                                    DNS - Overview

        DNS is both simple and complex.

        Computers are good with numbers and like everything labeled as such.

        Humans not so much.

        So we need a translation layer between humans and computers.

                                                                                             5 / 23

                                    DNS - Overview

        DNS is both simple and complex.

        Computers are good with numbers and like everything labeled as such.

        Humans not so much.

        So we need a translation layer between humans and computers.

        Domain Name System (DNS)

                                                                                             6 / 23

                                   DNS - Structure

        DNS is a pretty good example of a system which haas gone though many iterations.

                                                                                             7 / 23

                                   DNS - Structure

        DNS is a pretty good example of a system which haas gone though many iterations.

        Long ago the "internet" was small enough ye could draw a map of all computers on a

        single sheet of paper.

        "Internet" because it was the pre-internet, ARPANET.

                                                                                             8 / 23

                                   DNS - Structure

        DNS is a pretty good example of a system which haas gone though many iterations.

        Long ago the "internet" was small enough ye could draw a map of all computers on a

        single sheet of paper.

        "Internet" because it was the pre-internet, ARPANET.

        It started with a single text file, now known as a hostfile (

        https://www.rfc-editor.org/rfc/rfc608)

                                                                                             9 / 23

                                   DNS - Structure

        DNS is a pretty good example of a system which haas gone though many iterations.

        Long ago the "internet" was small enough ye could draw a map of all computers on a

        single sheet of paper.

        "Internet" because it was the pre-internet, ARPANET.

        It started with a single text file, now known as a hostfile (

        https://www.rfc-editor.org/rfc/rfc608)

        To get added to this file you would have to ask Elizabeth "Jake" Feinler (

        https://en.wikipedia.org/wiki/Elizabeth_J._Feinler) to be added.

        (Her life is really interesting and apparently she is still alive)

                                                                                            10 / 23

                                   DNS - Structure

        DNS is a pretty good example of a system which haas gone though many iterations.

        Long ago the "internet" was small enough ye could draw a map of all computers on a

        single sheet of paper.

        "Internet" because it was the pre-internet, ARPANET.

        It started with a single text file, now known as a hostfile (

        https://www.rfc-editor.org/rfc/rfc608)

        To get added to this file you would have to ask Elizabeth "Jake" Feinler (

        https://en.wikipedia.org/wiki/Elizabeth_J._Feinler) to be added.

        (Her life is really interesting and apparently she is still alive)

        Having a single file like this dosent scale well, so over time the ability to

        delegate responsibility was implemented.

                                                                                            11 / 23

                                   DNS - Structure

        DNS is a pretty good example of a system which haas gone though many iterations.

        Long ago the "internet" was small enough ye could draw a map of all computers on a

        single sheet of paper.

        "Internet" because it was the pre-internet, ARPANET.

        It started with a single text file, now known as a hostfile (

        https://www.rfc-editor.org/rfc/rfc608)

        To get added to this file you would have to ask Elizabeth "Jake" Feinler (

        https://en.wikipedia.org/wiki/Elizabeth_J._Feinler) to be added.

        (Her life is really interesting and apparently she is still alive)

        Having a single file like this dosent scale well, so over time the ability to

        delegate responsibility was implemented.

        For Skynet.ie the process goes as follows:

                                                                                            12 / 23

                                   DNS - Structure

        DNS is a pretty good example of a system which haas gone though many iterations.

        Long ago the "internet" was small enough ye could draw a map of all computers on a

        single sheet of paper.

        "Internet" because it was the pre-internet, ARPANET.

        It started with a single text file, now known as a hostfile (

        https://www.rfc-editor.org/rfc/rfc608)

        To get added to this file you would have to ask Elizabeth "Jake" Feinler (

        https://en.wikipedia.org/wiki/Elizabeth_J._Feinler) to be added.

        (Her life is really interesting and apparently she is still alive)

        Having a single file like this dosent scale well, so over time the ability to

        delegate responsibility was implemented.

        For Skynet.ie the process goes as follows:

           •  ICANN are the top level controllers but they delegate to:

                                                                                            13 / 23

                                   DNS - Structure

        DNS is a pretty good example of a system which haas gone though many iterations.

        Long ago the "internet" was small enough ye could draw a map of all computers on a

        single sheet of paper.

        "Internet" because it was the pre-internet, ARPANET.

        It started with a single text file, now known as a hostfile (

        https://www.rfc-editor.org/rfc/rfc608)

        To get added to this file you would have to ask Elizabeth "Jake" Feinler (

        https://en.wikipedia.org/wiki/Elizabeth_J._Feinler) to be added.

        (Her life is really interesting and apparently she is still alive)

        Having a single file like this dosent scale well, so over time the ability to

        delegate responsibility was implemented.

        For Skynet.ie the process goes as follows:

           •  ICANN are the top level controllers but they delegate to:

              ◦  https://en.wikipedia.org/wiki/ICANN

                                                                                            14 / 23

                                   DNS - Structure

        DNS is a pretty good example of a system which haas gone though many iterations.

        Long ago the "internet" was small enough ye could draw a map of all computers on a

        single sheet of paper.

        "Internet" because it was the pre-internet, ARPANET.

        It started with a single text file, now known as a hostfile (

        https://www.rfc-editor.org/rfc/rfc608)

        To get added to this file you would have to ask Elizabeth "Jake" Feinler (

        https://en.wikipedia.org/wiki/Elizabeth_J._Feinler) to be added.

        (Her life is really interesting and apparently she is still alive)

        Having a single file like this dosent scale well, so over time the ability to

        delegate responsibility was implemented.

        For Skynet.ie the process goes as follows:

           •  ICANN are the top level controllers but they delegate to:

              ◦  https://en.wikipedia.org/wiki/ICANN

           •  IEDR, These folks are in charge of all .ie domains

                                                                                            15 / 23

                                   DNS - Structure

        DNS is a pretty good example of a system which haas gone though many iterations.

        Long ago the "internet" was small enough ye could draw a map of all computers on a

        single sheet of paper.

        "Internet" because it was the pre-internet, ARPANET.

        It started with a single text file, now known as a hostfile (

        https://www.rfc-editor.org/rfc/rfc608)

        To get added to this file you would have to ask Elizabeth "Jake" Feinler (

        https://en.wikipedia.org/wiki/Elizabeth_J._Feinler) to be added.

        (Her life is really interesting and apparently she is still alive)

        Having a single file like this dosent scale well, so over time the ability to

        delegate responsibility was implemented.

        For Skynet.ie the process goes as follows:

           •  ICANN are the top level controllers but they delegate to:

              ◦  https://en.wikipedia.org/wiki/ICANN

           •  IEDR, These folks are in charge of all .ie domains

              ◦  https://en.wikipedia.org/wiki/IE_Domain_Registry

                                                                                            16 / 23

                                   DNS - Structure

        DNS is a pretty good example of a system which haas gone though many iterations.

        Long ago the "internet" was small enough ye could draw a map of all computers on a

        single sheet of paper.

        "Internet" because it was the pre-internet, ARPANET.

        It started with a single text file, now known as a hostfile (

        https://www.rfc-editor.org/rfc/rfc608)

        To get added to this file you would have to ask Elizabeth "Jake" Feinler (

        https://en.wikipedia.org/wiki/Elizabeth_J._Feinler) to be added.

        (Her life is really interesting and apparently she is still alive)

        Having a single file like this dosent scale well, so over time the ability to

        delegate responsibility was implemented.

        For Skynet.ie the process goes as follows:

           •  ICANN are the top level controllers but they delegate to:

              ◦  https://en.wikipedia.org/wiki/ICANN

           •  IEDR, These folks are in charge of all .ie domains

              ◦  https://en.wikipedia.org/wiki/IE_Domain_Registry

           •  Skynet, we host our own DNS server                                            17 / 23

                                   DNS - Structure

        DNS is a pretty good example of a system which haas gone though many iterations.

        Long ago the "internet" was small enough ye could draw a map of all computers on a

        single sheet of paper.

        "Internet" because it was the pre-internet, ARPANET.

        It started with a single text file, now known as a hostfile (

        https://www.rfc-editor.org/rfc/rfc608)

        To get added to this file you would have to ask Elizabeth "Jake" Feinler (

        https://en.wikipedia.org/wiki/Elizabeth_J._Feinler) to be added.

        (Her life is really interesting and apparently she is still alive)

        Having a single file like this dosent scale well, so over time the ability to

        delegate responsibility was implemented.

        For Skynet.ie the process goes as follows:

           •  ICANN are the top level controllers but they delegate to:

              ◦  https://en.wikipedia.org/wiki/ICANN

           •  IEDR, These folks are in charge of all .ie domains

              ◦  https://en.wikipedia.org/wiki/IE_Domain_Registry

           •  Skynet, we host our own DNS server                                            18 / 23

                                   DNS - Structure

        DNS records are pretty simple.

        A single record per line in a consistent format

                                                                                            19 / 23

                                   DNS - Structure

        DNS records are pretty simple.

        A single record per line in a consistent format

        This defines where to find the skynet.skynet.ie server.

        Then it creates a subdomain *.users.skynet.skynet.ie which is a wildcard.

        So silver.users.skynet.skynet.ie matches.

                           # {NAME}  {TYPE}   {WHERE IT POINTS TO}

                           skynet  IN A     193.1.96.165

                           *.users IN CNAME skynet

                                                                                            20 / 23

                                   DNS - Structure

        DNS records are pretty simple.

        A single record per line in a consistent format

        This defines where to find the skynet.skynet.ie server.

        Then it creates a subdomain *.users.skynet.skynet.ie which is a wildcard.

        So silver.users.skynet.skynet.ie matches.

                           # {NAME}  {TYPE}   {WHERE IT POINTS TO}

                           skynet  IN A     193.1.96.165

                           *.users IN CNAME skynet

        You can use DNS to distribute other useful information, such as email config:

                        skynet.ie. IN TXT   "v=spf1 a:mail.skynet.ie -all"

                                                                                            21 / 23

                             DNS - Viewing records

        ▓▓▓ Live DNS

        We can use a command to get records for anything.

        Ye can also specify what server to get the request from.

                           dig skynet.ie

                           dig skynet.ie @1.1.1.1

                           dig skynet.ie @ns1.skynet.ie

                           host 193.1.99.75

                                                                                            22 / 23

                             DNS - Viewing records

        ▓▓▓ Live DNS

        We can use a command to get records for anything.

        Ye can also specify what server to get the request from.

                           dig skynet.ie

                           dig skynet.ie @1.1.1.1

                           dig skynet.ie @ns1.skynet.ie

                           host 193.1.99.75

        ▓▓▓ Nixos DNS

        Since we run our own dns server we can pull the actual file directly from nixos (

        https://forgejo.skynet.ie/Skynet/nixos):

                 colmena build --keep-result --on vendetta

                 cat .gcroots/node-vendetta/etc/skynet/dns/skynet.ie

cat

                 .gcroots/node-vendetta/etc/skynet/dns/64-64.99.1.193.in-addr.arpa

                                                                                            23 / 23