[PLUG] Understanding Networking Components

[Rich Shepard]

On Sat, 31 Mar 2012, Neal wrote:

> The point of my question was to verify that a default gateway was set
> properly on the WLAN. That is, the default WLAN gateway was set to a valid
> address on the WLAN subnet. If it's not you won't be able to access any IP
> (including DNS) that's not on the WLAN subnet.

    Just back from another unsuccessful attempt at the coffee shop.

    When the system boots it connects automatically to the shop's wifi server.
The ESSID is 'WEBbeans-Silk Espresso', 'ifconfig wlan0' returns the IP
address 10.5.70.104, broadcast address 10.5.70.255, and netmask
255.255.255.0.

    The kernel routing table (displayed in response to 'netstat -r') has 2
pairs of entries (default and broadcast) for the eth0 and wlan0 interfaces.
For wlan0,
default		10.5.70.1
10.5.70.0	*

    /etc/resolv.conf -- SET BY THE WIRELESS SERVER -- shows
nameserver 8.8.8.8
nameserver 8.8.4.4

These are Google's nameservers so the WEBbean.com network does not provide
their own DNS servers.

    The access card instructions are to make the connection, then invoke a
browser to enter the provided password and accept their terms and conditions
of use to be allowed access to the 'Net.

    This is where something is broken. No Web page loads with firefox-11.0,
opera-10.61, links, or lynx. Can't load the access page, www.webbeans.com,
or any other page.

    As before, cannot ping any address on the local Class A network (nor any
world-addressible domain name or IP address). Trying to ping the gateway
(10.5.70.1) results in 'Destination unreachable'; trying the namesever
(8.8.8.8) results in 'Destination not reachable'.

    With an IP address, DNS servers, and gateway all assigned by the local
server, what might inhibit loading the 'Net access control page or any other
web page?

Rich