Вот что в логах заметил...

Jan 1 03:10:25 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:10:25 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:10:27 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:10:29 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:10:29 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:10:29 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:10:30 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:10:31 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:10:32 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:10:35 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:10:36 dropbear[293]: exit after auth (root): Exited normally
Jan 1 03:10:38 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:10:39 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:10:41 kernel: printk: 2 messages suppressed.
Jan 1 03:10:41 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:10:46 kernel: printk: 9 messages suppressed.
Jan 1 03:10:46 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:10:50 kernel: printk: 9 messages suppressed.
Jan 1 03:10:50 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:10:58 kernel: printk: 1 messages suppressed.
Jan 1 03:10:58 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:11:01 kernel: printk: 1 messages suppressed.
Jan 1 03:11:01 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:11:05 kernel: printk: 6 messages suppressed.
Jan 1 03:11:05 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:11:10 kernel: printk: 6 messages suppressed.
Jan 1 03:11:10 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:11:17 kernel: printk: 7 messages suppressed.
Jan 1 03:11:17 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:11:21 kernel: printk: 4 messages suppressed.
Jan 1 03:11:21 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:11:25 kernel: printk: 16 messages suppressed.
Jan 1 03:11:25 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:11:30 kernel: printk: 16 messages suppressed.
Jan 1 03:11:30 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:11:36 kernel: printk: 8 messages suppressed.
Jan 1 03:11:36 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:11:41 kernel: printk: 18 messages suppressed.
Jan 1 03:11:41 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:11:46 kernel: printk: 17 messages suppressed.
Jan 1 03:11:46 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:11:51 kernel: printk: 30 messages suppressed.
Jan 1 03:11:51 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:11:55 kernel: printk: 18 messages suppressed.
Jan 1 03:11:55 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:12:00 kernel: printk: 20 messages suppressed.
Jan 1 03:12:00 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:12:06 kernel: printk: 14 messages suppressed.
Jan 1 03:12:06 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:12:11 kernel: printk: 14 messages suppressed.
Jan 1 03:12:11 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:12:15 kernel: printk: 18 messages suppressed.
Jan 1 03:12:15 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:12:20 kernel: printk: 6 messages suppressed.
Jan 1 03:12:20 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:12:25 kernel: printk: 40 messages suppressed.
Jan 1 03:12:25 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:12:30 kernel: printk: 34 messages suppressed.
Jan 1 03:12:30 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:12:35 kernel: printk: 30 messages suppressed.
Jan 1 03:12:35 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:12:41 kernel: printk: 10 messages suppressed.
Jan 1 03:12:41 kernel: nf_conntrack: table full, dropping packet.
Jan 1 03:12:46 kernel: printk: 13 messages suppressed.
Jan 1 03:12:46 kernel: nf_conntrack: table full, dropping packet.