expo/expoweb
1
0
Fork 0
mirror of https://expo.survex.com/repositories/expoweb/.git/ synced 2025-12-08 23:04:35 +00:00
Code Issues Packages Projects Releases Wiki Activity

More hut netconfig

Browse Source
This commit is contained in:
Philip Sargent
2023-03-30 03:18:37 +01:00
committed by Wookey
parent f4ac133f62
commit 9f5aa03fe9
6 changed files with 667 additions and 37 deletions
Download Patch File Download Diff File Expand all files Collapse all files

139
handbook/computing/netconfig.html
View File

@@ -28,7 +28,7 @@ still upright and have not been knocked sideways.
<h3>Expo laptops</h3>
<p>Both expo laptops Crowley and Aziraphale use DHCP over wifi to get an IP4 address and the identity of a DNS nameserver. Neither laptop has any other configuration.
<p>Both expo laptops Crowley and Aziraphale use DHCP to get an IP4 address and the identity of a DNS nameserver. Neither laptop has any other configuration.
<p>If you connect your laptop or phone to the potato hut wifi you will connect in the same way.
<h3>The Gasthof Wifi</h3>
@@ -48,19 +48,22 @@ still upright and have not been knocked sideways.
<p>When the netbook powers up, the script <var>/etc/init.d/fakenet</var> runs which sets everything going for the first time.
<h4>wicd</h4>
<p>The netbook needs to have its persistent networking set up correctly <i>in addition to the other scripts</i>. This
is the <a href="https://launchpad.net/wicd">wicd</a> gui program that has an icon in the top-right of the sceen in the
system panel. (Or search in all applications in the Internet section for the wicd application). Set the checkboxes so
that the netbook does not connect to any network except the StaudnGast wifi network, and also tick the 'automatically
reconnect' checkbox for the "StaudnGast" network.
<h4>Netgear WNDR4000</h4>
<h4>Wifi/router Netgear WNDR4000</h4>
<p>The Netgear ethernet/wifi hub holds the radio transceiver that provides the wifi coverage inside the potato hut.
It is configured using its web control panel (https://192.168.1.1). It has an <a href="https://manualmachine.com/netgear/wndr4000/816208-user-manual/">online manual</a> but it needs no configuration at all during expo. Just turn it on at the beginning of expo and off again at the end.
It has an <a href="https://manualmachine.com/netgear/wndr4000/816208-user-manual/">online manual</a> but it needs no configuration at all during expo. Just turn it on at the beginning of expo and off again at the end.
<p>The webpage control panel (which you should never need or touch) is accessed by connecting a laptop to the wifi or using the <var>expo laptop</var> on the ethernet and bringing up a web browser to <a href="http://192.168.1.1">http://192.168.1.1</a> with username 'admin' and the usual expo cavey:beery password. The password is also written on the underneath of the box.
<h5>TL-WR841N</h5>
<figure class="onright" >
<a href="WR841N.jpg"><img border=1 src="WR841N.jpg"></a>
<br><figcaption>TL-WR841N sockets and switches</figcaption>
</figure>
<p>In 2023 we will also have a backup wifi/router in Austria, a £20 <a href="https://www.expertreviews.co.uk/tp-link/1401766/tp-link-tl-wr841n-review">TL-WR841N</a> belonging to Wookey which is configured identically to the Netgear device except that the username is 'root' not 'admin'. It is to be used only if the Netgear breaks.
<p>One important difference is that the ethernet cable from the netbook is plugged into the blue socket on the WR841N (it is yellow on the Netgear), and the 4 white sockets on the Netgear are 4 yellow sockets on the WR841N. A word of warning: the WR841N has been flashed with new firmware and so any documentation you may read in online manuals for it will be wrong: notably the reset and wifi on/off buttons don't have any effect, and the lights don't flash in the way the manuals say they do. There is also no USB socket, no IP6, no 5Ghz, slower ethernet (100Mbps not 1Gbps) and the wifi range out to the tents is worse than the Netgear wifi.
