From cedfdc2fd02a08119488a2f3d210d7db4d5868de Mon Sep 17 00:00:00 2001 From: Philip Sargent Date: Mon, 3 Jul 2023 21:09:20 +0100 Subject: [PATCH] ip address updates --- handbook/computing/netconfig.html | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/handbook/computing/netconfig.html b/handbook/computing/netconfig.html index 5620d2a45..19925ad2a 100644 --- a/handbook/computing/netconfig.html +++ b/handbook/computing/netconfig.html @@ -38,7 +38,8 @@ still upright and have not been knocked sideways.

The potato hut wifi

The potato hut wiFi has SSID "tattyhut" with our usual cavey:beery password. Like almost every other wifi anywhere it is running DHCP and allocating IP addresses to your device. -

The DHCP system is issuing IP4 addresses of the form 192.168.200.x where x is a number between 11 and 199 with a lifetime of 48 hours. +

The DHCP system is issuing IP4 addresses of the form 192.168.200.x where x is a number between 50 and 199 +with a lifetime of 12 hours (the backup router, the tp-link WRT41N, issues addresses of the form 192.168.250.x instead).

The Expo laptops acquire a dynamic local address of this form, as does any other laptop or phone connecting to this wifi.

How it works - in words

@@ -59,12 +60,12 @@ Ignore the backup copy in /home/expo/fakenet.
TL-WR841N sockets and switches
-

In 2023 we will also have a backup wifi/router in Austria, a TL-WR841N belonging to Wookey which is configured identically to the Netgear device except that the username is 'root' not 'admin'. It would be good to test this so we could give ARM their WNDR4000 back, and the TP-link router can become expo's. +

In 2023 we also have a backup wifi/router in Austria, a TL-WR841N belonging to Wookey which is configured identically to the Netgear device except that the username is 'root' not 'admin'. It would be good to test this so we could give ARM their WNDR4000 back, and the TP-link router can become expo's.

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 (openWRT) 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 5Ghz, slower ethernet (100Mbps not 1Gbps) and the wifi range out to the tents is probably worse than the Netgear wifi.

Alfa wifi device

The Alfa AWUS036ACH is a high-power external wifi aerial to connect across the campsite to the gasthof. It uses the Realtek RTL8812AU chipset. Annoyingly this does not have a mainline kernel driver so we have to use a dkms driver '8812au'. This is not properly debianized so if you upgrade the kernel on the aspire it has to be rebuilt. The source and the rebuild scripts are in /home/expo/alfa-driver/morrownr. installing the kernel headers for the runing kernel, then running /home/expo/alfa-driver/morrownr/install-driver.sh NoPrompt will update it. -

I recommend not updating the kernel for the duration of expo. +

I recommend not updating the kernel for the duration of expo. We are getting 25-30 Mbit/s download speed with this device at the Acer Aspire netbook (3 July 2023).

IP6

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. @@ -88,17 +89,20 @@ We bridge the hut wifi with the hut ethernet cable to the expo laptop

We have done this in two different ways:

  1. 2017-2019 : in the netbook. -
  2. 2022 : in the Netgear box. +
  3. 2022 : in the router (Netgear or tp-link) box.
-

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. +

1. The benefit of doing it in the router 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.

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 and a web interface. Also, by making the Netgear box completely dumb, it is swap-replaceable if it dies with no reconfiguration required. -

The DHCP is configured to issue IP addresses with x between 10 and 199, i.e. laptops and phones will get IP addresses between 192.168.200.10 and 192.168.200.199. These may change after 12 hours. +

The DHCP is configured to issue IP addresses with x between 50 and 199, i.e. laptops and phones will get IP addresses between 192.168.200.50 and 192.168.200.199. These may change after 12 hours.

The router itself is 192.168.200.1 +

We also have the address 192.168.200.100 reserved for the expo laptop crowley in both routers. +

Interfaces

-

The netbook has two network interfaces: the Alfa wifi antenna (which is 'wlan1' and has an address issued by the Gasthof wifi system using DHCP) plugged into a USB socket, and the netbook's ethernet cable socket (eth0) which is configured to have the address 10.0.1.2. +

The netbook has two network interfaces: the Alfa wifi antenna (which is 'wlan1' and has an address 192.168.2.x issued by the Gasthof wifi system using DHCP) +plugged into a USB socket, and the netbook's ethernet cable socket (eth0) which is configured to have the address 10.0.1.2. wlan0 on the netbook is the internal wifi.

The Netgear box has its yellow ethernet cable socket set to the address 10.0.1.1. The four other ethernet sockets are all on the address range 192.168.200.x and the wifi network interface is set to 192.168.200.1 also in the network 192.168.200.x. @@ -118,9 +122,7 @@ the black WiFi antennae on the small black Alfa box are still upright and have n

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.

Test whether the netbook is actually running and responding by sitting at the expo laptop and logging into the netbook remotely. Do this in a terminal window: -

ssh expo@tclaspire3.potato.hut
-or -
ssh expo@tclaspire3.hut
+
ssh expo@tclaspire3.potatohut
or 
ssh expo@10.0.1.2
(The last of these may not actually work: this is a non-routable IP address.)