https://github.com/anarchotechnyc/meta/wiki
https://www.arin.net/resources/registry/whois/rws/api/ # whois api for arin.net (US registrar)
OpenVisualTraceroute - GeoIP Databases (maxmind geoip)
traceroute -P icmp - trace over icmp instead of udp
/etc/services # list of default protocol mappings
nc # netcat - directly open tcp connections for explicit textual protocol
conversation nc -z to quickly scan for open port
nmap # network mapper - -Pn skip host enumeration to scan all ports for known to be online host
whois # to discover netrange for a speicifc customer, nmap can scan said netrange
censys.io # search for indexed ip addresses
shodan.io # search for IOT type devices, looks over internet for specific server headers