Traceroute command and its options

Traceroute

Many network administrators use the traceroute command daily. It is a convenient tool that you can use under different operation systems – Windows (Tracert), MacOS, Linux (traceroute) and even on mobile (Android and iOS).

You can use traceroute, and see the full route that the packets take to their destination (domain or IP address). Apart from that, you will see the hostnames and IPs of the routers on the way and the latency, the time it takes for each device to receive and resend the data.

You can see which gateway is discarding your data and later you can fix it.

Traceroute

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Primary DNS server

We have already talked about what is DNS and what is a Secondary DNS, this time we will focus on the Primary DNS server. There is a DNS hierarchy in which the Primary DNS server is taking the central spot. It has the latest and full information, in comparison with lower level DNS servers who has just a cache of this information and with an expiry period.
Primary DNS

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Why does DNS use UDP?

There are various ways of sending data over IP – TCP, UDP, DCCP, SCTP, RSVP and more. We will focus our attention on the two that are most used – the UDP (User Datagram Protocol) and the TCP (Transmission Control Protocol).

UDP

UDP and TCP

Both protocols are used to send packets of data over the internet. They do that on top of the IP protocol, which means that they direct the packets to IP addresses. They are treated very similar on their way from the users’ computers, through the routers and all the way to the end destination.

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