[CentOS] Questions about network configuration

Hi,

I'm currently reading chapter 13 of the RHEL Deployment Guide, and 
taking some notes. I have a few minor questions:

/etc/sysconfig/network

According to the doc: "This file specifies routing and host information 
for all network interfaces."

Here's how mine looks like:

--8<-----------------
NETWORKING=yes
NETWORKING_IPV6=yes
HOSTNAME=fujitsu.zuhause
GATEWAY=192.168.1.254
--8<-----------------

NETWORKING_IPV6=   -> I wonder if I can switch that to 'no', since I 
simple don't use IPV6. Will some apps mysteriously refuse to work when I 
do this? (You never know...)

HOSTNAME=...   -> this looks like a redundancy with information provided 
in /etc/hosts. So what is it for? Can it be left out?

GATEWAY=...   -> another redundancy, since it's also to be found in 
/etc/sysconfig/network-scripts/ifcfg-<interface>. Leave it out if it's 
in the individual interface scripts?

More questions to come, but here's a first bunch :o)

Cheers,

Niki

PS: I've started on Linux with Slackware (7.1), hence a habit of 
configuring my system with Vi rather than some configuration helpers. 
Even if they do the job as good, it's just a matter of personal taste 
and habits.
-- 
Dyslexics have more fnu.