In case you decide to re-enable IPv6, here a list of addresses for all mirror servers currently on the repo list. Note that these are the ones resolved from the domain names, it might not necessarily be the ones that are doing the syncing (although highly likely in most cases I guess).
IPv6 mirrors
manjaro.lucassymons.net -> 2606:4700:20::ac43:4a3e
manjaro.lucassymons.net -> 2606:4700:20::681a:8e0
manjaro.lucassymons.net -> 2606:4700:20::681a:9e0
mirror.aarnet.edu.au -> 2001:388:30bc:cafe::beef
mirror.inode.at -> 2001:730:3e14:8000::228
mirror.easyname.at -> No V6 address
mirror.xeonbd.com -> No V6 address
mirror.datacenter.by -> 2a02:2208:1:3::12
ftp.belnet.be -> 2001:6a8:3c80::27
mirror.futureweb.be -> 2a05:2880:e:2::
manjaro.c3sl.ufpr.br -> 2801:82:80ff:8000::2
linorg.usp.br -> 2001:12d0:0:71::183:235
www.caco.ic.unicamp.br -> No V6 address
mirrors.netix.net -> 2a00:1728:20::2
manjaro.ipacct.com -> 2a01:9e40::183
manjaro.telecoms.bg -> No V6 address
mirror.csclub.uwaterloo.ca -> 2620:101:f000:4901:c5c:0:f:1055
osmirror.org -> No V6 address
manjaro.dcc.uchile.cl -> No V6 address
mirror.ufro.cl -> No V6 address
mirror1.cl.netactuate.com -> 2607:f740:56:100:baca:3aff:fe6d:228
mirrors.huaweicloud.com -> No V6 address
mirrors.aliyun.com -> No V6 address
mirrors.ustc.edu.cn -> 2001:da8:d800:95::110
mirrors.tuna.tsinghua.edu.cn -> 2402:f000:1:408:8100::1
mirrors.tuna.tsinghua.edu.cn -> 2402:f000:1:408:8100::1
mirrors.sjtug.sjtu.edu.cn -> No V6 address
mirrors.ucr.ac.cr -> No V6 address
mirror.dkm.cz -> 2a02:8300:8000:3::49
mirrors.dotsrc.org -> 2001:878:346::116
www.uex.dk -> No V6 address
mirror.oldsql.cc -> 2001:41d0:a:25b3::1
manjaro.mcofficer.me -> No V6 address
manjaro.ynh.ovh -> No V6 address
ftp.free.org -> 2a01:e0d:1:8:58bf:fa83:0:1
kibo.remi.lu -> No V6 address
meauzoone.fr -> No V6 address
manjaro.grena.ge -> No V6 address
mirror.alpix.eu -> 2a01:4f8:150:3055::2
manjaro.re -> No V6 address
mirror.atysleaks.org -> 2a03:4000:4e:caf:543d:50ff:fef9:9dca
mirror.23media.com -> 2a00:f48:1007:32::30
ftp.halifax.rwth-aachen.de -> 2a00:8a60:e012:a00::21
ftp.tu-chemnitz.de -> 2001:638:911:b0e:134:109:228:1
mirror.netzspielplatz.de -> No V6 address
mirror.netcologne.de -> 2001:4dd0:1234:1::deb
manjaro.moson.eu -> 2a03:4000:47:4db:d492:aaff:fed2:7b39
manjaro.moson.org -> 2a03:4000:31:587:98a3:4dff:fe66:6c02
ftp.cc.uoc.gr -> 2001:648:2c00:6c05::2
ftp.cuhk.edu.hk -> 2405:3000:3:4::e
quantum-mirror.hu -> No V6 address
mirrors.opensource.is -> 2a06:a101:80:80::2
mirrors.piconets.webwerks.in -> 2401:7500:fff5:1::50
mirror.deace.id -> 2606:4700:3033::ac43:aff7
mirror.deace.id -> 2606:4700:3030::6815:3811
kartolo.sby.datautama.net.id -> 2403:ba00:602::1e
repo.iut.ac.ir -> No V6 address
