现象：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 10.10.10.100OpenSSH_3.9p1, OpenSSL 0.9.7a Feb 19 2003debug1: Reading configuration data /etc/ssh/ssh_configdebug1: 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 refusedssh: 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-micdebug1: An invalid name was suppliedCannot 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。
人爱美，不仅需要服饰居室之美，还需要心灵品德之美。
