Uncategorized – Page 27

Running Ubuntu Linux on Bleeding Edge Hardware: Lenovo E14 Gen 4

In the past, I liked buying used notebooks and use them as my day to day workhorses. It felt good from an environmental point of view and they were significantly cheaper compared to new notebooks, particularly when it came to business notebooks like the Lenovo Thinkpad series. But in recent years, prices for used notebooks have significantly increased, while the performance gap between 3-4 year old computers and current models has significantly widened. So when I recently had some trouble with my AMD based Lenovo X13 Gen 1 (I’ll have a separate post on that), I had to get a new spare notebook and was wondering which one to buy.

After some deliberation, I decided to go for a Lenovo E14 Gen 4, which came with an AMD Ryzen 5 5625U. This processor is from early 2022, and this particular notebook started shipping about half a year ago (March 2022). So how would my production operating system based on a 2 year old Ubuntu 20.04 work on this device? Also, the E-series is the low cost line of the Thinkpad series, so I was wondering how it would do from a performance and connectivity point of view.

When All Else Fails – The Garmin InReach Mini 2 – Part 4: Will It Work In Urban Environments?

In this part of the ‘When All Else Fails’ series, I’ll have a look how the Garmin InReach Mini 2 works in urban scenarios. The device is advertised as a satellite communication tool for adventurers in the wilderness, which is quite a different environment compared to my use case in mostly urban canyons. As I couldn’t find any information of how well messages can be sent and received there, I was anxious to find out.

The catch of the Iridium network is that there are relatively few satellites. Despite being in a low earth orbit at an altitude of around 780 km, the satellites are still far from the surface. That makes it tough for a handheld device with only a small antenna and very limited transmit power to send and receive messages. Also, satellites are often very low on the horizon, so just being outside in a deep urban canyon might also be problematic. Fortunately, things turned out much better than I thought.

When All Else Fails – The Garmin InReach Mini 2 – Part 3: Pricing and Message Handling

In this part, I’d like to muse a bit on Garmin’s pricing of the InReach service for my use-case and the general procedure of sending and receiving messages. While Garmin’s main application for InReach is outdoor communication and tracking in the wilderness, my use-case is to be able to communicate with far away family members when terrestrial networks fail, e.g. during a larger scale power outage. In practice, that means I want to be able to communicate between two InReach devices, or, if terrestrial networks still work at one side, I’d like to communicate between one InReach device and a mobile phone via SMS or email on the other side. In other words, I’m not interested in 2 minute periodic location information being sent or emergency center communication. However, getting the GPS coordinates from which a message is sent is a nice bonus.

When All Else Fails – The Garmin InReach Mini 2 – Part 2: Activation

Let’s get back to the Garmin InReach Mini 2. In part 1, I’ve given a general overview of how satellite messaging services works with the device in general. In this part, I’ll have a closer look at how to get started and how long it takes to activate a device.

Once you have the device in your hand and Internet connectivity is available, it can be activated in just a few minutes and the device can then be used immediately. To work, the device needs to be tied to a subscription. Garmin has several types of subscriptions. The cheapest yearly subscription includes unlimited preset messages and 10 outgoing or incoming self composed messages with up to 160 characters and costs around 15 euros per month. In addition there’s a 30 to 40 euro initial activation charge. More about that in a follow-up post.

When All Else Fails: The Garmin InReach Mini 2 – Part 1

The times are getting stranger and stranger. Only a few years ago, I didn’t worry too much about scenarios which would prevent me from communicating with members of the household while any of us were traveling. But the world has changed massively in the past few years, and at least from a European point of view, I can no longer ignore scenarios of prolonged power and network outages. Whether that’s likely or not is hard to say but I can’t just shrug it off anymore. So I was looking for a way how I could keep in touch ‘when all else fails’.

Activating Comments Again

Earlier this year, I had to deactivate comments on this site, as there was just too much spam coming in and it became a daily pain to remove it. I hoped that this would only be a temporary measure, because even though there is relatively little feedback, I still value it very highly. However, when I switched comments back on some time ago, the avalanche simply resumed. So I disabled comments again and started to look for solutions. What I wanted to have is an anti-spam system that didn’t require external help. But I couldn’t come up with something that would fit the bill. So I decided to give Akistmet a try, an anti-spam tool from the creators of WordPress. It’s not a third party plugin but it does require data exchange with their servers. So I’m not entirely happy, but let’s see how that goes.

Venice Network Notes – Viva La Fibre!

From Vienna, I moved on to Venice and since I stayed for some days, I could also take some time to have a closer look at how the 4G/5G networks perform in this city. Venice is obviously quite a special place and the first thing I noticed from a network point of view is that there are very very few cellular antennas visible in the city. Cellmapper shows the locations of the cell sites it knows and from their distance one could assume that things should work quite well. But the reality on site was a rather mixed experience.

Changing IPv6 Backhaul While Tethering

Recently, I’ve been traveling with a Dual-SIM smartphone, which I also use for Wi-Fi tethering my notebook. I can use both SIM cards from different network operators for Internet connectivity and can switch back and forth while Wi-Fi tethering remains active. This is particularly useful while roaming, as the SIM cards are usually connected to different local networks in the roaming country (VPLMNs in 3GPP parlance). If the signal of one network is weak at one location, there’s a good chance the other is better, so no manual network reselection is required. Both home network operators support IPv6, so I was wondering how the smartphone manufacturer has implemented the notification to the notebook that the IPv6 prefix and the IPv6 DNS server address have changed when I switch between the SIM cards!?

The Reverse Home Server Backup

Today, I realized that the mobile Internet while on the move has become fast enough to allow backing-up data residing on servers at home to an external hard drive connected to my notebook while traveling. This is a bit of a strange scenario, but let me explain:

Bind9 DNS: Follow the IPv6 Filter

Yes, I’m an IPv6 fan and I strive to reach a good balance between running my self-hosted services on an IPv4 / IPv6 dual-stack and simplicity of configuration and maintenance. One service that had some issues in the past with IPv6 was OpenVPN. Perhaps things have gotten better but when I first installed the service many years ago, getting IPv6 through the tunnel just didn’t work. So I have an IPv4-only OpenVPN server at home and I have to make sure there is no IPv6 ‘leakage’ outside the tunnel if the local connectivity offers IPv6.

The answer to the problem was to install the bind9 DNS server and send configuration information to client devices during the VPN tunnel establishment to only use this DNS server. To prevent IPv6 leakage, I configured that DNS server to send empty responses to AAAA DNS requests. The fun part: This seems to be an ‘unloved’ feature in bind9 and so the way this is configured has changed every time I made an Ubuntu OS upgrade. So here’s how to configure bind9 to send empty answers to IPv6 AAAA requests: