[SSH]putty超时解决方案[转载]
ssh 超时(ssh timeout) 解决办法转载自：yaozer博客来的ssh是不会超时的, 但是自从上次给ubuntu Server 系统升级后, 出现了ssh 超时现象:只要putty连续3分钟左右没有输入, 就自动断开, 然后必须重新登陆, 很麻烦.在网上查了很多资料, 发现原因有多种, 环境变量TMOUT引起,ClientAliveCountMax和ClientAliveInterval设置问题或者甚至是防火墙的设置问题. 所以可以这么尝试: 1, echo $TMOUT 如果显示空白,表示没有设置,等于使用默认值0,一般情况下应该是不超时.如果大于0,可以在如/etc/profile之类文件中设置它为0. Definition:TMOUT:Ifsettoavaluegreaterthanzero,thevalueisinterpretedasthenumberofsecondstowaitforinputafterissuingtheprimaryprompt.Bashterminatesafterwaitingforthatnumberofsecondsifinputdoesnotarrive. 2.ClientAliveInterval60 在/etc/ssh/sshd_config中增加ClientAliveInterval 60, ClientAliveInterval指定了服务器端向客户端请求消息的时间间隔, 默认是0, 不发送.而ClientAliveInterval 60表示每分钟发送一次, 然后客户端响应, 这样就保持长连接了.这里比较怪的地方是:不是客户端主动发起保持连接的请求(如FTerm, CTerm等),而是需要服务器先主动.另外,至于ClientAliveCountMax, 使用默认值3即可.ClientAliveCountMax表示服务器发出请求后客户端没有响应的次数达到一定值, 就自动断开. 正常情况下, 客户端不会不响应. ClientAliveCountMax Setsthenumberofclientalivemessages(seebelow)whichmaybe sentwithoutsshd(8)receivinganymessagesbackfromtheclient. Ifthisthresholdisreachedwhileclientalivemessagesare beingsent,sshdwilldisconnecttheclient,terminatingtheses- sion.Itisimportanttonotethattheuseofclientalivemes- sagesisverydifferentfromTCPKeepAlive(below).Theclient alivemessagesaresentthroughtheencryptedchannelandthere- forewillnotbespoofable.TheTCPkeepaliveoptionenabledby TCPKeepAliveisspoofable.Theclientalivemechanismisvalu- ablewhentheclientorserverdependonknowingwhenaconnec- tion has become inactive.The default value is 3. If ClientAliveInterval (see below) is setto15,andClientAliveCountMaxisleftatthedefault,unre- sponsiveSSHclientswillbedisconnectedafterapproximately45 seconds. This option applies to protocol version 2 only.ClientAliveInterval Setsatimeoutintervalinsecondsafterwhichifnodatahas beenreceivedfromtheclient,sshd(8)willsendamessage throughtheencryptedchanneltorequestaresponsefromthe client.Thedefaultis0,indicatingthatthesemessageswill notbesenttotheclient.Thisoptionappliestoprotocolver- sion 2 only.3. 启用putty keepaliveputty -> Connection -> Seconds between keepalives ( 0 to turn off ), 默认为0, 改为60. 4. 上述3个方法应该能解决大部分问题, 如果不行, 请 man sshd_config, 然后尝试更改其他设置吧. |