Control excessive outbound traffic

Ubuntu server is sending outbound request excessively. I am not sure why this happening.

Following is the output I am getting for tcpdump

root@demotrt:~# tcpdump -n -n port 53
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Etheet), capture size 262144 bytes
04:41:30.345235 IP 45.33.119.111.56543 > 198.58.107.5.53: 56299+ A? jorgee3.pokemoninc.com.members.linode.com. (59)
04:41:30.345493 IP 198.58.107.5.53 > 45.33.119.111.56543: 56299 NXDomain* 0/0/0 (59)
04:41:30.345557 IP 45.33.119.111.46290 > 198.58.107.5.53: 56300+ A? jorgee3.pokemoninc.com. (40)
04:41:30.345813 IP 198.58.107.5.53 > 45.33.119.111.46290: 56300 NXDomain 0/1/0 (100)
04:41:30.345873 IP 45.33.119.111.48219 > 198.58.107.5.53: 56301+ A? jorgee3.pokemoninc.com.members.linode.com. (59)
04:41:30.346173 IP 198.58.107.5.53 > 45.33.119.111.48219: 56301 NXDomain* 0/0/0 (59)
04:41:30.346316 IP 45.33.119.111.54934 > 198.58.107.5.53: 56302+ A? jorgee3.pokemoninc.com. (40)
04:41:30.346546 IP 198.58.107.5.53 > 45.33.119.111.54934: 56302 NXDomain 0/1/0 (100)
04:41:30.346601 IP 45.33.119.111.52024 > 198.58.107.5.53: 56303+ A? jorgee3.pokemoninc.com.members.linode.com. (59)
04:41:30.346860 IP 198.58.107.5.53 > 45.33.119.111.52024: 56303 NXDomain* 0/0/0 (59)
04:41:30.346914 IP 45.33.119.111.58311 > 198.58.107.5.53: 56304+ A? jorgee3.pokemoninc.com. (40)
04:41:30.347158 IP 198.58.107.5.53 > 45.33.119.111.58311: 56304 NXDomain 0/1/0 (100)
04

I think something is not correct with the port 53.

Another uncommon think I have notice is, port is keep changing.

root@demotrt:~# netstat -apn|grep -w 53
udp        0      0 45.33.119.111:60095     198.58.107.5:53         ESTABLISHED -               
root@demotrt:~# netstat -apn|grep -w 53
udp        0      0 45.33.119.111:45498     198.58.107.5:53         ESTABLISHED -               
root@demotrt:~# netstat -apn|grep -w 53
udp        0      0 45.33.119.111:44618     198.58.107.5:53         ESTABLISHED -               
root@demotrt:~# netstat -apn|grep -w 53
udp        0      0 45.33.119.111:33521     198.58.107.5:53         ESTABLISHED -

How can I stop these requests? How can I control outbound excessive traffic?