A simple tutorial to help configuring your DNS on the Jaguar Network extranet
Here are the theoretical notions to know to manage your DNS.
A domain name is a « mask » on an IP address.
The purpose of a domain name is to easily remember and communicate the address of a set of servers (web site, email, FTP…).
For example, www.jaguar-network.com is simpler to memorize than 220.127.116.11.
A domain name can be purchased from a registrar for a time period. So it needs to be renewed when it expires.
When you want to visit a web site, a conversion is operated between the website name and its IP address via the DNS server of your operator as in the following example :
Access attempts to the website : http://www.jaguar-network.com via a customer browser.
The request is sent to the DNS server configured on the post.
If there already is the cached IP matching this name, it immediately answers to the customer. If it does not know it, it will query the roots servers to know who has the configuration of this domain name
The research is operated for the “.”, “com.”, “jaguar-network.com.” zone
During the request “who manages the jaguar-network.com zone ?”, the DNS server will answer : ns1.as30781.net et ns2.as30781.net.
This DNS is also questioned : “What is the www.jaguar-network.com IP ?”
The found IP is sent back to the DNS server of your access provider that cache this IP and sends you 18.104.22.168.
The website http://www.jaguar-network.com/ displays on your computer.
Here is the list of the DNS entries most frequently used.
record or address record that matches a hostname to an IPv4 address of 32 bits distributed on four octets ex: 22.214.171.124.
record or IPv6 address record that matches a hostname to an IPv4 address of 128 bits distributed on sixteen octets.
record or canonical name record that allows to make from a domain, an alias to another. This alias inherits all the original’s subdomains.
record or mail exchange record that specifies the mail servers for this domain ;
record or pointer record that associates an IP address to a recording of domain name, also said « reverse » since it is doing the exact opposite of the A record.
record or name server record that specifies the DNS servers of this domain.
record or Start Of Authority record gives general information about the zone : main server, contact e-mail, different periods including expiration, sequence number of the zone.
record that generalizes the MX record notion, but also proposes advanced features such as the load-balancing quota for a particular service, standardized in the RFC 2782.
record or Name Authority Pointer record gives access to information rewriting rules, allowing matches loose enough between a domain name and a ressource. It is specified in the RFC 3403.
record allows an administrator to enter any text in a DNS recording (for example, this recoding was used to implement the Sender Policy Framework specification).
Each DNS entry needs a name, a type, an address and a TTL.
TTL (time to live) is the time to live of a domain name.
This 32 bits field integrates a default unit of seconds 86400 so 24h
The TTL describes how long the domain name is cached before being « forsook » by your FAI DNS.
In the spread, TTL is the refresh time of the recording you are going to create.
Due to performance reasons of the DNS servers, you need to avoid putting a weak TTL if it is not necessary.
A 86400 TTL is more than enough in most cases.
First of all, it is essential to be the owner of a domain name, which you can purchase from a registrar, where you would change the DNS type entries to point them to the Jaguar Network servers :
After a propagation delay (from few minutes to 24h, tops), any request conducted over the internet to question a domain (How a ping, dig, nslookup etc.) will be directed towards the Jaguar servers, which will answer with the information provided
Into image, here is the proceeding to create a DNS entry :
Identify on https://extranet.jaguar-network.com and access to My DNS management
Create a now zone and enter the domain name.
Choose to Create a now zone (or Copy an existing zone and select the zone to copy, if you already have a pre-informed zone) and click on Create the zone.
By default, the mail (MX) and www (A) entries already exist, all you have to do is changing the servers IP addresses respectively issuing the email and web services
To create a new entry, click on Add an entry and enter the entry name, the type, the IP address of the entry target and a TTL (86000 by default)
The modifications are taken into account every 4 hours (00-04-08-12-16-20).