News archive December 2018 - Koos van den Hout

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2018-12-30 New GcmWin for Linux 1 year ago
The author of GcmWin for Linux responded quickly to my report of being unable to install gcmwin after installing a new Linux version and made a new version available which does run fine on Ubuntu 18.04. Again my thanks to Roger Hedin SM3GSJ for making GcmWin available.

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2018-12-30 First annoyance with systemd on thompson 1 year ago
On reinstalling thompson I was not sure whether to pick ubuntu (with lots of package support for amateur radio) or devuan (without systemd). I chose ubuntu to keep access to lots of amateur radio packages but as expected the first systemd problem already got me. Names in the internal network with RFC1918 addresses weren't resolvable.

After some searching I found out systemd-resolved had decided the last nameserver advertised via IPv6 was the one to use. As I could not find a lot of information on how to do the ordering I just decided to kick it all out and switch to normal resolving. Some searching found How to disable systemd-resolved in Ubuntu? - ask ubuntu which has the right steps. Back to somewhat normal, the next step is to convince NetworkManager to use IPv6 resolving before IPv4.

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2018-12-28 Serious tropospheric ducting over Christmas 1 year ago
Normally, radio signals travel in a straight line and refraction in the ionosphere only happens on relatively low frequencies (below 30 MHz).

Signals in the 2 meter band (144-146 MHz) don't get refracted in the ionosphere, they just leave earth. But in certain weather conditions with stable high-pressure areas layers can form that reflect these signals back to earth or create ducts in the air where the radio signals travel along the surface for much bigger distances than normal.

For Christmas 2018 there was some troposperic ducting predicted on William Hepburn's Worldwide Tropospheric Ducting Forecast. This site forecasts ducting areas based on predicted weather patterns.

To see the actual distances seen in radio contacts I check VHF propagation map based on APRS reception which uses input from APRS messages with location data received at other sites to find long distance contacts. During the Christmas festivities I checked that site from time to time and saw the big distance signal reports mostly over France, slowly creeping North.

So on 25, 26, 27 and 28 December I ran the radio when possible on 2 meter FT8 and got some new distance records and some new gridsquares in the log. New distance record: 639 kilometer to G4RRA. Several other new calls in the log, some new gridsquares. When visiting the qrz pages of those calls I usually see serious setups with directional antennas so they all do the hard work transmitting in my direction and decoding my signal.

This is all still with the 'simple' vertical for 2m/70cm: a Diamond X-300N on the roof. I wonder what I can do on a good day with a directional antenna and a rotor.

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2018-12-23 I upgraded the 'radio workstation' thompson 1 year ago
As mentioned in New 2 meter distance: 506 kilometers I was still running the old wsjt-x because a newer version requires a newer Linux environment. With a bit of time in the christmas holidays available and more and more things depending on this upgrade I ordered a new disk from Azerty so the reinstallation would be easier. The old linux installation on the radio workstation was several Ubuntu versions old, it was still a 32-bit installation because of earlier hardware compatibility issues and something in D-Bus communication gave lots of errors at bootup, so I expected another upgrade to give me an unavailable system.

The new disk came faster than expected, and I did an install with Xubuntu because I'm ok with the Xfce environment.

One problem is back: the system starts with the two monitors swapped and after the screensaver kicks in the monitors somehow end up in mirrored mode.

And Gcmwin for linux failed in the upgrade since it depends on older libraries. Already reported to the author.

Lots of upgraded software, the most important ones in amateur radio are CQRLOG which showed the well-known MySQL problems until I used the version from the CQRLOG ppa. Everything now works fine and all the earlier confirmations of PSK contacts have been imported. And the trigger that all started this upgrade WSJT-X has been upgraded using the WSJTX General Availability Release ppa.

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2018-12-19 New 2 meter distance: 506 kilometers 1 year ago
Today I had a listen on the 2 meter band with FT8 from wsjt-x 1.9.1, which is currently the near-ancient version but I can't upgrade yet (wsjt-x 2.0.0 requires newer Qt libraries which require a newer linux environment).

