Redirected to cgi-sys/defaultwebpage.cgi, but only on some networks

Operating System & Version
Ubuntu 20.04
cPanel & WHM Version
106.0.9

idinc

Member
Nov 4, 2022
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I'm setting up a WHM/Cpanel server, using linode as my provider. I've gone through all the configuration steps to point my domain to my server, and configured a main domain account as well as a subdomain account in WHM, and put some test files for each.

What I'm finding is that on certain networks I can access both my domain and subdomain without issue, but on other networks the I am being redirected to the cgi-sys/defaultwebpage.cgi. I discovered this issue when configuring LetsEncrypt AutoSSL which kept getting 404s when trying to retrieve the challenge files using my domain name, I then tested with a machine on another network and discovered the redirect.

What might be going on here to cause this error on some networks but not others? Presumably the DNS records are working because I still am reaching the server, it just doesn't get routed to the correct virtual host.

So I'm not sure if this is a DNS zones issue or virtual host issue, I would really appreciate some help sorting this out! Can provide additional details on request. Thanks!

EDIT (SOLUTION): The problem was I accidentally configured AAAA ipv6 records without configuring ipv6, solution was to remove AAAA records
 
Last edited:

cPRex

Jurassic Moderator
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Oct 19, 2014
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Hey there! From one of the networks that isn't working, what happens when you try and ping the domain name, or do any other basic DNS checks? It sounds like the DNS may not be propagated to all locations, so checking this from one of the broken networks would be the best way to start narrowing things down.
 

idinc

Member
Nov 4, 2022
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Hi! Thanks for the quick reply.

When I ping from the networks that isn't working, the ping is successful. However it appears to be pinging an ipv6 address, vs when I ping from the network that works, it is pinging the ipv4.

I used the DNS manager on linode which created some AAAA entries by default, however I haven't configured any AAAA records in the WHM DNS zones. Perhaps this is part of the problem?

I will try two things while I wait for your response
  • Adding AAAA records to WHM DNS zones
  • Deleting all AAAA records including from linode DNS
Thanks!
 

idinc

Member
Nov 4, 2022
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This is definitely the issue. I just tried removing the AAAA records for my subdomain from the linode DNS, and I am now able to successfully access the subdomain.

So this was due to an incomplete ipv6 configuration. I'm going to now attempt to correctly configure the ipv6. Perhaps you could verify my checklist
  • Configure AAAA record for my FQDN configured in WHM in the linode DNS
  • Configure linode rDNS for ipv6 to the FQDN configured in WHM
  • Set ipv6 address in the "Basic Webhost Manager Setup"
  • Configure AAAA records for each domain in the linode DNS
  • Configure AAAA records for each domain in the WHM DNS zones
  • Rebuild httpd.conf
Anything else I may need to do configure to get ipv6 working?
 

cPRex

Jurassic Moderator
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Oct 19, 2014
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Is there a particular reason you need IPv6 addresses working? Most cPanel systems don't bother with IPv6 addresses at all. There are some additional details here:

 

idinc

Member
Nov 4, 2022
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No particular reason no. I'm new to configuring webservers and I thought maybe it was a recommended practice. If you're saying its not typically done I may just skip it. I will keep that link for reference should I change my mind. Thank you for your help!