today's howtos
-
DNSSEC with NLnetLabs' LDNS and NSD
NLnet Labs make DNS software (and more), and amongst their best-known utilities are probably the recursive Unbound server and the authoritative NSD server, one which was originally written to drive a root DNS server.
I’m occasionally asked whether NSD can be used to serve a DNSSEC-signed zone (the answer is ‘yes’), but NSD isn’t a signer: it requires other utilities to actually sign zones which it can then serve. I’ve occasionally mentioned ldns, specifically when I wrote about using a SmartCard-HSM for DNSSEC and again when I wrote about DNSSEC signing with an offline KSK.
But let’s look at the task of signing one or more zones and serving them with NLnet Labs programs.
-
The Research Begins
I am noticing that nearly all of mail I get physically delivered I did not request, want or need. I want to collect all my mail for a month, classify it and organize it in order to figure out just how much junk I get. As part of that I want to identify all the types of mail and figure out if I was somehow responsible indirectly for obtaining it.
Now while collecting evidence for this future blog - I realized that mail this close to voting day will probably skew my stats. So I'll collect mail for the entire month of October, November and December and use that for a post.
-
Day 31: logical border properties
Just like for margin or padding, there are also logical property variations for border properties.
Originally there were 4 shorthand properties we could use for defining borders.
-
An email's Message-ID header isn't a good spam signal (in late 2022)
The good news is that Exim actually already logs the Message-ID value for every message in the 'id=' field logged as part of message reception logging. It was still more convenient to add my own logging that called out some specific aspects, but Exim's normal logging meant that I could already do some useful things with our historical data.
The bad news is that it turns out that the Message-ID header isn't a strong signal about whether or not the email was spam, and as part of that GMail is not being entirely honest in their SMTP time rejection messages. In the time when we were doing detailed logging, I saw a reasonable amount of real, desirable email without a Message-ID header at all (including a message to me), and some amount of it with what looked like 'invalid' Message-ID values. There's clearly some real mail sending systems that just don't put in a Message-ID.