1、下载软件包tcpd，并在/var/cache/apt/archives目录中查看。

root@educoder:~# apt-get install -d tcpd
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following NEW packages will be installed:tcpd
0 upgraded, 1 newly installed, 0 to remove and 96 not upgraded.
Need to get 23.6 kB of archives.
After this operation, 96.3 kB of additional disk space will be used.
Get:1 http://ports.ubuntu.com/ubuntu-ports focal/universe arm64 tcpd arm64 7.6.q-30 [23.6 kB]
Fetched 23.6 kB in 1s (19.1 kB/s)  
Download complete and in download only moderoot@educoder:~# cd /var/cache/apt/archives
root@educoder:/var/cache/apt/archives# ls
lock  partial  tcpd_7.6.q-30_arm64.debroot@educoder:/var/cache/apt/archives# cp tcpd_7.6.q-30_arm64.deb /data/workspace/downloadfiles

2、解压安装软件包。

dpkg -i /data/bigfiles/tcpd_7.6.q-30_arm64.deb