manjaro.mirror.garr.it -> 2001:760:ffff:b6:4:100:0:70
manjaro.mirror.garr.it -> 2001:760:ffff:b6:4:100:0:72
manjaro.mirror.garr.it -> 2001:760:ffff:b6:4:100:0:73
ba.mirror.garr.it -> 2001:760:ffff:b6:4:100:0:69
ct.mirror.garr.it -> 2001:760:ffff:b6:4:100:0:69
ftp.riken.jp -> No V6 address
ftp.tsukuba.wide.ad.jp -> 2001:200:0:7c06::9393
manjaro.mirror.liquidtelecom.com -> 2c0f:fe40:8001:10::1
mirror.easylee.nl -> 2a00:1768:1001:82:303:606:808:909
manjaro.mirrors.lavatech.top -> No V6 address
ftp.nluug.nl -> 2001:67c:6ec:221:145:220:21:40
ftp.snt.utwente.nl -> 2001:67c:2564:a120::20
mirror.koddos.net -> 2001:590:3803::31:151
manjaro.mirrors.theom.nz -> No V6 address
mirror.terrahost.no -> 2a03:94e0:1803::1
repo.inara.pk -> No V6 address
mirror.rise.ph -> No V6 address
mirror.tuchola-dc.pl -> 2001:67c:2ad8::241
ftp.vectranet.pl -> 2a00:9f00:0:3::90
ftp.dei.uc.pt -> No V6 address
mirror.yandex.ru -> 2a02:6b8::183
mirror.truenetwork.ru -> No V6 address
download.nus.edu.sg -> No V6 address
mirror.is.co.za -> No V6 address
manjaro.mirror.ac.za -> 2001:4200:fffc::101
mirror.d-tl.com -> No V6 address
mirror.krmir.org -> 2606:4700:3034::ac43:91c0
mirror.krmir.org -> 2606:4700:3032::6815:4f89
ftp.caliu.cat -> No V6 address
ftp.lysator.liu.se -> 2001:6b0:17:f0a0::fd
mirror.zetup.net -> 2a02:1380:2009:1::4
manjaro.osmir.ch -> No V6 address
mirror.init7.net -> 2001:1620::1620
free.nchc.org.tw -> 2001:e10:2000:240:e643:4bff:fee8:a63c
mirror.kku.ac.th -> 2001:3c8:c108:2895::2
ftp.linux.org.tr -> No V6 address
mirrors.colocall.net -> No V6 address
fastmirror.pp.ua -> 2a01:d0:fa02:5555:6829:17ff:fe25:da0c
www.mirrorservice.org -> 2001:630:341:12::184
manjaro.mirrors.uk2.net -> No V6 address
uk.mirrors.fossho.st -> No V6 address
repo.ialab.dsu.edu -> No V6 address
distro.ibiblio.org -> No V6 address
mirrors.ocf.berkeley.edu -> 2607:f140:8801::1:30
mirror.math.princeton.edu -> No V6 address
mirror.clarkson.edu -> 2605:6480:c051:100::1
mirror.dacentec.com -> 2607:5600::c7bf:385a
mirrors.gigenet.com -> 2001:1850:f000:f000:f000:f000::
us.mirrors.fossho.st -> No V6 address
And in case you use ufw for fire-walling here a list with rules:
(in case the server has multiple network interfaces, you might want to change the “any”…)
ufw rules v6 mirrors
ufw allow from 2606:4700:20::ac43:4a3e to any port 873 comment "rsync: manjaro.lucassymons.net"
ufw allow from 2606:4700:20::681a:9e0 to any port 873 comment "rsync: manjaro.lucassymons.net"
ufw allow from 2606:4700:20::681a:8e0 to any port 873 comment "rsync: manjaro.lucassymons.net"
ufw allow from 2001:388:30bc:cafe::beef to any port 873 comment "rsync: mirror.aarnet.edu.au"
ufw allow from 2001:730:3e14:8000::228 to any port 873 comment "rsync: mirror.inode.at"
