DNS

https://slides.com/thewheat/dns

What is it?

  • Domain Name System (DNS)
  • The phonebook of the Internet
  • A lookup from human readable text to Internet Protocol (IP) addresses

Resource: https://www.cloudflare.com/learning/dns/what-is-dns/

Many kinds of DNS records

  • https://en.wikipedia.org/wiki/List_of_DNS_record_types
  • Most common / important ones
    • A: translates to IPv4 address (e.g. 192.0.2.1) 
    • AAAA: translates to an IPv6 address (e.g. 2001:0db8:85a3:0000:0000:8a2e:0370:7334)
    • CNAME: an alias for another domain (e.g. custom.intercom.help)
    • TXT: just text value used for things like authentication
    • MX: for setting up email servers (e.g. ASPMX.L.GOOGLE.COM)

Many kinds of DNS records

What makes up a DNS record?

  • Most common parts
    • ​Type
    • Host: which subdomain is it active on
    • Value: what is the value of the record
    • TTL: how long should it should be cached/valid for before asking for the latest value

Layers like an onion

Source: https://www.homenethowto.com/advanced-topics/traffic-example-the-full-picture/

Layers like an onion

Source: https://www.homenethowto.com/advanced-topics/traffic-example-the-full-picture/

Layers like an onion

Source: https://www.homenethowto.com/advanced-topics/traffic-example-the-full-picture/

Layers like an onion

Source: https://www.homenethowto.com/advanced-topics/traffic-example-the-full-picture/

Which DNS server?

  • Nameservers
  • Configured in domain registrar

How to tell which DNS server?

MXToolBox is a very very good friend

Other tools

  • dig

Other tools

Help Centers & HTTPS Custom Domain

  • Help Center is hosted on our servers
  • Our certificate is only valid for *.intercom.help domains

Help Centers & HTTPS Custom Domain

Help Centers & HTTPS Custom Domain

  • Regular CNAME investigations not fully valid for these cases 

Help Centers & HTTPS Custom Domain

  • Because in this system in the middle between the end user and actual website
  • It can handle all requests at the root domain level and have internal configurations to direct the subdomain to the appropriate location without needing a DNS record

Typical problems

  • Setting the wrong value
    • Using something like `theirdomain.intercom.help` or `intercomworkspacename.intercom.help` instead of `custom.intercom.help`
  • Setting up the wrong domain servers
  • Not following all instructions in our custom setup

Some examples

1. Why isn't `help.timothyandruth.com` working? See my settings below

2. I set up `docs3.thewheatfield.org`. Why isn't it working?

Set up your own custom help center

  1. Log into Namecheap via 1Password
  2. Create your own CNAME and set it up on your own help center

Let's try set up Cloudflare

What could possibly go wrong? 😂

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