Two elementary questions on LANs

[Timothy Murphy]

Tim wrote:

> On Thu, 2011-06-16 at 22:19 +0200, Timothy Murphy sent:
>> I think I got this wrong too.
>> I am running shorewall on my server,
>> and I forgot to turn iptables off.
> 
> Whenever I see mentions of "turning firewall off," that's a red flag, to
> me.  Is shorewall an independent thing, or is it a configurator for
> iptables?  Had turning off iptables turned off your firewall, or has it
> handed control of it over to something else?

It handed control over to shorewall.
The probability of my making a mistake while configuring iptables
is at least a hundred times higher than the probability that Tom Eastep
(who wrote and runs shorewall) made a mistake in setting it up.

>> I see now I can go to Manage Connections in NM,
>> and specify the name servers.
>> Now NM seems to leave /etc/resolv.conf alone.
>> Previously I was just adding the nameservers by hand.
> 
> Adding them to what, though?  That file?

To /etc/resolv.conf .
I'm probably in a minority of 1, but I don't think applications
should edit config files without telling you.

>>>> Changes to the routing table on the latter, eg changing the default
>>>> gateway, do not seem to come into force until I re-boot.
> 
>>> How are you trying to bring about the gateway change?  Are you bringing
>>> its interface down and back up again, to force a configuration reload?

No, I didn't.
But that wasn't necessary on Fedora;
the change comes into force as soon as the route command is given.

>> I'm never quite sure if we are allowed to use the network service.
> 
> Your organisation won't let you, or do you mean technical
> considerations?

I was being slightly impish, and referring to the rulers of Fedora.
As far as I can see, NM has become a standard part of Fedora,
and the network service seems to be withering away.
I never know if programs like system-config-network 
will assume that you are running NM.
I don't particularly mind; NM and network used to be equally bad,
in my experience, but NM has steadily improved and now is quite reliable.


-- 
Timothy Murphy  
e-mail: gayleard /at/ eircom.net
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland