CNAME and IPv6

[Peter]

On Tue, May 28, 2024 at 12:25:03PM +0200, Marco Moock wrote:
! Am 28.05.2024 um 12:00:09 Uhr schrieb Peter:
! 
! >   if I understand corrently, the use of CNAME is just a convenience
! > and no technical feature, right?
! 
! It is technical because the query is redirected to the domain listed in
! the CNAME.

Seen that way, yes. Not using CNAME would then even be a load reducing
improvement.

! > Often, the webserver and other applications are not actually
! > running on node 1.2.3.4, but are internally portforwarded to
! > some other node, for various reasons.
! 
! This is bad IPv4 stuff, you should get rid off that ASAP.

Yes, that's the official stance...

! > Now we add an IPv6 address for 'myhost'. But portforwarding
! > doesn't work for IPv6. Instead we are required to use different
! > addresses all over, like so:
! 
! port forwarding would work, but is nasty here. Redirectors like rinetd
! can handle that, but I recommend against in this case.

I tried it, and didn't get around the Path MTU discovery: Forward SNMP
to one host, HTTP to another - which one then gets the ICMPv6 2.0
"message too big"? 

! > So, how would you do it? Is there a nice and elegant way?
! 
! www	CNAME	webserver1
! ftp	CNAME	ftp2
! 
! webserver1	A	192.168.0.1
! webserver1	AAAA	2001:db8::1
! ftp2		A	172.16.0.1
! ftp2		AAAA	2001:db8:9999::1
! 
! That makes it possible to redirect it to the actual machines that runs
! the service.

Okay, looks good. Lets go that way.

Thanks for Your reply!
PMc