Firewalls
- Wikipedia definition
- Cisco marketing
- Firewalls are often maintained by network admin consultants
- iptables
- UFW — Uncomplicated Firewall
Our recent Pi problem
- Network Time Protocol
- ntpdc -c peers
- NTP DOS amplification attack
- NTP templates from Team Cymru
- sudo ntpdc -n -c monlist uncacsci-pi2-a.cs.unca.edu
- timesyncd