diff --git a/content/notes/cosc-203.md b/content/notes/cosc-203.md
index 5ed380b72..3af4038b7 100644
--- a/content/notes/cosc-203.md
+++ b/content/notes/cosc-203.md
@@ -21,8 +21,10 @@ tags:
 - [cosc203-lab16](notes/cosc203-lab16.md)
 - [cosc203-lab17](notes/cosc203-lab17.md)
 - [cosc203-lab18](notes/cosc203-lab18.md)
+- 
 
 # Notes
+[dns](notes/dns.md)
 
 # Lectures
 - [01-basic-html](notes/01-basic-html.md)
diff --git a/content/notes/cosc203-lab20.md b/content/notes/cosc203-lab20.md
new file mode 100644
index 000000000..fa5645466
--- /dev/null
+++ b/content/notes/cosc203-lab20.md
@@ -0,0 +1,9 @@
+---
+title: "cosc203-lab20"
+aliases: 
+tags: 
+- cosc203
+- lab
+---
+
+1. 
diff --git a/content/notes/dns.md b/content/notes/dns.md
index 7f8d96e38..6200bc9b9 100644
--- a/content/notes/dns.md
+++ b/content/notes/dns.md
@@ -23,4 +23,12 @@ Types
 - NS
 	- name - domain (e.g., otago.ac.nz)
 	- value  - hostname of authoritave DNS server that knows how to get the IP address for hosts in the domain
-	- used to route DNS queries further along th
\ No newline at end of file
+	- used to route DNS queries further along the query chain
+- CNAME
+	- value - canonical hostname for the alias hostname Name
+	- can provide querying the cananical name for a hostname
+- MX
+	- value - canonical name of a mail server that has an alias hostname name
+	- allows the hostnames of mail servers to have simple aliases
+	- allows a company to have the same aliased name for its mail server and for one of its other servers (e.g., web server)
+	- 
\ No newline at end of file