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Old 06-10-2009, 10:27 PM   #1
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Registered: Sep 2008
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Question why port connect was failed sometimes from the internat?


recently I found a strange problem, sometimes the users from the internat can not connect to the mail server's ports( can ping and can trace route, but if telnet port will closed immediately ), but the internet users never meet such questions.

such status may continue several minutes or hours, usually in none-work time, and then restore normal without any actions.

the gateway's public ip:

the mailserver's public ip:

No iptables block/drop in the gateway and the mailserver.
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Last edited by alanshore; 06-10-2009 at 10:40 PM.
Old 06-11-2009, 04:19 AM   #2
Registered: Nov 2004
Location: Russia (St.Petersburg)
Distribution: Debian
Posts: 666

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check logs of your mailserver; if it will get nothing, try to monitor system/network activity for overloading; and if it's all right again, test if the mailserver receives queries indeed, using tcpdump or something, when the problem appears


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