But I decoded some signals including a new callsign from Germany. It's always nice to work a new callsign so I answered it and the contact was made after a few tries. Only when I checked the gridsquare and the map I saw that DK1FG is a new 2 meter band distance record for me : 506 kilometers. Looking at that qrz page makes clear why that was possible: on that end 8 stacked 12 element antennes are available for 2 meter DX.

Update 2018-12-21: I just saw wsjt-x packages for other ubuntu versions are available in the WSJTX General Availability Release ppa but the 'oldest' Ubuntu version supported is Ubuntu 16.04.5 LTS 'Xenial'.

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2018-12-14 Afpersingsmail die blijkbaar werkt 1 year ago
Ik kreeg een mail zoals deze Afpersingsmail: Bedreiging voor uw veiligheid! ***@*********.nl is gecompromitteerd. - Fraudehelpdesk.

De tekst leest kwa stijl of de auteur niet echt Nederlands kent en deels hulp heeft gehad van een automatische vertaling of van meerdere mensen die stukjes vertaald hebben.

Het volgen van het bitcoin adres in het mailtje (deels gemaskeerd bij fraudehelpdesk) levert een interresant beeld op: dit levert blijkbaar wel wat op. Als ik de bitcoin rekening opzoek op Bitcoin Address 1PRUG1TrBWKLpvMJYfYXhZVSDagSySqXuz zie ik diverse bijschrijvingen in de afgelopen twee dagen en een afschrijving. De eerste drie bijschrijvingen lijken erg op betalingen in de buurt van de genoemde 35 euro. Maar als ik diep in de transacties duik zonder enige voorkennis van bitcoin zie ik allemaal verwarrende dingen.

Opvallend is wel dat dezelfde wallet dus op meer plekken genoemd is. Daarmee is het traceren van degene die betaald heeft onmogelijk, waardoor het verhaal in de afpersingsmail ook compleet ongeldig is.

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2018-12-07 Trying to kick spamassassin and perl into the 21st century and prefer IPv6 for DNS traffic 1 year ago
Or in short: Perl considered harmful

I want applications to use and prefer IPv6 whenever possible, so I have a /etc/resolv.conf with IPv6 addresses of the nameserver(s) listed first. But I noticed queries from the spamassassin processes still coming in over the legacy IP protocol. Even when listing them in order in /etc/spamassassin/local.cf spamassassin prefers IPv4. And I want it to prefer IPv6 without leaving out IPv4. I like the redundancy but I want to change the preference. Also: I only want to maintain the list of nameservers in /etc/resolv.conf and not in other locations.

I wrote a simple test program to understand what the perl Net::DNS::Resolver is doing. With a standard test program like:
#!/usr/bin/perl -wT

use strict;
use Net::DNS;
my $resolver = new Net::DNS::Resolver();

print join ' ', $resolver->nameservers();

print "\n";
The IPv4 addresses will be listed first, independent of the order in /etc/resolv.conf. Only after changing to:
#!/usr/bin/perl -wT

use strict;
use Net::DNS;
my $resolver = new Net::DNS::Resolver();
$resolver->prefer_v6(1);

print join ' ', $resolver->nameservers();

