我去安装一个新程序，当我完成更新时，我收到了几个警告：
W：无法获取http://deb.debian.org/debian/dists/bullseye-updates/InRelease无法开始连接到 debian.map.fastlydns.net:80 (2a04:4e42:4::644) 。- 连接（101：网络无法访问）无法连接到 debian.map.fastlydns.net:80 (151.101.18.132)，连接超时无法开始连接到 deb.debian.org:80 (2a04:4e42:4: :644)。- 连接（101：网络不可访问）
W：无法获取http://deb.debian.org/debian/dists/bullseye/InRelease无法开始连接到 deb.debian.org:80 (2a04:4e42:4::644)。- 连接（101：网络不可访问）
W：某些索引文件无法下载、被跳过或使用旧的。
In the /etc/apt/sources.list file I have the following:
```lang-sh
# deb cdrom:[Debian GNU/Linux 11.2.0 _Bullseye_ - Official amd64 DVD Binary-1 20211218-11:13]/ bullseye contrib main
# deb cdrom:[Debian GNU/Linux 11.2.0 _Bullseye_ - Official amd64 DVD Binary-1 20211218-11:13]/ bullseye contrib main
deb http://security.debian.org/debian-security bullseye-security contrib non-free
deb-src http://security.debian.org/debian-security bullseye-security contrib non-free
# bullseye-updates, to get updates before a point release is made;
# see https://www.debian.org/doc/manuals/debian-reference/ch02.en.html#_updates_and_backports
# A network mirror was not selected during install. The following entries
# are provided as examples, but you should amend them as appropriate
# for your mirror of choice.
deb http://deb.debian.org/debian/ bullseye-updates main contrib
deb-src http://deb.debian.org/debian/ bullseye-updates main contrib
deb http://deb.debian.org/debian/ bullseye main contrib non-free
deb-src http://deb.debian.org/debian/ bullseye main contrib non-free
deb http://ftp.de.debian.org/debian sid main
deb https://fasttrack.debian.net/debian-fasttrack/ bullseye-fasttrack main contrib
deb https://fasttrack.debian.net/debian-fasttrack/ bullseye-backports-staging main contrib
你知道如何解决这个问题吗？