Network abnormally slow during night hours

Question

My network recently the last week as become abnormally slow around 11 pm. Very slow buffering youtube videos during all hours. Ive recently purchased the new router about two months ago but not until the other day has it become very slow. I have 1 port open to allow myself connection to a server but I believe i have a strong password. How do I go about figuring out what is wrong. I feel it is a security problem.
I use wpa for my wifi. Like I said i run a server so a port is open. Should i use traceroute? If so how?

Answer 1

1. Change the password of your AP
2. Read the logs of your IP to see who's authenticated at those periods in time
3. Check your servers logs (is it generating traffic maybe?)
4. use tshark/wireshark on your server to analyze, use graphing tools like munin and cacti to determine the amount of traffic
5. If all of the above don't work check with your ISP