<h4>IP6</h4>
<p>While you can use 5Ghz wifi and IP6 to connect within the hut, there is no IP6 connectivity to the external internet. Sorry. We are dependent on the Gasthof system for this.
<p>While you can use 5Ghz wifi and IP6 to connect within the hut, there is no IP6 connectivity to the external internet. Sorry. We are dependent on the Gasthof system for this. Use a phone and data roaming if you want it.
<h3>4 different 'networks'</h3>
<p>To understand how the network is configured, you need to realise that we have to manage these different 'networks':
@@ -70,7 +73,7 @@ It is configured using its web control panel (https://192.168.1.1). It has an <a
<li><samp>10.0.x.y</samp> The network on the short bit of cable connecting the netbook with the Netgear box.
<li>The network on the longer length of cable connecting the Netgear box with the <var>expo laptop</var> (and sometimes the printer).
</ul>
We bridge the hut wifi with the hut ethernet cable to the <var>expo laptop</var> so they are both <samp>192.168.1.x</samp>, but this is a matter of choice. This is configured in the netbook config files.
We bridge the hut wifi with the hut ethernet cable to the <var>expo laptop</var> so they are both <samp>192.168.1.x</samp>, but this is a matter of choice. This is configured inside the wifi/router using the webpage control panel.
<h4>Where the DNS happens</h4>
<p> DNS is what connects a computer name (such as <var>expo.survex.com</var>) with an internet address (such as <samp>78.129.164.125</samp>). To make the internet work, we need to tell every laptop and phone where to find a DNS nameserver, or what machine to ask in order to get DNS queries forwarded to a DNS nameserver.
@@ -84,34 +87,96 @@ We bridge the hut wifi with the hut ethernet cable to the <var>expo laptop</var>
<li>2022 : in the Netgear box.
</ol>
<p>1. The benefit of doing it in the Netgear box is that you get to play with a graphical web interface not text files. But also you can test that the Netgear box is working separately from everything else.
<p>2. The benefit of doing it in the netbook is that all the configuration is in the same place, and you only have to learn one way of doing things instead of having to use text files <em>and</em> a web interface. Aslo, by making the Netgear box completely dumb, it is swap-replaceable if it dies with no reconfiguration required.
<p>2. The benefit of doing it in the netbook is that all the configuration is in the same place, and you only have to learn one way of doing things instead of having to use text files <em>and</em> a web interface. Also, by making the Netgear box completely dumb, it is swap-replaceable if it dies with no reconfiguration required.
<p>The DHCP is configured to issue IP addresses with <samp>x</samp> between 2 and 199, i.e. laptops and phones will get IP addresses between <samp>192.168.1.10</samp> and <samp>192.168.1.199</samp>. These may change after 12 hours.
<h4>Static addresses</h4>
<p>The netbook has two network interfaces: the Alfa wifi antenna (which has an address issud by the Gasthof wifi system) plugged into a USB socket, and its ethernet cable socket which is configured to have the address <samp>10.0.1.2</samp>.
<p>The Netgear box has its yellow ethernet cable socket set to the address <samp>10.0.1.1</samp>. The four other ethernet sockets are all on the address range <samp>192.168.1.x</samp> and the wifi network interface is set to <samp>192.168.1.1</samp> on the same network range.
<p>The netbook has two network interfaces: the Alfa wifi antenna (which has an address issued by the Gasthof wifi system) plugged into a USB socket, and its ethernet cable socket which is configured to have the address <samp>10.0.1.2</samp>.
<p>The Netgear box has its yellow ethernet cable socket set to the address <samp>10.0.1.1</samp>. The four other ethernet sockets are all on the address range <samp>192.168.1.x</samp> and the wifi network interface is set to <samp>192.168.1.1</samp> also in the network <samp>192.168.1.x</samp>.
<p>So the ethernet cable between the Netgear box and the netbook is <samp>10.0.1.1</samp> at the Netgear end and <samp>10.0.1.2</samp> at the netbook end. Nothing else uses any number like <samp>10.0.x.y</samp>.
<h4 style="color: red">When it all goes wrong</h4>
<p>If everything is working between devices in the hut, but there is no internet access, then the <b>first thing to check</b> is that
the black WiFi antennae on the small black Alfa box are still upright and have not been knocked sideways.
<p>The next thing is to take a phone out to the road and try to connect directly to the Gasthof wifi. This is to check that the Gasthof is on the internet and that the problem is not between the Gasthof and the rest of the world.
<p>You test whether the internet is running by trying to visit <a href="http://www.google.com">www.google.com</a> or
<a href="https://github.com">github.com</a>.
<p>The netbook attempts a reconnection every 60 seconds, so wait at least 2 minutes before doing anything. That is because when the netbook attempts a full reconnection it can take nearly a minute to rebuild everything.
<p>Test whether the netbook is actually running and responding by sitting at the <var>expo laptop</var> and logging into the netbook remotely. Do this in a terminal window:
<pre><code>ssh expo@10.0.1.2</code></pre>
or
<pre><code>ssh expo@tclaspire3.hut</code></pre>
<p>If you get a login prompt, the netbook is running. It is a slow machine so do not expect this to be instant.
<p>Login (as user 'expo' using the cavey:beery password) and type this at a prompt:
<pre><code>/root/fakenet/runfakenet</code></pre>
which will run the script to reconnect. This may take a minute to have the desired effect.
<p>If you didn't get a prompt when you attempted to login from the <var>expo laptop</var> then you will need to do the same thing but actually on the netbook keyboard. While you are at it, it would be a good idea to re-boot the netbook first by typing this on the netbook keyboard first, and waiting for it to re-boot:
<pre><code>shutdown --reboot</code></pre>
<p>You may also need to re-enable wicd, see below.
<p>If it keeps failing, then maybe the <var>cron</var> system which re-triggers it every 60s is not working. That is probably a symptom of something more much more serious wrong with the netbook if you have already re-booted it. Try re-booting it again and this time be more patient. <em>Report this</em> to a nerd and <em>write a record of the problem in the expo logbook</em>.
<h4>wicd</h4>
<p>The netbook needs to have its persistent networking set up correctly <i>in addition to the other scripts</i>. This
is the <a href="https://launchpad.net/wicd">wicd</a> gui program that has an icon in the top-right of the sceen in the
system panel. (Or search in all applications in the Internet section for the <var>wicd</var> application). Set the checkboxes so
that the netbook does not connect to any network except the StaudnGast wifi network, and also tick the 'automatically
reconnect' checkbox for the "StaudnGast" network.
<h2>The scripts</h2>
<p>
<p>For the curious or desperate, here is how the scripts actually work.
<p>The <var>/root/fakent/expo/hosts</var> file is just two lines:
<pre><code>10.0.1.2 tclapsire3
10.0.1.1 router
</code></pre>
<p>The file that configures the wifi is the file <var>/root/fakent/expo/hostapd.conf</var>
<pre><code>interface=wlan0
driver=nl80211
ssid=tattyhut
hw_mode=g
channel=1
macaddr_acl=0
ignore_broadcast_ssid=0
auth_algs=1
wpa=3
wpa_passphrase=CAVEYBEERYPASSWORD
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP
</code></pre>
where CAVEYBEERYPASSWORD is our usual expo password. In 2022 this capability was configured by the Netgear control panel, not by this file on the netbook.
<strike>
<p>Because the netbook is on a different network from the laptops connecting to the hut wifi, you can't directly login to the netbook using <var>ssh</var> to the IP address (ssh expo@10.0.1.2), but you can using its name, so <var> ssh expo@tclaspire3.potatohut</var> should work if everything has been configured correctly.
