Thanks again to everybody for their answers.
My /etc/network/interfaces file is:
# /etc/network/interfaces -- configuration file for
ifup(8), ifdown(8)
# The loopback interface
iface lo inet loopback
# The first network card - this entry was created
during the Debian installation
# (network, broadcast and gateway are optional)
iface eth0 inet static
address 192.168.1.1
netmask 255.255.255.0
network 192.168.1.0
broadcast 192.168.1.255
# gateway 192.168.1.2
There is no following line like,
# iface eth0 inet dhcp
for me to uncomment, but I don't see any reason
why I couldn't just write one, yes?