
debug1: No more authentication methods to try.
Permission denied (publickey).
请问有人能够指出我的ssh配置是否有问题，或者我在这里漏掉了什么。谢谢。