Some of the instructions in GLFS require an internet connection, namely in Rustc-1.93.1 and when downloading all the files for a package bundle like LLVM-21.1.8 and Vulkan-SDK-1.4.341.0. Thus, you will need an internet connection on the LFS target, whether in a chroot, TTY, or GUI. Tools for downloading files will be installed in GLFS.
The LFS book covers setting up networking by connecting to a LAN with a static IP address. There are other methods used to obtain an IP address and connect to a LAN and other networks (such as the internet). The most popular method is DHCP.
DHCP stands for Dynamic Host Configuration Protocol. It is a protocol used by many sites to automatically provide information such as IP addresses, subnet masks and routing information to computers. If your network uses DHCP, you will need a DHCP client in order to connect to it.
Systemd provides two daemons for DHCP: one which handles the
network interface, and another that handles DNS resolving
(systemd-networkd and systemd-resolved respectively). The LFS book
covers how to set up both.
You may also be wanting to connect to the internet wirelessly. In
order to do that, you should first configure the kernel to support
that, the instructions for that are
here. After that, you will need a tool to connect to the
internet, suitable ones being
iw,
Wireless Tools, or
wpa_supplicant. You will only need one of those, whichever one
is up to you. Ensure that both the
systemd-networkd and systemd-resolved services are enabled.