ECS Service Console: "Validate Node hostname" "Check DNS Settings" Fail with Case Mismatch
Summary: ECS service-console check for "Validate Node hostname" or "Check DNS settings" fails due to case mismatch between domain name system (DNS) hostname.
Symptoms
The following error is logged for each node with a mismatch:
20220101 12:00:00.000: Validate Node hostname [ERROR] The hostname on node 169.254.1.1 is 'ecsnode01.dell.com' and the fqdn from the ini file is 'ECSNODE01.dell.com' - they do not match
20231108 09:31:22.270: | | FAIL [ERROR] 'Check DNS settings' failed: Could not find 'ECSNODE01.dell.com' in 'nslookup 10.0.0.1' output. Node: 169.254.1.1 10.0.0.1.dell.com = ecsnode1.dell.com. Authoritative answers can be found from:
Cause
Resolution
Validate that the Forward and Reverse Zone DNS matches the hostname exactly.
In this example the Forward and Reverse DNS only, differ by case-sensitive thereby generating an alert.
In this example, the hostname is "ecsnode01.dell.com:"
admin@ecsnode01:~> hostname -f
ecsnode01.dell.com
Check Forward DNS on the user's system using nslookup and the FQDN of the node:
admin@ecsnode01:~> nslookup ecsnode01.dell.com Server: 192.1xx.2xx.254 Address: 192.1xx.2xx.254#53 Non-authoritative answer: Name: ecsnode01.dell.com Address: 10.0.0.1
In this example, the Forward DNS lookup matches the hostname. Both are all lowercase.
Check Reverse DNS on the user's system using nslookup and the IP address of the node:
admin@ecsnode01:~> nslookup 10.0.0.1 1.0.0.10.in-addr.arpa name = ECSNODE01.dell.com.in-addr.arpa. Authoritative answers can be found from:
In this example, the Reverse DNS lookup returns uppercase letters for the hostname. The Reverse DNS Zone should be updated to lowercase to match the hostname on the system.
To resolve this issue, change the entries in the DNS server as the FQDN in ECS cannot be altered. This issue DNS should be updated so that it matches the hostname. Any mismatch between the hostname, the Forward DNS lookup, or the Reverse DNS lookup causes this error.
User Action:
Article 80094: ECS: Is changing of the external or public name (FQDN) or the public IP address of an ECS node supported
If detected as a part of a preupgrade check:
20231107 12:51:45.771: | Check DNS settings 20231107 12:51:46.248: | | FAIL [ERROR] 'Check DNS settings' failed: Could not find 'ECSNODE1.ch.net.intra' in 'nslookup 10.0.0.1' output. Node: 169.2xx.1.1 10.0.0.1.in-addr.arpa name = ecsnode1.ch.net.intra. Authoritative answers can be found from:
It may be a false alert due to the case-sensitive difference and if it is only different regarding case-sensitive, then that does not block an upgrade.
Run the following checks for the node to check if it is a case-sensitive difference:
admin@ECSNODE1:~> hostname ECSNODE1.ch.net.intra admin@ECSNODE1:~> hostname -f ECSNODE1.ch.net.intra admin@ECSNODE1:~> hostname -i 10.0.0.1 admin@ECSNODE1:~> nslookup ECSNODE1 Server: 192.1xx.2xx.254 Address: 192.1xx.2xx.254#53 Non-authoritative answer: Name: ECSNODE1.ch.net.intra Address: 10.0.0.1 admin@ECSNODE1:~> nslookup ecsnode1 Server: 192.1xx.2xx.254 Address: 192.1xx.2xx.254#53 Non-authoritative answer: Name: ecsnode1.ch.net.intra Address: 10.0.0.1 admin@ECSNODE1:~> nslookup 10.0.0.1 1.88.96.10.in-addr.arpa name = ecsnode1.ch.net.intra. Authoritative answers can be found from: admin@ECSNODE1:~>
If the only difference detected is the letter case, then it is a false alert in the preupgrade check.