Website down before a campaign: DNS or hosting first?

[NiceNICDomainServer]

When a landing page stops loading before or during a campaign, the cause is not always the hosting server.

It could be DNS, nameserver settings, DNS records, CDN/SSL, cache, or the web server itself.

For affiliate or campaign pages, what do you usually check first: domain/DNS setup, or hosting logs and monitoring?

 

[Graybeard]

1. Typo in the URL in the ad—is there a 404 error?
2. No response? Open the IP of the server in a browser or better

   $ curl  -I -Lv -H "User-Agent: Mozilla/5.0 "  "https://www.domain.com/"

   can you connect to the server (at all)?
3. Last check if there is a DNS issue

   $ dig NS domain.com

   Windows:
   

   nslookup -type=ns domain.com #(Standard Command Prompt)
   Resolve-DnsName -Name domain.com -Type NS #(PowerShell)

4. 

DNS after working is normally cached for hours or days on the DNS Server for that domain. DNS server FAILs are rare.