- 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. Google.com needs to translate into an IP address
- 4. Nslookup à google.com à gives a list of IP addresses for google.com (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. xyz.cloudapp.net on Azure)
- iii. MX
- 1. Email clients locate the right domain for a mail server
- 2. nslookup
- 3. Set type=mx
- 4. Google.com
- 5. This shows the email servers at google.com
- 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. 8.8.8.8
- 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. Google.com
- c. Set type=soa
- d. Google.com
- 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
- i. A
- 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
- i. Single
- 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
- a. Characteristics
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