Bullseye armel is out of LTS. This means it's no longer listed in the
Release file at deb.debian.org
It is still listed at archive.debian.org.
However, I can't find bullseye-security there.
On Saturday 31st August 2024, Debian 11.11 was released. Did this mean
that everything that was in bullseye-security was rolled into the main
archive and so there's no reason to even look for debian-security any
more except for the archs still under LTS?
The snapshot at 05:36 on that date is the last one that contains armel
in debian-security.
Debian Long Term Support (LTS) is a project to extend the lifetime of
all Debian stable releases to (at least) 5 years. Debian LTS is not
handled by the Debian Security and Release teams, but by a separate
group of volunteers and companies interested in making it a success.
It's slightly weird because I should have hit the same issue for buster
in the past. It's not clear to me what the correct combination of
archive.debian.org and deb.debian.org is currently and whether it needs
to differ by arch. In about a year everything will be archive only
(which is where buster is now)
Jeff