Patrick Archibald wrote:
I did call my AS/400 domain.com. Why is that bad?
Short answer is "Because it's incorrect."
Longer answer starts with "How did you manage to do that?"
CFGTCP option 12 (Change TCP/IP domain information) should have a
host name and the appropriate domain name both specified. If your
domain name is "domain.com", then the appropriate host name should
be set in the 'Host name' field. Assume your host name is 'myas400'.
Now, in CFGTCP option 10 (Work with TCP/IP host table entries),
there should be an entry that has your system's main IP address with
a host name Name value of 'myas400.domain.com'. There may be up to
three "aliases" after the primary name for that IP address;
'myas400' could be a very reasonable alias.
One reason for all of this is that the gethostname() API then knows
what to return to programs that call it. It should return [a pointer
to the value] 'myas400.domain.com' in this case. The program can
then use that name to call the gethostbyname() API to find out what
IP address should be associated with that name.
The returned IP address should normally be an address that is
associated with an active interface in CFGTCP option 1 (Work with
So, when you have multiple interfaces with multiple addresses with
multiple names, there is a path through the configuration that ties
it all together.
Many things will work fine even when a configuration is incorrect.
But there's a definite chance that some component will someday need
a configuration value that was never requested before. When that
happens, the errors that result may be _very_ hard to track down.
("Our configuration hasn't changed in years. Why does _this_ program
One _possible_ example of an app that might expect a proper
configuration could be -- SMTP server or client.
IMO, it's better simply to have it set up properly at the start.