Why DNS Works On Both TCP and UDP - TechGenix
Feb 18, 2018 · By the end of this course, you’ll be able to: - describe computer networks in terms of a five-layer model. - understand all of the standard protocols involved with TCP/IP communications. - grasp TCP/IP - Transport Control Protocol/Internet Protocol. A set of rules for communication between computers where each device (host) is assigned a unique IP address which is valid on a particular network. An IP address is made up of 4 "octets" ranging between 0 and 255, and separated by a period or dot. (Ex. 220.127.116.11) DNS uses TCP when the size of the request or the response is greater than a single packet such as with responses that have many records or many IPv6 responses or most DNSSEC responses. The maximum size was originally 512 bytes but there is an extension to the DNS protocol that allows clients to indicate that they can handle UDP responses of up For UDP, with a typical IPv4 header length of 20 bytes and a UDP header length of 8 bytes, that's 1472 bytes of data, so it's probably good enough to use TCP rather than UDP for DNS messages larger than 1472 bytes (IP fragmentation and reassembly will happen if any hop in the network route can't handle a 1500-byte IPv4 packet; that does TCP et UDP sont les deux protocoles principaux de la couche transport. Lors de la configuration d'un routeur ou d'une box internet, il n'est pas rare d'avoir à choisir entre les ports TCP et les DNS is a great example of an application layer service that uses UDP for the transport layer instead of TCP. This can be broken down into a few simple reasons. Remember that the biggest difference between TCP and UDP is that UDP is connectionless. This means there is no setup or teardown of a connection.
UDP vs TCP - Which One Is The Best? - BitTorrentVPN
TCP port 53 can be used in the cases where the DNS responses greater than 512 bytes. However, using UDP messages are preferable to using TCP for large DNS messages is due to the fact that TCP
Why is UDP used for DNS instead of TCP? Isn't TCP supposed
RFC 7766 DNS over TCP March 2016 1.Introduction Most DNS  transactions take place over UDP .TCP  is always used for full zone transfers (using AXFR) and is often used for messages whose sizes exceed the DNS protocol's original 512-byte limit.The growing deployment of DNS Security (DNSSEC) and IPv6 has increased response sizes and therefore the use of TCP. Pourquoi DNS utilise-t-il UDP au lieu de TCP? [Résolu DNS n'est pas un protocole de transmision et DNS n'utilise pas UDP ou TCP. DNS permet a des protocoles UDP ou TCP d'utiliser DNS ou si tu prefere UDP ou TCP passent au travers d'une DNS qui n'est autre qu'une resolution de nom de domaine et non pas une couche de transmission de protocole. Du reste des paquets de type ARP par exemples sont Preparing for DNSSEC: Best Practices, Recommendations, and DNS can use either the User Datagram Protocol (UDP) or Transmission Control Protocol (TCP); historically, it uses a destination port of 53. When the DNS protocol uses UDP as the transport, it has the ability to deal with UDP retransmission and sequencing. DNS - TCP or UDP