print "\n";
I will see the IPv6 resolver listed first. But now to convince spamassassin to do the same. Browsing the Net::DNS::Resolver shows the RES_OPTIONS="inet6" option but does not document it. This option confuses spamassassin when starting:
export RES_OPTIONS="inet6"
root@gosper:/etc/default# service spamassassin restart
Restarting SpamAssassin Mail Filter Daemon: Bad arg length for NetAddr::IP::Util::mask4to6, length is 128, should be 32 at /usr/lib/x86_64-linux-gnu/perl5/5.24/NetAddr/IP/Lite.pm line 647.
Compilation failed in require at /usr/lib/x86_64-linux-gnu/perl5/5.24/NetAddr/IP.pm line 8.
BEGIN failed--compilation aborted at /usr/lib/x86_64-linux-gnu/perl5/5.24/NetAddr/IP.pm line 8.
Compilation failed in require at /usr/share/perl5/Mail/SpamAssassin/Util.pm line 70.
BEGIN failed--compilation aborted at /usr/share/perl5/Mail/SpamAssassin/Util.pm line 70.
Compilation failed in require at /usr/share/perl5/Mail/SpamAssassin/Conf.pm line 85.
BEGIN failed--compilation aborted at /usr/share/perl5/Mail/SpamAssassin/Conf.pm line 85.
Compilation failed in require at /usr/share/perl5/Mail/SpamAssassin.pm line 71.
BEGIN failed--compilation aborted at /usr/share/perl5/Mail/SpamAssassin.pm line 71.
Compilation failed in require at /usr/sbin/spamd line 240.
BEGIN failed--compilation aborted at /usr/sbin/spamd line 240.
So that was a bad idea and is not the answer. Looking at the resolv.conf manpage shows that the option indeed does different things which explains why that was wrong.
  inet6  Sets RES_USE_INET6 in _res.options.  This has the
		 effect of trying an AAAA query before an A query inside
		 the gethostbyname(3) function, and of mapping IPv4
		 responses in IPv6 "tunneled form" if no AAAA records
		 are found but an A record set exists.  Since glibc
		 2.25, this option is deprecated; applications should
		 use getaddrinfo(3), rather than gethostbyname(3).
So if I want perl programs to do what I want, I have to change every one of them to set $resolver->prefer_v6(1);. There is no sane default or a global "get into the 21st century" flag.

Changing /usr/share/perl5/Mail/SpamAssassin/DnsResolver.pm to include $res->prefer_v6(1); does help, but will need to be redone when updating spamassassin.

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2018-12-04 Really ending a domain name and the web presence 1 year ago
On 25 december 2004 there was a special deal giving me the .info names camp-wireless.info and campwireless.info for free for the first year. Since that moment I kept the names registered and redirected all web traffic to the right version: https://www.camp-wireless.org/. So the deal worked from a 'selling domain names' perspective: Christmas is a bad moment to review the need for domain names, so the easy solution is to renew it. My decision to stop with these names was made in January 2018.

Traffic to the .info versions is very minimal. With the cost of the domain registration I decided to stop doing that and devised an exit strategy which would result in a domain name that attracts no traffic and is not linked to my other webprojects. On the next renewal date the domain will expire. I have done this before in a different context: when we ended the students personal webspace at www.students.cs.uu.nl.

The solution is to start returing HTTP state 410 Gone for search engines while at the same time returning a somewhat user-friendly error page.

Relevant bit of apache 2.4 configuration:
<VirtualHost *:80>
    ServerName www.camp-wireless.info
    ServerAlias www.campwireless.info
    ServerAlias camp-wireless.info
    ServerAlias campwireless.info

	DocumentRoot /home/httpd/campwireless-expire/html

    <Directory "/home/httpd/campwireless-expire/html">
        Require all granted
    </Directory>

    RewriteEngine On
    RedirectMatch 410 ^/(?!gone.html|robots.txt)
    ErrorDocument 410 /gone.html
</VirtualHost>
The gone page is simple: It has an explanation for human visitors and a meta refresh tag to redirect the browser eventually. But to a search engine the status 410 on almost any url will give a clear flag the page is gone and should be flushed from the cache.
Read the rest of Really ending a domain name and the web presence

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2018-12-03 Being active in amateur radio at a strange time on a strange band: new country 1 year ago
Today I had a day off to arrange some stuff and found some time for amateur radio. I decided to put the longwire antenna outside and use the tuner to get on different bands than the standard 10/20/40.

So I was active at a strange time (during a working day) on a band I haven't been active on in months. Soon I saw signals from C5YK who is in The Gambia. After several tries I made the contact and had a new country in the log.

I also tried a lot of times to contact a station from Rodrigues Island but they never heard me.

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, reachable as koos+website@idefix.net. PGP encrypted e-mail preferred.

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