<p>
This is the address to use for configuring it using ssh when everything else has failed. So to manage the
connection to the Gasthof WiFi you would use
<pre>
ssh expo@192.168.200.100
</pre>
<p>The file that configures the DNS and DHCP is <var>/root/fakent/expo/dnamasq.conf</var> and it is very long with most of the lines commented out with an initial '#', so they are not all listed here. (You can read a copy of it <a href="copy-of-dnsmasq.conf">here</a>). On the netbook 'eth0' is the interface with the antenna (which is actually a USB socket) and 'wlan0' is the ethernet socket interface to the cable to the Netgear box. Some of the more relevant lines are:
<pre><code>interface=wlan0
dhcp-range=192.168.1.10,192.168.1.199,12h
addn-hosts=/root/fakenet/expo/hosts
expand-hosts
domain=potato.hut
no-dhcp-interface=eth0
</code></pre>
Note the line <var>addn-hosts=/root/fakenet/expo/hosts</var> which refers to the first file listed above which defines the names of the machines for the two ends of the cable between the netbook and the Netgear box.
<p>The line that configures <var>crontab</var> to run the fakenet script every 60 seconds is
<pre><code>MISSING
MISSING - need to get this...
</code></pre>
<p>The actual fakenet script is
<pre><code>MISSING
MISSING - need to get this...
</code></pre>
<p> The init script which configures everything when the netbook is booted up is
<pre><code>MISSING
MISSING - need to get this...
</code></pre>
<pre>/root/fakenet/runfakenet
</pre>
This used to need running once or twice a day when the internet stops working, but it was radically fettled in 2022 and so should be much more reliable.
Sometimes you may have to walk over to the blue Acer Aspire netbook and run this script directly by typing on its keyboard
as the network has collapsed so badly that <span style="font-family:monospace">ssh</span> doesn't work.
</strike>
<h3>Historical Notes</h3>
<h2>Historical Notes</h2>
<p>Prior to 2017 we used to run an unconnected local network with our own DNS domain
name "potato.hut", our own server holding all the website and survey data, and published WiFi as SSID "tattyhut".
@@ -125,11 +190,11 @@ pushing the changes to the distributed version control system on
the internet continuously and not to have our own local server. This coincided with a much-improved WiFi service at
the Gasthof. We continued with the wifi service in the hut but now it also connects to the external internet instead of to a 'pretend' internet (which is why the system is called 'fakenet').
<p>In 2018 and 2019 we had good Internet access at basecamp, but the high-gain system was returned to its owner during Covid.
<p>In 2022 Wifi reception from the Gasthof was very poor. The connection script was improved so that dropped connections were restored more quickly. However the basic bandwidth with a cheap antenna was not enough.
<p>In 2018 and 2019 we had good Internet access at basecamp, but the high-gain system was returned to its owner (Sam) during Covid (2020-21). Wookey bought a new one, which proved to not live up to its advertising.
<p>In 2022 Wifi reception from the Gasthof was very poor. The connection script was improved so that dropped connections were restored more quickly. However the basic bandwidth with the new cheap antenna was not enough.
<p>In 2023 a new Wifi device (the Alfa) should restore decent connectivity. We hope this will improve everything to how it was in 2019. However this Alfa has proved to be a right bastard to find the right drivers for. Wookey has had to be inventive in using an Ubuntu PPA to make it work with the Acer Aspire 1.
<p>Also during winter 2023/23 Wookey upgraded the operating system on the Acer Aspire One netbook from whatever ancient Debian it had been running to a decently almost-modern Debian distribution. This required much coaxing. As of 26 March, it is still a couple of Debian versions behind where we would want it to be.
<p>Also during winter 2023/23 Wookey upgraded the operating system on the Acer Aspire One netbook from the ancient Debian Wheezy it had been running to a decently almost-modern Debian distribution. This required much coaxing.
<h4>History of the scripts</h4>
<p>The structure of the system was created by Wookey in 2013 who used the fakenet principle and the netbook to run training sessions for the Cave Survey Group in the UK. [This is why the script has an extra level of parameter setting that might seem necessary: it has 'csg' and 'expo' options, but the two configurations have diverged so much over the years that this is merely a fossil.]