NAT Port Forward from WAN to ::1 not working

[itn3rd77]

Hi,

I am asking for help in a case I could swear it worked in the past.

Some days ago I received a mail fom Let's Encrypt about my certificates are about to expire and looked in the ACME Client logs and yeap all attempts to renew where failed.

I briefly describe what was working in the past:

- NAT Port Forward on WAN to ::1 port 80
- HAProxy listening on [::1]:80 and forward ACME HTTP-01 challange requests to [::1]:43580

The redirect is working according to Firewall Live View (see screenshot) but even a tcpdump (/usr/sbin/tcpdump -i lo0 -vv -n port 80) on the loopback device shows no traffic for port 80 and therefore nothing in the logs of HAproxy. I don't see anything blocked and redirects on LAN interface to ::1 are working 

As I urgently needed to renew my Let's Encrypt certificates I just added a the VIP fd00:61:63:6d::65 to my LAN interface and changed the NAT Port Forward on WAN to fd00:61:63:6d::65 port 80 and changed the listen address for HAproxy. That worked but no way to get redirect on WAN working again with ::1.

I really don't get into it. Am I missing something?

Thanks and best regards
Ingo