Hello, On a remote server (in an IPv6-only infrastructure) I am getting the following error when trying to update CentOS 8 Streams x86_64: $ sudo dnf upgrade --refresh Failed to set locale, defaulting to C.UTF-8 CentOS Stream 8 - AppStream 0.0 B/s | 0 B 00:16 Errors during downloading metadata for repository 'appstream': - Curl error (7): Couldn't connect to server for http://mirrorlist.centos.org/?release=8-stream&arch=x86_64&repo=AppStream&infra=stock [Failed to connect to mirrorlist.centos.org port 80: Permission denied] Error: Failed to download metadata for repo 'appstream': Cannot prepare internal mirrorlist: Curl error (7): Couldn't connect to server for http://mirrorlist.centos.org/?release=8-stream&arch=x86_64&repo=AppStream&infra=stock [Failed to connect to mirrorlist.centos.org port 80: Permission denied] Trying to retrieve the mirror list with wget gives similar errors (see log below). This is a development VM and I was playing with firewalld zones on this interface (drop, block, etc.) in order to see the most restrictive that I could use in order to update a system. But the error also appears if I switch back the zone to public. Could it be that my address has been blacklisted because of all these tests? >From my laptop, also running CentOS 8 Streams, everything is working as expected. Thank in advance for hints on how to analyze further! Mathieu ## wget log $ wget http://mirrorlist.centos.org/?release=8-stream&arch=x86_64&repo=AppStream&infra=stock --2021-02-19 08:35:14-- http://mirrorlist.centos.org/?release=8-stream&arch=x86_64&repo=AppStream&infra=stock Resolving mirrorlist.centos.org (mirrorlist.centos.org)... 2001:4178:5:200::10, 2600:1f16:c1:5e01:4180:6610:5482:c1c0, 2604:1380:2001:d00::3, ... Connecting to mirrorlist.centos.org (mirrorlist.centos.org)|2001:4178:5:200::10|:80... failed: Permission denied. Connecting to mirrorlist.centos.org (mirrorlist.centos.org)|2600:1f16:c1:5e01:4180:6610:5482:c1c0|:80... failed: Permission denied. Connecting to mirrorlist.centos.org (mirrorlist.centos.org)|2604:1380:2001:d00::3|:80... failed: Permission denied. Connecting to mirrorlist.centos.org (mirrorlist.centos.org)|2604:1580:fe02:2::10|:80... failed: Permission denied. Connecting to mirrorlist.centos.org (mirrorlist.centos.org)|2604:1380:1001:6c00::1|:80... failed: Permission denied. Connecting to mirrorlist.centos.org (mirrorlist.centos.org)|2a05:d012:8b5:6503:9efb:5cad:348f:e826|:80... failed: Permission denied.