Wireshark 101: TCP Retransmissions and Duplicates, HakTip 133

[@pete-do3fz]

Good view of transmissions on ipad . Easy to see . Thank you.

[@InXLsisDeo]

This is good stuff, and I don't think you get this kind of technical details elsewhere on KZbin. Love it. Sometimes, it can help if you use KZbin annotations.

[@PSzlazak]

All stuff visible in square brackets in Wireshark, are Wireshark calculated items. It's not data in packet.

[@carfokf1995]

Thanks for that video, now i can clearly understand my activity.

[@08Billmr]

So, in order to see if a packet is indeed re transmitted I have to check if it didn't get the acknowledgment ? So every packet after the first acknowledgment = 0 with the same sequence number is the retransmitted packet?

[@areyounotentertained9499]

lol "And alot of stuff I just skipped over" hahaha classic!

[@VinnuKannnu]

Need to add sack topic is must when explaining dup ack ?

[@iarde3422]

I was trying to find the information about how to find those retransmissions and I didn't find it in this video.

[@sandeep9shukla]

Beauty with Brain really amazing video, Nice keep up the good job

[@networks24x73]

Tharki spotted

[@rodrigomunoz1556]

Este video merece más views

[@rondlh20]

OK, cool, that's clear. Now how to make use of this to increase network traffic? I don't thinks the RTO should increase after every loss. Actually I know the response time of my target machine quite well, if it doesn't respond within a fixed time plus a little bit of margin, then I know the packet was lost and I would like to resend it asap. Is there any way to control this?

[@ojammeh]

hi i have this retransmission problem. how do i solve it?

[@axeltroja9390]

Is there filter expression so that I just see those packages, so that I can watch out for outdated clients who try to connect to something that doesn't exist any more

[@ccu337]

+Axel Troja : tcp.analysis.retransmission shows only the retransmissions. There are several other useful tcp.analysis filters that you can use to find other issues (e.g. out of order, duplicates, etc.)

[@ccu337]

Here's the documentation page on tcp filters: www.wireshark.org/docs/dfref/t/tcp.html

[@pauliewalnuts6734]

great video!!

[@SantoshSharma]

Nice video. Could you please. Explain Retransmission with bad checksum

[@RogerBarraud]

NO link to "Practical Packet Analysis?" :'(

[@Slap_it_in]

Ok how do you fix them :)

[@renanangelodossantos4726]

it's common to americans say, for example, eight-o-six instead of eigth-zero-six?

[@networkfreddy2000]

Mericuh!

[@nitinahuja2472]

What's the RTO of 1st TCP SYN?

[@claay832]

This has happened to me last year. RTO of the 1st SYN is 3.0 secs. Then the 2nd RTO double to 6.0 secs .. Then 3rd RTO is 12 secs then 24 secs .. Then 48 secs for the 5th RTO. If no SYN-ACK was received by the initiating host, then it will send a TCP RST flag to close reset the connection. Then it will start the process all over again until such time that it receives a SYN-ACK.

[@georgemavimbela]

thank u som uch this is good

[@KowboyUSA]

TCP RTO, ahh I C.

[@RicardoHernandez-zr1pw]

Ok, but how do you fix these type of issues ?

[@stoneddeer8646]

Thats up to you and only you would know. You have a pcap. That moves your case forward in that direction toward a solution. Shes not going to tell you how to fix whatever scenario you are in within your own context.

[@networkfreddy2000]

THANK YOU!...but how to i resolve the issue lol

[@marcelino2002]

fiquei até o final do vídeo esperando por isso tbm kkkkk

[@mwebazemoses]

thats cool

[@BossManTee]

or SR