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TCP - Why do RST packets not require acknowledgements (and FIN packets do)?

FIN tells the receiver of the FIN that the sender of the FIN is done sending data, but it will still listen. The receiver of a FIN is under no obligation to stop, unless it is also done, and it can ...
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2 votes

TCP - Why do RST packets not require acknowledgements (and FIN packets do)?

RST is a "mission abort" - waiting for an ACK (that's not unlikely to never come) isn't productive. In contrast, FIN is a completely normal message in the connection lifecycle, so it's ACKed....
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1 vote

GNS3 - hosted or VM?

The GNS3 VM distribution is an optimized Linux VM that comes already configured to optimally run the included GNS3 simulator. Using the VM, you save yourself the effort of tweaking your hosted ...
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For TCP, what is the justification that ACKs are Last Byte Received + 1 and not just Last Byte Received?

The sender knows the next segment number it will send, so when the receiver sends an ACK it sends an acknowledgement number of the next expected segment number. If the sender's next segment number is ...
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For TCP, what is the justification that ACKs are Last Byte Received + 1 and not just Last Byte Received?

Whether the receiver acknowledges the last received byte (I have received up to x) or the next expected byte (I have received everything before x) provides the exact same information. It's just a ...
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QOS operation doubt

QoS markings are typically set at the client machine or at the access switchport that the client plugs in to and every single IP packet that meets the criteria for a QoS marking get's the mark. TCP is ...
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1 vote

QOS operation doubt

Does QOS marking in the IP header occur on every packet or does it need TCP segmentation established (TCP handshake)? Depending on your devices and their configurations, you need to mark each packet'...
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2 votes
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QOS operation doubt

Example, I have a rule configured applying priority 1 to destination port 443, in the initial syn it already marks or would wait for the connection established. I understand that no, QOS is in the IP ...
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2 votes

How to benchmark time a packet spend in each OSI layer?

Your computer software, including the operating system, does not use the OSI model. So it’s impossible to measure. The models are just that—models. Real computers don’t follow it exactly. In addition, ...
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2 votes
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How to benchmark time a packet spend in each OSI layer?

I don't think focusing on the layers is really practical. While measuring the impact of external devices is fairly easy - just remove, reinsert and replace them from the measured path -, internal ...
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