Ubuntu server fresh install 3 weeks old.

After 2 weeks ssh stopped working.

When i reboot ssh is listening but has to restarted every time. then it work

No iptables and lucky i have shellinabox installed which works fine

netstat -tln
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 0.0.0.0:4200 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:50923 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:46502 0.0.0.0:* LISTEN
tcp6 0 0 :::111 :::* LISTEN
tcp6 0 0 :::59536 :::* LISTEN
tcp6 0 0 :::22 :::* LISTEN
tcp6 0 0 :::12865 :::* LISTEN
tcp6 0 0 :::45185 :::* LISTEN