我有一个远程CentOS服务器，我有SSH访问。 今天，当我尝试通过SSHlogin时，即使使用了正确的凭据，我也只能获得拒绝访问权限。 我有plesk 9访问权限，所以重置pipe理员密码，并试图使用该密码的SSH，但无济于事。 我甚至创build了一个具有SSH访问权限的新用户，并试图以他们的身份login，但同样的拒绝访问失败。 我已经重新启动。
任何人可以提供任何build议？ 在plesk中没有文件pipe理器，除了networking域，所以我不能在任何系统文件中看到发生了什么。
任何意见赞赏。
编辑————-输出要求Iain
OpenSSH_4.7p1 Debian-8ubuntu1.2, OpenSSL 0.9.8g 19 Oct 2007 debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug2: ssh_connect: needpriv 0 debug1: Connecting to XXXXX [XXXXX] port 22. debug1: Connection established. debug1: permanently_set_uid: 0/0 debug1: identity file /root/.ssh/identity type -1 debug1: identity file /root/.ssh/id_rsa type -1 debug1: identity file /root/.ssh/id_dsa type -1 debug1: Remote protocol version 2.0, remote software version OpenSSH_4.3 debug1: match: OpenSSH_4.3 pat OpenSSH* debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_4.7p1 Debian-8ubuntu1.2 debug2: fd 3 setting O_NONBLOCK debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-g roup-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1 debug2: kex_parse_kexinit: ssh-rsa,ssh-dss debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour1 28,arcfour256,arcfour,aes192-cbc,aes256-cbc,[email protected],aes128-c tr,aes192-ctr,aes256-ctr debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour1 28,arcfour256,arcfour,aes192-cbc,aes256-cbc,[email protected],aes128-c tr,aes192-ctr,aes256-ctr debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-ripemd160 ,[email protected],hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-ripemd160 ,[email protected],hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: none,[email protected],zlib debug2: kex_parse_kexinit: none,[email protected],zlib debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: first_kex_follows 0 debug2: kex_parse_kexinit: reserved 0 debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha1,diffie-hellman-gro up14-sha1,diffie-hellman-group1-sha1 debug2: kex_parse_kexinit: ssh-rsa,ssh-dss debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour1 28,arcfour256,arcfour,aes192-cbc,aes256-cbc,[email protected],aes128-c tr,aes192-ctr,aes256-ctr debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour1 28,arcfour256,arcfour,aes192-cbc,aes256-cbc,[email protected],aes128-c tr,aes192-ctr,aes256-ctr debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@open ssh.com,hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@open ssh.com,hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: none,[email protected] debug2: kex_parse_kexinit: none,[email protected] debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: first_kex_follows 0 debug2: kex_parse_kexinit: reserved 0 debug2: mac_setup: found hmac-md5 debug1: kex: server->client aes128-cbc hmac-md5 none debug2: mac_setup: found hmac-md5 debug1: kex: client->server aes128-cbc hmac-md5 none debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP debug2: dh_gen_key: priv key bits set: 122/256 debug2: bits set: 507/1024 debug1: SSH2_MSG_KEX_DH_GEX_INIT sent debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY debug3: check_host_in_hostfile: filename /root/.ssh/known_hosts debug3: check_host_in_hostfile: filename /etc/ssh/ssh_known_hosts debug3: check_host_in_hostfile: filename /root/.ssh/known_hosts debug3: check_host_in_hostfile: match line 1 debug3: check_host_in_hostfile: filename /root/.ssh/known_hosts debug3: check_host_in_hostfile: filename /etc/ssh/ssh_known_hosts debug2: no key of type 0 for host XXXXX debug3: check_host_in_hostfile: filename /root/.ssh/known_hosts2 debug3: check_host_in_hostfile: filename /etc/ssh/ssh_known_hosts2 debug3: check_host_in_hostfile: filename /root/.ssh/known_hosts debug3: check_host_in_hostfile: filename /etc/ssh/ssh_known_hosts debug2: no key of type 2 for host XXXXX The authenticity of host 'XXXXX (XXXXX)' can 't be established. RSA key fingerprint is da:23:25:e5:e7:11:7f:73:f3:d2:be:a4:f8:b9:a7:21. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added 'XXXXX' (RSA) to the list of known hosts. debug2: bits set: 491/1024 debug1: ssh_rsa_verify: signature correct debug2: kex_derive_keys debug2: set_newkeys: mode 1 debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug2: set_newkeys: mode 0 debug1: SSH2_MSG_NEWKEYS received debug1: SSH2_MSG_SERVICE_REQUEST sent debug2: service_accept: ssh-userauth debug1: SSH2_MSG_SERVICE_ACCEPT received debug2: key: /root/.ssh/identity ((nil)) debug2: key: /root/.ssh/id_rsa ((nil)) debug2: key: /root/.ssh/id_dsa ((nil)) debug1: Authentications that can continue: publickey,gssapi-with-mic,password debug3: start over, passed a different list publickey,gssapi-with-mic,password debug3: preferred gssapi-keyex,gssapi-with-mic,gssapi,publickey,keyboard-interac tive,password debug3: authmethod_lookup gssapi-with-mic debug3: remaining preferred: gssapi,publickey,keyboard-interactive,password debug3: authmethod_is_enabled gssapi-with-mic debug1: Next authentication method: gssapi-with-mic debug1: Unspecified GSS failure. Minor code may provide more information No credentials cache found debug1: Unspecified GSS failure. Minor code may provide more information No credentials cache found debug1: Unspecified GSS failure. Minor code may provide more information debug2: we did not send a packet, disable method debug3: authmethod_lookup publickey debug3: remaining preferred: keyboard-interactive,password debug3: authmethod_is_enabled publickey debug1: Next authentication method: publickey debug1: Trying private key: /root/.ssh/identity debug3: no such identity: /root/.ssh/identity debug1: Trying private key: /root/.ssh/id_rsa debug3: no such identity: /root/.ssh/id_rsa debug1: Trying private key: /root/.ssh/id_dsa debug3: no such identity: /root/.ssh/id_dsa debug2: we did not send a packet, disable method debug3: authmethod_lookup password debug3: remaining preferred: ,password debug3: authmethod_is_enabled password debug1: Next authentication method: password root@XXXXX's password: debug3: packet_send2: adding 48 (len 62 padlen 18 extra_pad 64) debug2: we sent a password packet, wait for reply Connection closed by XXXXX 这几乎让我想起了一种情况，我已经看到你的空间不足，而且一个进程不能分叉，等等。如果空间不是问题，那么你会想看看你的账户是否被locking。
如果你可以运行远程命令，但不能看到输出，你应该尝试将输出传送给一个邮件程序来向你发送详细信息。 例如： cat /etc/ssh/sshd_config | mail -s ssh_config [email protected] cat /etc/ssh/sshd_config | mail -s ssh_config [email protected]
有一个很好的机会，你的sshd_config有以下设置：
PermitRootLogin without-password
这意味着，Root只能使用密钥进行身份validation。 如果您从未提供过一个，那么很可能您需要让您的数据中心将该框放到单用户模式并编辑该文件以允许您进入。
之后，制作私钥/公钥对，并在服务器上获取公钥，以便更安全地进行身份validation。
将AllowUsers检入/ etc / ssh / sshd_config。
除了已经给出的答案外，特别是Tim关于根账户特定设置的build议，让我添加一些关于快速诊断ssh连接问题的基本方法的基础知识。
在客户端上添加详细选项
ssh -vvv me@node
一个v意味着冗长，2 v意味着更冗长等等…
如果这还不够，在服务器上，如果你是唯一的用户（或者在凌晨3点;-)则停止sshd守护进程并使用完全debugging标志运行它。
sshd -ddd
同样的事情一个D代表debugging（简洁），2为更多的debugging等等…当公钥已被交换，这往往指向文件/文件夹的权限问题。