ssh连接其他Linux机器过慢解决方法

ssh连接其他Linux机器过慢解决方法

豪门总裁 2015-04-04

ssh连接其他Linux机器过慢解决方法

分类: 豪门总裁时间: 2015-04-04

 ssh在连接其他Linux机器的时候,有时会出现这样的问题,虽然能够连接上,但连接速度很慢,非常消耗时间,下面未来小编就给大家介绍下ssh连接Linux机器过慢的解决方法。

  在局域网内,能ping通目标机器,并且时延是微秒级。

  用ssh连局域网内其他linux机器,会等待10-30秒才有提示输入密码。严重影响工作效率。

  CentOS修改后效果一样

  =================================

  客户端操作系统版本:

  cat /etc/lsb-release

  DISTRIB_ID=Ubuntu

  DISTRIB_RELEASE=9.10

  DISTRIB_CODENAME=karmic

  DISTRIB_DESCRIPTION=“Ubuntu 9.10”0

  =================================

  调试信息:

  [root@IBM ~]# ssh -v 10.10.10.100

  OpenSSH_3.9p1, OpenSSL 0.9.7a Feb 19 2003

  debug1: Reading configuration data /etc/ssh/ssh_config

  debug1: Applying options for *

  debug1: Connecting to 10.10.10.100 [10.10.10.100] port 22.

  debug1: connect to address 10.10.10.100 port 22: Connection refused

  ssh: connect to host 10.10.10.100 port 22: Connection refused

  ----------------[网络上的调试信息]----------------------

  ssh -v 192.168.12.16

  OpenSSH_5.1p1 Debian-6ubuntu2, OpenSSL 0.9.8g 19 Oct 2007

  debug1: Reading configuration data /etc/ssh/ssh_config

  debug1: Applying options for *

  debug1: Connecting to 192.168.12.16 [192.168.12.16] port 22.

  debug1: Connection established.

  debug1: identity file /home/zhouhh/.ssh/identity type -1

  debug1: identity file /home/zhouhh/.ssh/id_rsa type -1

  debug1: identity file /home/zhouhh/.ssh/id_dsa type -1

  debug1: Remote protocol version 2.0, remote software version OpenSSH_4.3

  debug1: match: OpenSSH_4.3 pat OpenSSH_4*

  debug1: Enabling compatibility mode for protocol 2.0

  debug1: Local version string SSH-2.0-OpenSSH_5.1p1 Debian-6ubuntu2

  debug1: SSH2_MSG_KEXINIT sent

  debug1: SSH2_MSG_KEXINIT received

  debug1: kex: server-》client aes128-cbc hmac-md5 none

  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

  debug1: SSH2_MSG_KEX_DH_GEX_INIT sent

  debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY

  debug1: Host ‘192.168.12.16’ is known and matches the RSA host key.

  debug1: Found key in /home/zhouhh/.ssh/known_hosts:1

  debug1: ssh_rsa_verify: signature correct

  debug1: SSH2_MSG_NEWKEYS sent

  debug1: expecting SSH2_MSG_NEWKEYS

  debug1: SSH2_MSG_NEWKEYS received

  debug1: SSH2_MSG_SERVICE_REQUEST sent

  debug1: SSH2_MSG_SERVICE_ACCEPT received

  debug1: Authentications that can continue: publickey,gssapi-with-mic,password

  debug1: Next authentication method: gssapi-with-mic

  debug1: An invalid name was supplied

  Cannot determine realm for numeric host address

  debug1: An invalid name was supplied

  Cannot determine realm for numeric host address

  debug1: An invalid name was supplied

  debug1: Next authentication method: publickey

  debug1: Trying private key: /home/zhouhh/.ssh/identity

  debug1: Trying private key: /home/zhouhh/.ssh/id_rsa

  debug1: Trying private key: /home/zhouhh/.ssh/id_dsa

  debug1: Next authentication method: password

  password:

  debug1: Authentication succeeded (password)。

  debug1: channel 0: new [client-session]

  debug1: Entering interactive session.

  debug1: Sending environment.

