Bionic 18.04 LTS. Apt 1.6.12. ~# time apt update real 0m5.059s real 0m4.981s Okay, adding Focal 20.04 LTS repo. apt install -y apt, got apt 1.9.10. r

Bionic 18.04 LTS. Apt 1.6.12. ~# time apt update real 0m5.059s real 0m4.981s Okay, adding Focal 20.04 LTS repo. apt install -y apt, got apt 1.9.10. real 0m7.222s real 0m6.924s It fetches the InRelease files, all of them seem to have an ETag header, but probably Apt doesn't feel that it can rely on those for some reason. But using `apt -o Debug::Acquire::http=on update` we see that it depends on the "If-Modified-Since" request headers. And many of the repos just return 304. There doesn't seem to be a config setting for increasing the number of outgoing connections either. So even if it gets just 304 responses it still does the "Reading package lists... Building dependency tree" part, which is slooow.