In order to conserve the limited bandwidth available, ISO images are not downloadable from mirror.centos.org

http://repos-va.psychz.net/centos/8.1.1911/isos/aarch64/
http://mirror.centos.iad1.serverforge.org/8.1.1911/isos/aarch64/
http://repo1.ash.innoscale.net/centos/8.1.1911/isos/aarch64/
http://centos4.zswap.net/8.1.1911/isos/aarch64/
http://mirrors.advancedhosters.com/centos/8.1.1911/isos/aarch64/
http://mirror.vtti.vt.edu/centos/8.1.1911/isos/aarch64/
http://mirror.cogentco.com/pub/linux/centos/8.1.1911/isos/aarch64/
http://mirror.ash.fastserv.com/centos/8.1.1911/isos/aarch64/
http://mirror.cs.vt.edu/pub/CentOS/8.1.1911/isos/aarch64/
http://mirror.vcu.edu/pub/gnu_linux/centos/8.1.1911/isos/aarch64/
http://us.mirror.nsec.pt/centos/8.1.1911/isos/aarch64/

http://mirror.clarkson.edu/centos/8.1.1911/isos/aarch64/
http://mirror.pit.teraswitch.com/centos/8.1.1911/isos/aarch64/
http://yum.tamu.edu/centos/8.1.1911/isos/aarch64/
http://www.gtlib.gatech.edu/pub/centos/8.1.1911/isos/aarch64/
http://mirrors.tripadvisor.com/centos/8.1.1911/isos/aarch64/
http://mirror.web-ster.com/centos/8.1.1911/isos/aarch64/
http://mirrors.umflint.edu/CentOS/8.1.1911/isos/aarch64/
http://mirrors.codec-cluster.org/centos/8.1.1911/isos/aarch64/
http://mirror.ancl.hawaii.edu/linux/centos/8.1.1911/isos/aarch64/
http://mirror.chpc.utah.edu/pub/centos/8.1.1911/isos/aarch64/
http://repo1.sea.innoscale.net/centos/8.1.1911/isos/aarch64/
http://mirror.team-cymru.com/CentOS/8.1.1911/isos/aarch64/
http://mirror.dal.nexril.net/centos/8.1.1911/isos/aarch64/
http://mirror.metrocast.net/centos/8.1.1911/isos/aarch64/
http://mirror.phx1.us.spryservers.net/centos/8.1.1911/isos/aarch64/
http://repo1.dal.innoscale.net/centos/8.1.1911/isos/aarch64/
http://mirrors.unifiedlayer.com/centos/8.1.1911/isos/aarch64/
http://mirror.grid.uchicago.edu/pub/linux/centos/8.1.1911/isos/aarch64/
http://mirrors.liquidweb.com/CentOS/8.1.1911/isos/aarch64/
+ others, see the full list of mirrors: https://www.centos.org/download/mirrors/

Mirrors verified Fri May 29 18:14:59 2020 UTC

You can also download the ISO images using bittorrent, a peer-to-peer file sharing protocol. The .torrent files can be found from CentOS mirrors. Various bittorrent clients are available, including (in no particular order of preference): utorrent, vuze (Azureus), BitTorrent, Deluge, ctorrent, ktorrent, rtorrent and transmission. Packaged copies of various torrent clients for CentOS can be found in the repositories listed in the following wiki article: https://wiki.centos.org/AdditionalResources/Repositories