To use SLIP or PPP, you have to configure some basic networking
features as described in the previous chapters. You must set up the
loopback interface and configure the name resolver. When connecting to
the Internet, you will want to use DNS. Your options here are the same
as for PPP: you can perform your DNS queries across your serial link
by configuring your Internet Service Provider's IP address into your
/etc/resolv.conf file, or configure a
caching-only name server as described under Section 6.3.4,” in Chapter 6."