DNS

Some Notes from Ben Eater

Everything begins with DNS root servers.

"The authoritative name servers that serve the DNS root zone, commonly known as the “root servers”, are a network of hundreds of servers in many countries around the world. They are configured in the DNS root zone as 13 named authorities, as follows."

List of Root Servers

https://www.iana.org/domains/root/servers | | | | |---|---|---| |a.root-servers.net|198.41.0.4, 2001:503:ba3e::2:30|Verisign, Inc.| |b.root-servers.net|170.247.170.2, 2801:1b8:10::b|University of Southern California,
Information Sciences Institute| |c.root-servers.net|192.33.4.12, 2001:500:2::c|Cogent Communications| |d.root-servers.net|199.7.91.13, 2001:500:2d::d|University of Maryland| |e.root-servers.net|192.203.230.10, 2001:500:a8::e|NASA (Ames Research Center)| |f.root-servers.net|192.5.5.241, 2001:500:2f::f|Internet Systems Consortium, Inc.| |g.root-servers.net|192.112.36.4, 2001:500:12::d0d|US Department of Defense (NIC)| |h.root-servers.net|198.97.190.53, 2001:500:1::53|US Army (Research Lab)| |i.root-servers.net|192.36.148.17, 2001:7fe::53|Netnod| |j.root-servers.net|192.58.128.30, 2001:503:c27::2:30|Verisign, Inc.| |k.root-servers.net|193.0.14.129, 2001:7fd::1|RIPE NCC| |l.root-servers.net|199.7.83.42, 2001:500:9f::42|ICANN| |m.root-servers.net|202.12.27.33, 2001:dc3::35|WIDE Project|

Resolving IP Over the Internet

Begin with DNS resolution: There are 12 canonical root servers that maintain child nameservers that will connect a client through intermediary steps to a location.

Several other third party services host their own DNS name servers

|Provider|Primary DNS|Secondary DNS| |---|---|---| |Google|8.8.8.8|8.8.4.4| |Control D|76.76.2.0|76.76.10.0| |Quad9|9.9.9.9|149.112.112.112| |OpenDNS Home|208.67.222.222|208.67.220.220| |Cloudflare|1.1.1.1|1.0.0.1| |CleanBrowsing|185.228.168.9|185.228.169.9| |Alternate DNS|76.76.19.19|76.223.122.150| |AdGuard DNS|94.140.14.14|94.140.15.15|

After DNS Resolution Once an IP address has been determined, your computer will go through a series of routing tables to get where it needs to go.