ufw allow from 2a02:2208:1:3::12 to any port 873 comment "rsync: mirror.datacenter.by"
ufw allow from 2001:6a8:3c80::27 to any port 873 comment "rsync: ftp.belnet.be"
ufw allow from 2a05:2880:e:2:: to any port 873 comment "rsync: mirror.futureweb.be"
ufw allow from 2801:82:80ff:8000::2 to any port 873 comment "rsync: manjaro.c3sl.ufpr.br"
ufw allow from 2001:12d0:0:71::183:235 to any port 873 comment "rsync: linorg.usp.br"
ufw allow from 2a00:1728:20::2 to any port 873 comment "rsync: mirrors.netix.net"
ufw allow from 2a01:9e40::183 to any port 873 comment "rsync: manjaro.ipacct.com"
ufw allow from 2620:101:f000:4901:c5c:0:f:1055 to any port 873 comment "rsync: mirror.csclub.uwaterloo.ca"
ufw allow from 2607:f740:56:100:baca:3aff:fe6d:228 to any port 873 comment "rsync: mirror1.cl.netactuate.com"
ufw allow from 2001:da8:d800:95::110 to any port 873 comment "rsync: mirrors.ustc.edu.cn"
ufw allow from 2402:f000:1:408:8100::1 to any port 873 comment "rsync: mirrors.tuna.tsinghua.edu.cn"
ufw allow from 2402:f000:1:408:8100::1 to any port 873 comment "rsync: mirrors.tuna.tsinghua.edu.cn"
ufw allow from 2a02:8300:8000:3::49 to any port 873 comment "rsync: mirror.dkm.cz"
ufw allow from 2001:878:346::116 to any port 873 comment "rsync: mirrors.dotsrc.org"
ufw allow from 2001:41d0:a:25b3::1 to any port 873 comment "rsync: mirror.oldsql.cc"
ufw allow from 2a01:e0d:1:8:58bf:fa83:0:1 to any port 873 comment "rsync: ftp.free.org"
ufw allow from 2a01:4f8:150:3055::2 to any port 873 comment "rsync: mirror.alpix.eu"
ufw allow from 2a03:4000:4e:caf:543d:50ff:fef9:9dca to any port 873 comment "rsync: mirror.atysleaks.org"
ufw allow from 2a00:f48:1007:32::30 to any port 873 comment "rsync: mirror.23media.com"
ufw allow from 2a00:8a60:e012:a00::21 to any port 873 comment "rsync: ftp.halifax.rwth-aachen.de"
ufw allow from 2001:638:911:b0e:134:109:228:1 to any port 873 comment "rsync: ftp.tu-chemnitz.de"
ufw allow from 2001:4dd0:1234:1::deb to any port 873 comment "rsync: mirror.netcologne.de"
ufw allow from 2a03:4000:47:4db:d492:aaff:fed2:7b39 to any port 873 comment "rsync: manjaro.moson.eu"
ufw allow from 2a03:4000:31:587:98a3:4dff:fe66:6c02 to any port 873 comment "rsync: manjaro.moson.org"
ufw allow from 2001:648:2c00:6c05::2 to any port 873 comment "rsync: ftp.cc.uoc.gr"
ufw allow from 2405:3000:3:4::e to any port 873 comment "rsync: ftp.cuhk.edu.hk"
ufw allow from 2a06:a101:80:80::2 to any port 873 comment "rsync: mirrors.opensource.is"
ufw allow from 2401:7500:fff5:1::50 to any port 873 comment "rsync: mirrors.piconets.webwerks.in"
ufw allow from 2606:4700:3030::6815:3811 to any port 873 comment "rsync: mirror.deace.id"
ufw allow from 2606:4700:3033::ac43:aff7 to any port 873 comment "rsync: mirror.deace.id"