  debug1: Sending env LANG = zh_CN.UTF-8

  Last login: Fri Dec 25 13:35:04 2009 from 192.168.11.146
可以看到如下的错误信息:

  debug1: Next authentication method: gssapi-with-mic

  debug1: An invalid name was supplied

  Cannot determine realm for numeric host address

  事实上,正是从gssapi-with-mic这一行开始,开始耗时间。

  失败的尝试:

  有人说是在目标机器中修改/etc/ssh/sshd_conf文件

  将UseDNS 的缺省值由yes修改为no,并重启sshd。我试了,对这种情况不管用。但不排除对别的延迟情况管用。

  ====================

  有效的解决办法:

  1、修改本地机器的hosts文件,将目标机器的IP和域名加上去。或者让本机的DNS 服务器能解析目标地址。

  vi /etc/hosts

  192.168.12.16 ourdev

  其格式是“目标机器IP 目标机器名称”这种方法促效。没有延迟就连上了。不过如果给每台都加一个域名解析,挺辛苦的。但在windows下用putty或secure-crt时可以采用这种方法。

  2、修改本机的客户端配置文件ssh_conf,注意,不是sshd_conf

  vi /etc/ssh/ssh_conf

  找到

  GSSAPIAuthentication yes

  改为

  GSSAPIAuthentication no

  保存。

  再连目标机器,速度就飞快了。

  GSSAPI ( Generic Security Services Application Programming Interface) 是一套类似Kerberos 5 的通用网络安全系统接口。该接口是对各种不同的客户端服务器安全机制的封装,以消除安全接口的不同,降低编程难度。但该接口在目标机器无域名解析时会有问题。我看到有人给Ubuntu提交了相关bug, 说要将GSSAPIAuthentication的缺省值设为no,不知为何,ubuntu9.10的缺省值还是yes。

  修改完毕,此时的连接调试数据变为了:

  view plaincopy to clipboardprint?

  ssh -v 192.168.12.16

  OpenSSH_5.1p1 Debian-6ubuntu2, OpenSSL 0.9.8g 19 Oct 2007

  debug1: Reading configuration data /etc/ssh/ssh_config

  debug1: Applying options for *

  debug1: Connecting to 192.168.12.16 [192.168.12.16] port 22.

  debug1: Connection established.

  debug1: identity file /home/zhouhh/.ssh/identity type -1

  debug1: identity file /home/zhouhh/.ssh/id_rsa type -1

  debug1: identity file /home/zhouhh/.ssh/id_dsa type -1

  debug1: Remote protocol version 2.0, remote software version OpenSSH_4.3

  debug1: match: OpenSSH_4.3 pat OpenSSH_4*

  debug1: Enabling compatibility mode for protocol 2.0

  debug1: Local version string SSH-2.0-OpenSSH_5.1p1 Debian-6ubuntu2

  debug1: SSH2_MSG_KEXINIT sent

  debug1: SSH2_MSG_KEXINIT received

  debug1: kex: server-》client aes128-cbc hmac-md5 none

  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

  debug1: SSH2_MSG_KEX_DH_GEX_INIT sent

  debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY

  debug1: Host ‘192.168.12.16’ is known and matches the RSA host key.

  debug1: Found key in /home/zhouhh/.ssh/known_hosts:1

  debug1: ssh_rsa_verify: signature correct

  debug1: SSH2_MSG_NEWKEYS sent

  debug1: expecting SSH2_MSG_NEWKEYS

  debug1: SSH2_MSG_NEWKEYS received

  debug1: SSH2_MSG_SERVICE_REQUEST sent

  debug1: SSH2_MSG_SERVICE_ACCEPT received

  debug1: Authentications that can continue: publickey,gssapi-with-mic,password

  debug1: Next authentication method: publickey

  debug1: Trying private key: /home/zhouhh/.ssh/identity

  debug1: Trying private key: /home/zhouhh/.ssh/id_rsa

  debug1: Trying private key: /home/zhouhh/.ssh/id_dsa

  debug1: Next authentication method: password

  password: