• Table of contents
• Managing OpenWRT
  • Installing and configuring Jool
  • Enabling routing with router advertisements
  • Enabling SSH access on wan
  • Resetting to factory default
  • Installing and configuring an APU as a PIB with OpenWRT
    • Installing openwrt (squashfs) on APU details
    • Defaults after Openwrt installation
  • Setting up the GL-INET GL-MT300N-V2
  • Managing QMI based LTE devices
  • Managing static IPv6 addresses
  • Temperature sensor support

Managing OpenWRT¶

Installing and configuring Jool¶

• You can use one of the known NAT64 prefixes from our networks (LINK!)
  • In the example below this is 2a0a:e5c0:2:10::/96
• You need to have a /96 (or better: /64) routed to the openwrt
  • In the example below this is 2a0a:e5c0:17:1::/96

opkg install kmod-jool
opkg install jool-tools

# Load the kernel module
modprobe jool_siit

# The range which will be the target for the 2nd NAT (if needed to reach a v4 ip)
jool_siit -6 2a0a:e5c0:2:10::/96

# Pick a v6 range to translate TO and a v4 range to translate from
jool_siit -e -a 2a0a:e5c0:17:1::/96 192.168.61.0/24

# Accept Router Advertisements to keep the default address
sysctl -w net.ipv6.conf.all.accept_ra=2
sysctl -w net.ipv6.conf.default.accept_ra=2
sysctl -w net.ipv6.conf.eth0.accept_ra=2
sysctl -w net.ipv6.conf.br-lan.accept_ra=2

Enabling routing with router advertisements¶

• By default ipv6 forwarding is on (good!)
• By default accept_ra is 0
  • This does not set the route properly into the kernel -> routing is broken
• Need to modify accept_ra to 2

Enabling SSH access on wan¶

Enable it in the web interface

 $URL/cgi-bin/luci/admin/system/admin/dropbear 

OR

Dropbear uci var (not tested):

    option GatewayPorts 'on' 

Resetting to factory default¶

• See https://openwrt.org/docs/guide-user/troubleshooting/failsafe_and_factory_reset

firstboot -y && reboot now

Installing and configuring an APU as a PIB with OpenWRT¶

• Get the x86 64 SQUASHFS image
  • https://downloads.openwrt.org/releases/19.07.3/targets/x86/64/
  • combined-squashfs.img.gz
• Gunzip it
• dd it it an usb stick
• Boot the usb stick on the APU
• When booted, wget it on the APU and write it over /dev/sda

wget ... -O - | gunzip > /dev/sda

• Configure it using pib-setup.sh from ungleich-tools
• Create a network on the VPN server

Installing openwrt (squashfs) on APU details¶

opkg update

• Install SSL certifaicates

opkg install libustream-openssl ca-bundle ca-certificates

• check the time and date if it is not correct, modify the time and date as follows
  

  date -s YEARMONTHDATETIME 
  

• Flashing the squashfs openwrt image into the APUs SSD (adjust to the correct version)

wget -O - http://downloads.openwrt.org/releases/19.07.3/targets/
x86/64/openwrt-19.07.3-x86-64-combined-squashfs.img.gz | gunzip > /dev/sda 

Defaults after Openwrt installation¶

• eth0 = WAN
• eth1&2 = LAN

Setting up the GL-INET GL-MT300N-V2¶

• Go to advanced and flash the standard image
• Link: https://openwrt.org/toh/gl.inet/gl.inet_gl-mt300n_v2

Managing QMI based LTE devices¶

Debug commands:

uqmi -d /dev/cdc-wdm0 --get-signal-info
uqmi -d /dev/cdc-wdm0 --get-data-status
uqmi -d /dev/cdc-wdm0 --get-current-settings
uqmi -d /dev/cdc-wdm0 --get-capabilities

uqmi -d /dev/cdc-wdm0 --get-imei

# get network cell / status
uqmi -d /dev/cdc-wdm0 --get-serving-system       

# get networks in range
uqmi -d /dev/cdc-wdm0 --network-scan

Reset (might help to clear the NETWORK_REGISTRATION_FAILED error?)

/sbin/uqmi -d /dev/cdc-wdm0 --set-device-operating-mode offline
/sbin/uqmi -d /dev/cdc-wdm0 --set-device-operating-mode reset
/bin/sleep 20
/sbin/uqmi -d /dev/cdc-wdm0 --set-device-operating-mode online
/sbin/uqmi -d /dev/cdc-wdm0 --set-autoconnect enabled
/sbin/uqmi -d /dev/cdc-wdm0 --network-register

• See also: https://openwrt.org/docs/guide-user/network/wan/wwan/ltedongle

Managing static IPv6 addresses¶

If using a statically routed IPv6 network, the default RA mechanism does not set an outgoing route by default. This is a bit different from "regular" Linux:

• openwrt uses user space odhcp6c
• for openwrt we need to setup a "static default route"
  • do not forget to select the interface in the list
• Default Linux on the other hand needs to use accept_ra=2 if ipv6 forwarding is on
  • This also works on openwrt, but it is conflicting/not the correct way to do
• TL;DR If using openwrt with static IPv6 addresses, add a static IPv6 default route

Alternative (currently untested) approach:

instead of hardcoding the subnet in lan, add it as "option ip6prefix" to your wan6/dhcpv6 interface
in lan merely add "option ip6assign 64" or however much bits you want to redelegate
that should make odhcp6c/netifd aware of the additional prefix and factor that into the default route coverage
it should work as if the prefix were received via dhcpv6-pd

(Thanks to jow in #openwrt)

Temperature sensor support¶

We are using "temper" based usb temperature sensors. They are read using temper-py.
The default setup is to write to /www/temperature.txt which allows the temperature to be read from the standard webserver.

So if you own a VIIRB/VIWIB/other OpenWRT device using the openwrt-add-temper you can see the temperature on http://ip-of-the-device/temperature.txt.

It is refreshed every 5 minutes.