Saturday, 5th October 2024

Local IP addresses in public DNS and OpenWRT rebind protection, fix address resolution First of all, I have noticed that I cannot resolve private IP addresses (RFC1918) defined in my CloudFlare DNS zone. While on the network served by OpenWRT router, I got this error: $ nslookup ****.prokop.dev *** No internal type for both IPv4 and IPv6 Addresses (A+AAAA) records available for zt33.prokop.dev Server: OpenWrt.lan Address: fd**:****:****::1 And it of course works when using network in my Belfast’s home office, which is currently served by EdgeRouter 4 (to be soon replaced by custome OpenWRT built on RPi5)....

October 5, 2024 · 4 min · Bart Prokop

Email security with Google Workspace

TL;DR; What records needs to be added to DNS? v=spf1 include:_spf.google.com -all v=DKIM1; k=rsa; p=MIIBI...6lwIDAQAB google._domainkey v=DMARC1; p=reject; rua=mailto:[email protected] default._bimi v=BIMI1; l=https://fizjoterapia.uk/bimi.svg SPF Sender Policy Framework (SPF) is an email authentication method which ensures the sending mail server is authorized to originate mail from the email sender’s domain. It is absolutely necessary to have SPF entry in DNS zone - otherwise your email will end-up in SPAM folder or even will be discarded....

July 23, 2023 · 5 min · Bart Prokop

WKD setup for your domain

I have recently tried and was keen to see that Proton Mail supports WKD. $ gpg --locate-key [email protected] gpg: key 4DE32C2A10A7EBC2: public key "[email protected] <[email protected]>" imported gpg: Total number processed: 1 gpg: imported: 1 pub ed25519 2021-10-13 [SC] 67731B189D0908618DF665144DE32C2A10A7EBC2 uid [ unknown] [email protected] <[email protected]> sub cv25519 2021-10-13 [E] So here is quick instruction how to setup WKD for any email (i.e. not hosted by Proton Mail). First you need to create empty file relative to your webserver ROOT....

June 13, 2022 · 2 min · Bart Prokop