[Discuss] networking problem

[gaf at blu.org (Jerry Feldman)]

On 11/22/2011 11:23 AM, j. daniel moylan wrote:
> i've recently installed ubuntu 10.10 on my asus eee pc 1005ha.  it gave me
> warning messages on bootup:
>
>   waiting for network configuration
>   waiting  up to 60 more sec for network configuration
>   booting system without full network configuration
>
> sure enough, the builtin wireless n didn;t come up.  i tried the
> networkmanager icon, and that came up with the first four lines light
> grey.  perservering, i punched the bottom line "edit connections", did
> that, and saved it but no network came up. i tried /etc/init.d/networking
> restart and that indeed brought up the network 192.168.0.103 as shown by
> ifconfig.  however that issued a warning that the command was deprecated
> and that everything might not come up (but no mention of the favored
> command).  none the less, things seemed to work fine -- the browser
> connected as desired, mutt worked and i was happy though i needed to do the
> init.d thing each time i booted.
>
> today, i was able to bring up 192.168.0.103, but only locally. i can ping
> 192.168.0.1 but can't seem to get out past the local net.  firefox doesn't
> connect out and email doesn't work.
>
> any suggestions would be warmly appreciated.
A few issues.
If you can physically connect to your LAN, things should work.
First, are you using a static IP or a dynamic IP.
Secondly, make sure that your netmask is properly set to 255.255.255.0
(for 192.168.0)
Third, if you have a static IP make sure that 192.168.0.1 is set for
your gateway
Fourth, if you have a static IP, set up your DNS in your network options.

If you have a dynamic IP, make sure that you have it set to give you an
automatic DNS.

You can certainly update /etc/resolv.conf manually, but Network manager
will routinely overwrite it.
The important thing here is to take a list at your default route by
using the command 'netstat -nr' or 'route'
You want to make sure your default route (0.0.0.0) points to your router.
Then test the network. ping the router and/or any other system on your
LAN by ip address.
Then ping a system outside of your LAN by IP address. BLU is 216.235.254.231
If you can ping an outside address, the your routing table is ok. If you
can ping by ip address and not by name, then the DNS is not resolving.
Some ISPs change their DNS servers occasionally. Your router should have
the proper DNS servers. I normally have my router as my primary DNS
since I use a static IP at home, so if Comcast changes DNS servers, the
router will pick it up. I usually have a third DNS as a well known external.

Note that changing your routing table and resolv.conf by hand is not
really desirable when using network manager these days.

-- 
Jerry Feldman <gaf at blu.org>
Boston Linux and Unix
PGP key id:3BC1EB90 
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