In terms of SOA:
SOA: Start Of Authority
The SOA record is perhaps the least understood record in the entire zone file. But it controls the speed that any update is propagated throughout the Internet.
The purpose of the SOA record is:
Identify the DNS server that is authoritative for all information within the domain.
List the email address of the person in charge of the domain.
Control how often secondary servers check for changes to the zone file.
Control how long secondary servers keep the zone file active when the primary server cannot be contacted.
Control how long a negative response is cached by a DNS resolver (but for some DNS servers, this is also how long a DNS resolver should cache any response).
Now if you control all of the authoritative DNS servers for a domain (that is, the DNS servers that actually host the zone files and can answers queries for the domain as opposed to having to ask another DNS server), then with the exception of how long negative responses should be cached, these settings may not seem as important since you can force the secondary servers to update whenever needed.
You need to understand that in AAPANEL default settings such as:
$TTL 1D my.domain. IN SOA f1g1ns1.dnspod.net. admin.my.domain. (
0 ; serial
1D ; refresh
1H ; retry
1W ; expire
3H ) ; minimum
On the first line you are basically saying "Here, f1g1ns1.dnspod.net. is the master nameserver of the zone" which obviously is not true and should never be true. Someone in control of f1g1ns1.dnspod.net can do some nasty stuff with the zone's DNS.
And even if it can do harm, many tools that help diagnose DNS problems will fail due to the master zone being outside of AAPANEL operator's control.
From the SOA RFC
The fully-qualified domain name of the primary or master name server for the zone file. Within the structure of DNS, there can only be one server that holds the master, editable zone file. All secondary name servers create their zone files by transferring the contents from the primary name server. Changes to the domain's resource records are made to the primary name server's zone file and are then propagated to the secondary name servers when they check for updates.
So as a solution, when someone uses AAPANEL to host a DNS zone, please look at the attached image and set as the default SOA the value of NameServer 1.
As for the SERIAL of the Zone
One last comment, in the default config of a zone, the value of SERIAL does not increment. At least not in 6.6.7 and 6.6.8. It always stays at 0.
And please remember that a proper SERIAL zone format value is YYYMMSS where:
YYYY is the year
MM is the month
SS is a numerical sequence
It does not have to be like that, but a zone with a SERIAL of 43 has no meaning, while a zone with a SERIAL value of 20200343 means the year 2020, month march, version 43.
Perhaps you can read the numerical value of date and do value+1 when writing back to the file
Just my comments.
Cheers!
