If you've got IPv6 connectivity on Gentoo Linux, you may want to set some applications to prefer IPv6 over IPv4 addresses. This way, if both IPv4 and IPv6 addresses are returned from the DNS server, the application will go with the latter.
- Add ipv6 to the default USE flags in /etc/make.conf. Otherwise the applications built by emerge, will not necessarily be IPv6 aware.
Edit /etc/wget/wgetrc file and uncomment the following setting:
#/etc/wget/wgetrcConsequently, /usr/bin/emerge which uses wget as download engine, will try to pull the traffic via IPv6 first if only the DNS server of your mirror returns an IPv6 address.
prefer-family = IPv6
Edit /etc/conf.d/rsyncd and add --ipv6 to the RSYNC_OPTS variable.