Apt-get -d

apt-get -d install PACKAGE_TO_DOWNLOAD

apt-get -d install iperf
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
  aufs-tools cgroupfs-mount containerd.io docker-ce-cli pigz
Use 'apt autoremove' to remove them.
The following NEW packages will be installed:
  iperf
0 upgraded, 1 newly installed, 0 to remove and 108 not upgraded.
Need to get 76.5 kB of archives.
After this operation, 213 kB of additional disk space will be used.
Get:1 http://archive.ubuntu.com/ubuntu focal/universe amd64 iperf amd64 2.0.13+dfsg1-1build1 [76.5 kB]
Fetched 76.5 kB in 1s (59.0 kB/s)
Download complete and in download only mode

/var/cache/apt/archives/

See also

• APT: wajig, apt-cache, add-apt-repository PPA, apt [ install | remove |purge | show | list | changelog | update | upgrade], do-release-upgrade, apt-mark, apt full-upgrade, sources.list, APT Automatic updates, unattended-upgrade, apt-transport-https, apt-get update, /etc/apt/, /etc/apt/apt.conf.d/50unattended-upgrades, /etc/apt/apt.conf.d/, /etc/apt/apt.conf.d/20auto-upgrades, apt-file, apt-utils