Using the Fediverse to Add Comments to a Static Website
John Dickinson
Since I migrated this website to HUGO I have been searching for an elegant way to allow comments on our blog posts. I looked at most solutions given in the Hugo Documentation. They all seemed overly complex and involved third party services. So I started thinking if it would be possible to use statuses on Mastodon. It turns out I was not alone and this has been done before several times.
Happy 15th Birthday Sinodun!
John Dickinson
Today in 2010 we incorporated Sinodun Internet Technologies. It has been a fantastic 15 years with many exciting, enjoyable and interesting projects to work on. We would like to thank all of our customers who have supported us, and also all the grant awarding organisations that have funded our work over the years. It has been a pleasure and privilege to be part of the DNS and standards community …
New Website
John Dickinson
Welcome to our new website. As a side project over the last few months we have migrated from Wordpress to a static Hugo website. It is based on the hugo-bootstrap theme. Anecdotal evidence suggests it is much faster. We use no cookies or any kind of tracking and nothing about our users is recorded unless we need to troubleshoot a problem. See our privacy policy. Since this site is now static, we …
Wiki Js and Katex
I have been playing with Wiki.js, I happened to notice that some math was not getting rendered correctly. Wiki.js uses Katex to render Latex (like) math expressions. I wanted to produce an unordered list of equations like this,
\(\braket{v_i|v_i} = 1\) because we are dealing with a unit vector \(\braket{v_1|v_2}=\braket{v_2^*|v_1^*}\) \(\braket{v_1\vert(a\vert v_2}+b\ket{v_3})=a\braket{v_1\vert …
Working with Materialized View tables in ClickHouse
There must be something about January which makes John prod me into a blog post about something I’ve just teased out. So here we are, it’s 2020, it’s January, and what is fast (OK, not so fast) becoming an annual tradition.
Today’s post is a selection on snippets on Materialized Views. Materialized Views, if you haven’t met them, are tables automatically populated …
Junos DHCPv6 DNS Search List
I have been looking at the DHCPv6 server in JUNOS 15.1X49-D160.2. It is easy enough to setup Note: Step 5 is wrong, the first two instructions should have dhcpv6 as the last argument e.g.
set security zones security-zone untrust interfaces ge-0/0/0.0 host-inbound-traffic system-services dhcpv6 It would be nice to configure the DNS Search List option. The option code for this is 24. So I tried this …
Executable External Dictionaries in Clickhouse
External dictionaries, a dictionary populated by an external source, are a rather useful way to make data external to ClickHouse accessible when working in ClickHouse. One option for the source of the external data is an executable. I found, though, that the documentation doesn’t clearly tell you how to use this, so here I’m trying to rectify this.
There are two basic types of executable external …
Using OpenSSL from inside a chroot
A little something we tripped over this week. We’re providing an experimental DNS-over-TLS server that supports TLS v1.3. Right now TLS v1.3 is still an Internet Draft; in other words, it’s not a finished standard, though close to it. The latest version of the draft is draft 23, support for which was merged into the OpenSSL master branch yesterday, January 25th. Yup, we’re living on the bleeding …
More on Debian Jessie/Ubuntu Trusty packet capture woes
Back in September I wrote about a problem we’d come across when capturing traffic with pcap_dispatch() or pcap_next_ex() on Ubuntu Trusty or Debian Jessie. When the traffic was slow, we saw packets not being captured.
We’ve since done a bit more digging. The problem, we think, is a bug in the Linux kernel select() system call. With both pcap_dispatch() and pcap_next_ex() we’re using a central loop …
Compressing pcap files
Here at Sinodun Towers, we’re often dealing with pcap DNS traffic capture files created on a far distant server. These files need to be compressed, both to save space on the server, and also to speed transfer to our machines.
Traditionally we’ve used gzip for quick but basic compression, and xz when space was more important than CPU and we really needed the best compression we could get. At a …
Packet capture woes with libpcap on Ubuntu Trusty and Debian Jessie
Usually when you’re using libpcap to capture network traffic, your chief worry will be whether or not your application will keep up with the flow of traffic.
Today, though, I’ve stubbed my toe on a problem with traffic that’s too slow. It happens with both Ubuntu Trusty and Debian Jessie. If there’s a gap between packets of more than about 50 milliseconds, the first packet to arrive after the gap …
Juniper SRX mucking with DNS
I was getting some strange DNS answers on the servers in a trust zone on my SRX. All the servers are statically NAT’d to external IP’s and run their own caching resolvers but when I tried to query for the servers A RR I kept getting the internal IP address. No name server either internal or external was serving that A RR. Eventually I realised that it was the SRX changing the answer section of the …