Nothing has been modified on any of the numerous boxes I have. It all happened since I upgraded to Core160 as well as the current MiniPC with Core160 upgraded to Core163.
They are all on the same Gigabit switch getting DHCP addresses from the IPFire box.
The raspios and Ubuntu PC and SBC’s all show the same problem, the openSUSE boxes all cannot resolve ardiono.cc.
openSUSE Tumbleweed x86_64
slipstream:~ # dig www.arduino.cc
; <<>> DiG 9.16.25 <<>> www.arduino.cc
;; global options: +cmd
;; connection timed out; no servers could be reached
slipstream:~ #
However, no problem with the Fedora 35 x86_64 box.
[root@Fedora ~]# dig www.arduino.cc
; <<>> DiG 9.16.24-RH <<>> www.arduino.cc
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 26255
;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 65494
;; QUESTION SECTION:
;www.arduino.cc. IN A
;; ANSWER SECTION:
www.arduino.cc. 170 IN CNAME www.arduino.cc.cdn.cloudflare.net.
www.arduino.cc.cdn.cloudflare.net. 170 IN A 104.18.28.45
www.arduino.cc.cdn.cloudflare.net. 170 IN A 104.18.29.45
;; Query time: 2 msec
;; SERVER: 127.0.0.53#53(127.0.0.53)
;; WHEN: Mon Feb 21 17:28:53 GMT 2022
;; MSG SIZE rcvd: 122
[root@Fedora ~]#
slipstream:~ # ip r
default via 192.168.10.103 dev enp3s0 proto dhcp metric 100
default via 192.168.0.1 dev wlp9s0f3u4u1 proto dhcp metric 600
172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1 linkdown
192.168.0.0/24 dev wlp9s0f3u4u1 proto kernel scope link src 192.168.0.11 metric 600
192.168.10.0/24 dev enp3s0 proto kernel scope link src 192.168.10.224 metric 100
192.168.100.0/24 dev virbr1 proto kernel scope link src 192.168.100.1 linkdown
192.168.122.0/24 dev virbr0 proto kernel scope link src 192.168.122.1 linkdown
slipstream:~ #
[root@Fedora ~]# ip r
default via 192.168.10.103 dev eno1 proto dhcp metric 100
default via 192.168.0.1 dev wlp2s0 proto dhcp metric 600
192.168.0.0/24 dev wlp2s0 proto kernel scope link src 192.168.0.13 metric 600
192.168.10.0/24 dev eno1 proto kernel scope link src 192.168.10.220 metric 100
192.168.122.0/24 dev virbr0 proto kernel scope link src 192.168.122.1 linkdown
[root@Fedora ~]#