external.servercentral.com has no SRV records.
Question and response
Question
dig external.servercentral.com. SRV
Answer
The response has no answer records.
Authority
servercentral.com. 600 SOA ns1.servercentral.net. dns.servercentral.net. 2025110302 600 600 600 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0