AWS Certified SysOps Administrator Part VIII: Route 53


  • 1. Configuring Route 53
    • a. Characteristics
      • i. Name comes from the default DNS port of UDP Port 53
      • ii. Built from the ground up
      • iii. Worldwide distributed DNS
      • iv. Database of name to IP address mappings
      • v. Uptime SLA of 100%
      • vi. Server health checks
    • b. Record Types
      • i. A
        • 1. ‘A record’
        • 2. Name that points to an IP Address
        • 3. needs to translate into an IP address
        • 4. Nslookup à à gives a list of IP addresses for (gave a list of 11 IP addresses)
      • ii. CNAME
        • 1. An alias that just points to another name
        • 2. This allows us to put our custom names on top of sub-domains generated by cloud providers (e.g. on Azure)
      • iii. MX
        • 1. Email clients locate the right domain for a mail server
        • 2. nslookup
        • 3. Set type=mx
        • 4.
        • 5. This shows the email servers at
      • iv. AAAA
        • 1. IPV6 address record
      • v. TXT
        • 1. General purpose entry in DNS
        • 2. Used to verify that you own the domain name
      • vi. PTR
        • 1. Pointer record (opposite of an A record)
        • 2. I have an IP address and I need the name
        • 3. Nslookup
          • a. Set type=ptr
          • b.
          • c. Returns the name for that ip address
      • vii. SRV
        • 1. Service locator
        • 2. Configuring your voip system for example
      • viii. SPF
        • 1. Used to avoid spoofing
        • 2. When you add this record, you are advertising that you will only send email from a certain IP address
        • 3. If the email came from a different ip address and it isn’t listed in your SPF record then the mail server will flag the email
      • ix. NS
        • 1. Anybody that wants to access your domain, they need to access your name server
      • x. SOA
        • 1. Primary name server that has all the configuration for your domain
        • 2. Nslookup
          • a. Set type=ns
          • b.
          • c. Set type=soa
          • d.
        • 3. Start of authority
          • a. Time to live (TTL)
          • b. Primary name server
          • c. Responsible mail address
          • d. Serial, refresh rate, retry window, expiration window
    • c. Routing Policy
      • i. Single
        • 1. A record and associate an IP address
        • 2. When you specify multiple IP address it will round robin to all of those IP addresses
        • 3. If one of those go down, then DNS will still route traffic to that IP address that went down
      • ii. Weighted
        • 1. Give a portion of traffic to a specific percentage of the traffic that should get routed to a particular IP address
        • 2. It can go over 100%, the numbers are relative to each other
      • iii. Latency
        • 1. Maintain a database of latencies between an ip address and different locations around the world
        • 2. Route users to the ip address with the lowest latency
      • iv. Failover
        • 1. Associated with a health check
      • v. Geolocation
        • 1. Configure the records so that you can isolate users to a geo-specific instance of an application
    • d. Setup
      • i. You can register new / transfer existing domain names on AWS
      • ii. Hosted Zone
        • 1. Creates SOA and name servers automatically
        • 2. You can import a zone file

One thought on “AWS Certified SysOps Administrator Part VIII: Route 53

  1. Pingback: AWS Certified SysOps Administrator Exam: Study Guide | Sky Cliffs

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s