All my bandwidth eaten up - report included

Question

I have my network bandwidth eaten up totally. Whenever I connect my network, without any application being opened it is always full.

I have prepared report of iftop, nethogs and network system monitor.

iftop and nethogs

My host IP is 192.168.1.203 and all the rest are not known though I have tried to pin 192.168.1.105, it doesn't reply.

If possible I would like to block the most disturbing IP which is 192.168.1.105 to block it. but don't know how.

Answer 1

Assuming your server (the machine from which samples screenshot are coming) is you network gateway, you can try with iptables with a command line like this:

sudo iptables -A FORWARD -s 192.168.1.105 -j REJECT
sudo iptables -A FORWARD -d 192.168.1.105 -j REJECT

This will block all traffic to and from 192.168.1.105. That will cause you no problem, if you don't have private networks that you need access to, meaning that you're just routing traffic to internet. You'll have the risk that the machine simply change the IP address, then you'll have to figure out the mac address, for that you can use arp command:

$ arp -n
Address                  HWtype  HWaddress           Flags Mask            Iface
192.168.1.101            ether   00:0f:b0:74:f1:f3   C                     eth0