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How UDP handle duplicate packets?
The possibility to receive duplicate UDP packets in destination host depends on number of destination interfaces that receives the packet from the source host. The destination will receive three duplicate UDP packets if three of its interfaces(eth1, eth2, eth_int) can fetch the packets from source at same time.
What is a duplicate packet?
Duplicate packets are packets that are captured twice or multiple times by Observer. Typically, duplicates are a result of how data is sent to Observer . For a switch, the use of a SPAN/mirror port and/or trunk is required to capture data.
Why is IP protocol is considered unreliable?
IP is a unreliable protocol because it does not guarantee the delivery of a datagram to its destination. The reliability must be provided by the upper layer protocols like TCP. IP does not support flow control, retransmission, acknowledgement and error recovery.
Why does UDP exist Would it not have been enough to just let user processes send raw IP packets?
14. Why does UDP exist? By using UDP, a segment will be delivered correctly to the specified application because UDP uses source and destination ports while raw IP packet does not include ports. That is, a segment cannot be delivered to a specified application as a raw IP packet.
Which is a reliable protocol?
Together, Transmission Control Protocol (TCP) and IP provide a reliable service, whereas User Datagram Protocol (UDP) and IP provide an unreliable one.
What does it mean when a packet is duplicated?
Duplicate Packets Duplicate packets are an often observed network behaviour. A packet is duplicated somewhere on the network and received twice at the receiving host. It is very often not desireable to get these duplicates, as the receiving application might think that’s “fresh” data (which it isn’t).
Can a connectionlessprotocol detect a duplicate packet?
ConnectionlessProtocols such as UDP won’t detect duplicate packets, because there’s no information in, for example, the UDP header to identify a packet so that packets can be recognized as duplicates.
When is it not desireable to get duplicates?
It is very often not desireable to get these duplicates, as the receiving application might think that’s “fresh” data (which it isn’t). If a sending host thinks a packet is not transmitted correctly because of a PacketLoss, it might Retransmit that packet.
Is there a way to detect duplicates in Wireshark?
The data from that packet will be indicated twice (or even more) to the application; it’s the responsibility of the application to detect duplicates (perhaps by supplying enough information in its headers to do so) and process them appropriately, if necessary.