If you have some specific packages that you just want to share in your LAN. then you can easily create a local repository with your packages. Here’s how to do it:

1. Install dpkg-dev and apache

# apt-get install dpkg-dev apache2

2. Create a directory under /var/www and copy the packages there:

# mkdir /var/www/debs
# cp <source_dir>/*.deb /var/www/debs

3. Create Package.gz:

# cd /var/www/debs
# dpkg-scanpackages . /dev/null | gzip -9c > Packages.gz

4. Add the following line to /etc/apt/sources.list

deb http://<your_server>/debs ./

(replace <your_server> with the IP or hostname of your server)

5. Update APT

# apt-get update

That’s it! Every time you add/modify a package, rerun steps 3) and 5)