Why the server started to score traffic?

All kind time of days, I experienced a strange situation. In General I have a home server. Keep it for a couple of sites and, in General, that everything is fine and went the 23rd day of uptime. But then I decided to check out your settings and asked the guys for me to dudoit. In General I have nginx, Cloudflare(Free), iptables I have depo I didn't touch him and know everything was cool. Launched an attack all right Claude Bloch but look a little squat start site I on the fly included in the cloud check for cookies. everything is fine. not the contractions, not what. Netstat monitors BUT I have literally 50 connections from 1 ip but under different networks. And I didn't pay attention well, I think maybe all the same guy wants to finish.(Although he told me he had stopped) but not the point. A few minutes later, I stupidly falls network.The problem I do not understand. The trick is that the indicator on the switch I see that my server makes a spooky return well, that is the upload server side. pull out his LAN cord all the rules the ' net is working again it's cool, insert the wire back to the Internet drops again and I see that the server terribly eats traffic. To go sorry to the server I could not( unnecessarily in school access couldn't get out over the Internet and directly why it is not working keyboard is not awake and monitor) the Proper question dear, why did this happen? What that was all about? Tipo server screened queries or how to understand this correctly. And if anything I would be very grateful for a hint how to solve this and avoid this next time.

PS it's a pity uptime =( though he was a little well feel awful about.
July 9th 19 at 13:13
2 answers
July 9th 19 at 13:15
Start with learning the atop
July 9th 19 at 13:17
Not the uptime of unified... 8)
The network setting process has not changed on the server?
And rootkits not checked well used.

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