Node Red MQTT Nodes Not Resolving DNS CNAME Records?

General
1

I have a DNS CNAME record set to broker.dd.org, the actual DNS name is infrastructure.dd.org. When I try to use the CNAME record the Node Red MQTT nodes fail to connect.

image

Use of IP address works
Use of actual DNS name (FQDN) or short name works
Use of CNAME record fails, node on the left is using IP or DNS name (as the case may be) the node on the right is using CNAME record, i.e. DNS alias (using the term loosely).

Any one else see this behavior.

Oh, and use pinging of the CNAME works, resolving the CNAME works, I have absolutely no reason to believe DNS is not working correctly in this case.

# nslookup broker.dd.org
Server: 192.168.1.137
Address: 192.168.1.137#53

broker.dd.org canonical name = infrastructure-ethernet.dd.org.
Name: infrastructure-ethernet.dd.org

# nslookup 192.168.1.3
3.1.168.192.in-addr.arpa name = infrastructure-ethernet.dd.org.

Reverse lookup should resolve to the actual device name record, not the CNAME record by the way.

I don't recall this being an issue in the past, but I have been away from NR for a while, could something in 3.0.x have changed to impact this? I know this did not happen in 1.x or 2.x. Might be a JavaScript thing?

2

Is node red running in Docker, or is it a native install? Are your test commands being run on the node red server machine?
Try the ping node and see if that sees it.

3

Not in docker. Ping node works against CNAME record. That would be expected behavior of course. I imported an older flow, and it is working, with the CNAME record. But the current newer flow still fails to connect. I am going to recreate the MQTT node and/or the flow see what happens. Feels like just have a bad node?

4

Try restarting node-red and see if then works.

5

Will do, after to it later today.

6

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