[PLUG] Can't ping under Ubuntu Intrepid

[Tony Rick]

On Tue, Apr 28, 2009 at 2:41 PM, Tim Wescott <tim at wescottdesign.com> wrote:

> > More cluelessness...
>
>

My 2 cents, use of 'ssh' notwithstanding:

There are some questions not answered here.
1.  How does one choose the addresses for fixed IP Address assignment in a
     home network?
2.  What is the fully qualified domain name of machines behind a router
     in a home network?
3.  If the router isn't a nameserver, what do I use as a nameserver address?

I offer some simple answers from the universe of possibles.

1. The default Local Area Network (LAN) IP address range of a WRT54G
     is 192.168.1.1/255, according to the WRT54G User Guide.  Address
     192.168.1.1 is the default LAN address of the router itself.  All other
     addresses in that range are eligible to be assigned as fixed....BUT...

     If the router is configured to provide addresses via DHCP, (which I
assume
     yours to be, bein' as how it has apparently been happily providing
     addresses all along) the default range of DHCP addresses under its
control
     starts at 192.168.1.100.  That means that, for sanity's sake, the range
of
     eligible fixed addresses is 192.168.1.2/99.   That should be more than
enough
     for a home network.

     This approach is predicated on the assumption that the router is in a
more
     or less default state.   To verify this, you're gonna hafta put on an
admin
     hat and try to talk to the web interface of the router.  Simply enter
the URL
     192.168.1.1 into a browser.   If you get prompted for an admin name and
     password, chances are the default configuration holds (not necessarily
     a good thing).  I you don't get the prompt, you could try 192.168.0.1,
or
     10.0.0.1.   If you want to pursue this track, get a WRT54G UserGuide
     (google, download, free, try
        http://www.linksysbycisco.com/US/en/support/WRT54G/download
     )
     and 'Read More About It'.

     So this gives you a set of choices for fixed IP addresses.  What about
     FQDNs (do not pronounce this phonetically in a room full of kids, else
     be prepared to suffer 'humiliations galore'), acronym for Fully
Qualified
     Domain Names).   On to...

2.  If you have purchased/registered your own domain name, you are home
     free: use that.   If not, make one up.  Since your machines are behind
     a firewall, it shouldn't matter, but discretion is in order.  I use
'.local',
     which was suggested by some site when I was first figuring this stuff
     out.

     Now there's enough to populate a /etc/hosts file (using yours as a
template):

        127.0.0.1        localhost.local localhost
        192.168.1.2    thishere.local   thishere
        192.168.1.3    thatthere.local thatthere

        # The following lines are desirable for IPv6 capable hosts
        ::1     ip6-localhost ip6-loopback
        fe00::0 ip6-localnet
        ff00::0 ip6-mcastprefix
        ff02::1 ip6-allnodes
        ff02::2 ip6-allrouters
        ff02::3 ip6-allhosts

   So what about resolv.conf and the nameservers...

3.  Your ISP has nameservers for you.  They should be already programmed
     into your modem, and possibly even automatically set up in your router,
     as evidenced by the fact that you can ping named hosts in the great
     world ('out among them English').
     Rich's example uses his local nameserver IP address (192.168.55.1), and

     several from aracnet, which I assume to be his ISP.  You should have
     yours around somewhere in some information from your ISP, or they
     might even be in the help section of your ISP's web site, if they are
worth
     their salt.  The 'domain' line in resolve.conf I have found to not be
necessary
     for my simple home use.

For this to effective for your network, all machines that you want to assign
fixed addresses to need to have /etc/hosts and /etc/resolve.conf files
modified
with the same information.

(a bit wordy for 'simple answers').

- tony