ufw allow from 2403:ba00:602::1e to any port 873 comment "rsync: kartolo.sby.datautama.net.id"
ufw allow from 2001:760:ffff:b6:4:100:0:73 to any port 873 comment "rsync: manjaro.mirror.garr.it"
ufw allow from 2001:760:ffff:b6:4:100:0:70 to any port 873 comment "rsync: manjaro.mirror.garr.it"
ufw allow from 2001:760:ffff:b6:4:100:0:72 to any port 873 comment "rsync: manjaro.mirror.garr.it"
ufw allow from 2001:760:ffff:b6:4:100:0:69 to any port 873 comment "rsync: ba.mirror.garr.it"
ufw allow from 2001:760:ffff:b6:4:100:0:69 to any port 873 comment "rsync: ct.mirror.garr.it"
ufw allow from 2001:200:0:7c06::9393 to any port 873 comment "rsync: ftp.tsukuba.wide.ad.jp"
ufw allow from 2c0f:fe40:8001:10::1 to any port 873 comment "rsync: manjaro.mirror.liquidtelecom.com"
ufw allow from 2a00:1768:1001:82:303:606:808:909 to any port 873 comment "rsync: mirror.easylee.nl"
ufw allow from 2001:67c:6ec:221:145:220:21:40 to any port 873 comment "rsync: ftp.nluug.nl"
ufw allow from 2001:67c:2564:a120::20 to any port 873 comment "rsync: ftp.snt.utwente.nl"
ufw allow from 2001:590:3803::31:151 to any port 873 comment "rsync: mirror.koddos.net"
ufw allow from 2a03:94e0:1803::1 to any port 873 comment "rsync: mirror.terrahost.no"
ufw allow from 2001:67c:2ad8::241 to any port 873 comment "rsync: mirror.tuchola-dc.pl"
ufw allow from 2a00:9f00:0:3::90 to any port 873 comment "rsync: ftp.vectranet.pl"
ufw allow from 2a02:6b8::183 to any port 873 comment "rsync: mirror.yandex.ru"
ufw allow from 2001:4200:fffc::101 to any port 873 comment "rsync: manjaro.mirror.ac.za"
ufw allow from 2606:4700:3034::ac43:91c0 to any port 873 comment "rsync: mirror.krmir.org"
ufw allow from 2606:4700:3032::6815:4f89 to any port 873 comment "rsync: mirror.krmir.org"
ufw allow from 2001:6b0:17:f0a0::fd to any port 873 comment "rsync: ftp.lysator.liu.se"
ufw allow from 2a02:1380:2009:1::4 to any port 873 comment "rsync: mirror.zetup.net"
ufw allow from 2001:1620::1620 to any port 873 comment "rsync: mirror.init7.net"
ufw allow from 2001:e10:2000:240:e643:4bff:fee8:a63c to any port 873 comment "rsync: free.nchc.org.tw"
ufw allow from 2001:3c8:c108:2895::2 to any port 873 comment "rsync: mirror.kku.ac.th"
ufw allow from 2a01:d0:fa02:5555:6829:17ff:fe25:da0c to any port 873 comment "rsync: fastmirror.pp.ua"
ufw allow from 2001:630:341:12::184 to any port 873 comment "rsync: www.mirrorservice.org"
ufw allow from 2607:f140:8801::1:30 to any port 873 comment "rsync: mirrors.ocf.berkeley.edu"
ufw allow from 2605:6480:c051:100::1 to any port 873 comment "rsync: mirror.clarkson.edu"
ufw allow from 2607:5600::c7bf:385a to any port 873 comment "rsync: mirror.dacentec.com"
ufw allow from 2001:1850:f000:f000:f000:f000:: to any port 873 comment "rsync: mirrors.gigenet.com"