4.9 doesn't answer on the tcp ports

[Zsolt Bognar]

Hello,

I have one FreeBSD 4.9-STABLE server, that recently started to behave
strangely. It is respones all ping request and I can change between consoles
and the ftp and mysql server response (but I can't login).
In the last week, it happened three-times.

So, the apache, sshd, etc. doesn't answer. I can't login to the sshd server.
And The CTRL+ALT+DEL also doesn't work.
There is not kernel panic and I couldn't see anything in the log files, only
the reset button helps.

Anyone met this problem?