When you browse the internet, you don’t write IP addresses to go to the pages you want; you just write the domain. In the “backstage”, every request that you do, passes through a DNS query. It first goes to your internet provider’s recursive DNS server. If it can’t find in the cache, the information needed, it will continue to other recursive servers until it gets to an authoritative DNS server who can give the IP address of the required domain. Basically, it is a name server, that is a middle-man between you, the user, and the authoritative DNS server.
Tasks of the recursive DNS server:
1. Checks if the IP address is stored in the cache memory. There is a certain period of time, pre-defined by the domain’s owner called Time to Live or TTL. It says for how long the recursive server can hold the information. If it is still there, it will return the answer fast and won’t take further actions.
2. Searches for the IP address elsewhere. If it is not in the cache, it will continue the searching process until it gets to an authoritative server which has the information.
Continue reading “What is a Recursive DNS server?”
DDoS Attacks are widespread threats on the internet. With the continually increasing numbers of connected devices and new innovative ways of hacking them, we can’t just stay and wait to get affected. We should smartly implement our DNS infrastructure and choose a trusted DNS provider to be safe and to evade the downtime of our services.
But to be protected, we must know the danger.
DDoS attack (denial-of-service attack). There are few different types, but in general, a DDoS attack is an attempt to overwhelm the target (a computer, few connected computers or a whole DNS network) with high traffic from multiple sources.
Continue reading “DDoS attacks and how to protect ourselves”
DNS is the backbone of the internet. It connects all the users to the content they need. It is a constant exchange of information, but sometimes the DNS fails and this cause downtime. A blackout period that can be evaded by using a backup DNS.
Backup DNS, also known as Secondary DNS or alternative DNS is a system of one or more DNS servers, who have a copy of the zone data (DNS records) of the Master (Primary) DNS server. It adds resilience, reduce the outage periods by answering requests even if the Master is down.
It is easy to set up, and it can save you tons of problems. If your Master DNS got damaged and lost the information, you would still have a copy in your Backup DNS.
What is the worst that can happen? Dyn DNS attack of 2016
Continue reading “What is backup DNS?”