Add IP and domain description

diff --git a/docs/README.md b/docs/README.md
index 7126e3aea0b9d9fb472a98f3573cd9568a10f84c..97cbc9262628fd1210992e4b7b0b9243106d5aef 100644 (file)
--- a/docs/README.md
+++ b/docs/README.md
@@ -25,10 +25,22 @@ I am using a Linux distribution with a rolling release. Continues updates keeps
 A Soldam Alcadia ZR300 Black Knight Casing I bought in Japan 2009. It can fit an extended-ATX motherboard inside and plenty of hard drives. I do not need any tools to it open since the screws can be removed by hand.
 ![High-tower](./img/windy.jpg)
 
+Of course a cabinet alone does not make a server. But I will not go into details with the content of the cabinet. It is pretty standard components. The components in the server are of older type. The server gets upgraded with recycled components from other desktop computers in my house, when they get upgraded with new components.
 
-### Fixed IP address and domain name
+### Fixed IP address, domain name and DNS
+In order to setup a personal mail server a fixed IP address and domain name is needed. I got a fiber connection to my house from the local ISP [Eniig fiber](https://eniig.dk). It was installed soon after I moved into my house. A fitting domain name was found at [dk-hostmaster](https://www.dk-hostmaster.dk) and ordered. 
 
+I decided to store my DNS settings at [Cloudflare](https://cloudflare.com). In order to get a secure connection to my server I had to setup many DNS records
 
+* A record for zndr.dk (@zndr.dk)
+* CNAME wildcard record for subdomains (*.zndr.dk)
+* A record for mail.zndr.dk
+* MX record mail.zndr.dk
+* CAA record for LetsEncrypt
+* TXT records for DMARC1, DKIM1 and SPF1
+* DS record for DNSSEC
+
+I had to call the ISP and ask them to setup a reverse DNS record for my mail server (mail.zndr.dk) which they did. At dk-hostmaster I could login myself to store Key and activate DNSSEC.
 
 ### Back up of data