Hello,
I have a following problem:
Current traffic too low… (under 1Mbps)
Ideas? 
Be a bit more precise about the observed traffic and link speed.
Make sure that you are not offering services to the WAN that you shouldn’t be. The DNS number looks high.
I fix a problem:
[admin@home] > ip dns set allow-remote-requests=no
[admin@home] > tool profile
NAME CPU USAGE
ethernet all 0.5%
console all 0%
firewall all 0%
networking all 1%
winbox all 0%
logging all 0.5%
management all 1%
idle all 94%
unclassified all 3%
Info about a problem:
http://blog.cloudflare.com/deep-inside-a-dns-amplification-ddos-attack
If DNS is needed setup proper firewall rules to block unwanted traffic and DNS/ddos attacks