Firewall Analysis & Network Spotting
Uncomplicated Firewall Analysis
I set up an Ubuntu server with DigitalOcean that can be accessed with ssh. After installing UFW(Uncomplicated Firewall)inside the server, I discovered that there was a total of 9879 requests from the internet. Considering that I don't have any content in my server, that was a lot! I used `sudo cat /var/log/ufw.log` to log all the traces that were blocked by UFW.
I found some online resources about how to analyze the UFW log. According to the source, the ip address next to `src=`is where the packet came from. Although I didn't analyze all of the 9879 requests, I was able to track some of the logs with ipinfo.io. Here are some info of the IP addresses that tried to access my server:
- 217.21.193.74 : a search engine called Dataprovider in Amsterdam
- 74.120.14.17: A cloud service called Censys
- 47.106.154.1: An advertising company called Hangzhou Alibaba Advertising Co.,Ltd from Shenzen
I was surprised to find out that there were a lot of automated search engines or bots that are constantly accessing random servers, even though I just set up my server 2 days ago.
Network spotting
We live inside a computer
I was surprised to find out that ENIAC was intended as a personal computer that you lived inside. With several networks surrounding us and tech being the norm for every industry, it made sense that the whole society is living inside a computer.
Orange spray paints
After reading Networks of New York, I started spotting around manholes and orange paint near my neighborhood. I could find a trail of orange spray paints through Bergen St in Brooklyn. Judging from the T sign, this would be a traditional land-line telephone cable.
I also could notice some 'makeshift' signs near construction sites: For example, the photo below indicates there is an underground room beneath the construction site.
