Secondary Servers and DNS Replicas

The domain name system (DNS) is based on a hierarchical structure in which millions of servers around the world have part of the information needed for the Internet to function.

CSUC contributes to improving security and availability by maintaining replicas and secondary servers of different domains.

Secondary Servers and Replicas

Initially there were 13 root servers in the world, all the same among them. Of these, ten were in the United States, two in Europe, and one in Japan. The small number of root servers and the high concentration in the United States led some of the managers of these servers to consider having replicas in various strategic locations.

Replicas distributed around the world improve the security and availability of this essential service for the network operation. When DNS does not work or its access is degraded, applications as common as the web or social networks access become unusable or penalized.

At CSUC we maintain secondary and replicas of root servers and Top-Level Domains (TLDs).

• Replica of .cat domain: we have the Top Level Domain (TLD) .cat replica, since its creation in 2005. This replica contains information about all name servers that resolve domains under the .cat domain and sends the information to the rest of secondary servers in this domain.
• Replicas at CATNIX neutral point: At the Catalonia Internet Neutral Point (CATNIX) we have replicas of the root server named F, the root servers J, K and L, and the .com and .net TLDs. In addition, through some members of the neutral point, you can access other root server replicas and hundreds of TLDs from around the world.

These replicas increase service quality by improving response time for DNS queries, as well as increasing security, as it guarantees service in case of distributed denial of service (DDoS) attacks.

Secondary of the Anella Científica Institutions Domains

We offer the possibility of maintaining replicas of all the domains of the institutions of the Anella Científica.

That is because we are secondary to your institution's domain, all you have to do is set up your servers correctly and fill out the DNS Zone Secondary Request Form.

Reverse Zones of the Anella Científica Addresses

The Internet uses a special domain (.in-addr.arpa) to translate from IP addresses to names, as opposed to other domains, which translate from names to IP.

It works to ensure the correspondence of IP addresses to names and is used to increase security, for example in checking the reliability of mail servers.

It is highly recommended that any institution with a range of IP addresses assigned from the Anella Científica request the delegation of its reverse.

In addition, from the CSUC we will be secondary to these reverses.

Configure the server to resolve your inverses!

Primary of the Anella Científica Institutions Domains

Oferim la possibilitat d'allotjar les teves zones en els nostres servidors primaris de DNS en un entorn d'alta disponibilitat al cor de l'Anella Científica.

We offer the ability to host your zones on our primary DNS servers in a high availability environment in the heart of the Anella Científica.

DNS Resolvers

We offer two DNS servers to connected institucions at the Anella Científica. To provide redundant hosting, each of these two servers is located in one of the two CSUC's nodes, and its internet access is diversified. In that way, one goes through CSUC-CN and the other through CSUC-T. The address of Campus Nord server is 84.88.84.88 (dns.anella.csuc.cat) and uses RedIRIS connection, whereas CSUC-T server address is 84.89.1.10 (dns2.anella.csuc.cat) and accesses to Internet via Orange.