DNS (Doman Name Service)

DNS servers

Each site has its own local DNS server(s). There are a few reasons for this, one of which is subtle but important:

Have master zone files and be able to respond authoritatively for CSE DNS zones.
The important but subtle reason: all DNS queries regarding “unsw.edu.au” are redirected to UNSW's own internal DNS servers so that these queries appear to be coming from hosts inside UNSW.
This is so that the replies are relevant to hosts which should nominally be considered to be inside UNSW and which connect to UNSW services via internal UNSW networking rather than through the public Internet.
This is particularly the case, for example, with queries regarding the UNSW Active Directory (AD) servers (“ad.unsw.edu.au”) where if we queried via the public Internet we'd get the IP address of a non-informative public-facing server, but when we query internally to UNSW we would get a full list of AD servers addresses.
Provide forwarding of non-CSE and non-UNSW zone queries to the local AWS DNS server in each VPC.

Names (A) and alias (CNAME) records for public-facing roles. E.g., www, smtp, cgi, login
Roles are intended for use by people outside of CSE/UNSW

Internal names (A) and aliases (CNAME) records not intended for visibility outside of CSE. E.g., individual lab computer names, server names, network node names, etc.
For management by CSG

External-facing technical function names (not records pertaining to individual hosts)
Roles are intended for use by CSE staff, CSE students and other CSE users

Event-based names (A) and aliases (CNAME) records for promotion and marketing, probably exclusively referring to web pages or web sites. E.g.:
- Conference names (“ABCD2021” → https://abcd2021.cseunsw.online), or
- Possibly class and/or course names for class web pages (“COMP1234” → https://comp1234.cseunsw.online)