Wireshark-users: Re: [Wireshark-users] 8-10% packet error/loss is normal wired network?
From: Flako <[email protected]>
Date: Tue, 10 Jul 2012 12:32:12 -0300
Hello Jim
Counting only "tcp.analysis.retransmission" I'm from 0.95% to 1.21%, a value more enjoyable. :)

I think it's despicable for further research .. but I get the question if this value is normal :)
In a wireless link, a loss of 1% is acceptable, but in a network cableda?

Something strange I have in the network, because making you ping ip of the printer, lost packets (8 of 10 330). A value despreciale but should not happen.

2012/7/10 [email protected] <[email protected]>
No, 8 to 10% is not normal, but your display filter is grossly over-counting the packet loss. To start with, by showing both the packet with the "previous segment lost" message and also the retransmission, you're counting each lost packet twice. And then, a single lost packet requires at least three duplicate ACKs before a fast retransmission is generated.

Try filtering on retransmissions only. This will give you a more accurate count of lost packets. By the way, tcp.analysis.retransmission includes fast retransmissions, so you don't have to include tcp.analysis.fast_retransmission as a separate display filter condition.

----- Reply message -----
From: "Flako" <[email protected]>
To: <[email protected]>
Subject: [Wireshark-users] 8-10% packet error/loss is normal wired network?
Date: Tue, Jul 10, 2012 6:04 AM

     I am analyzing the network with wireshark :) and found 8-10% of lost packets (filter: malformed | | tcp.analysis.lost_segment | | tcp.analysis.retransmission | | tcp.analysis.fast_retransmission | | tcp.analysis.duplicate_ack ) between various Linux desktop and an HP 2420n (network printer)

     The printer is connected to switch A (100Mbit) and dektop are connected to the switch B (1Gbit), where A and B swich are interconnected.
     The printer was replaced (otherwise error) and the new printer keeps happening the same.
     I can only see wiring issues.

     On if my question is if this% is "normal" (hard word) in a wired network scheme (it seems to me much)
     Is there any way to look at something else, to know that it also occurs to a statistic on the filter showing up?

   Thanks for reading. and sorry for using google translate.

Sent via:    Wireshark-users mailing list <[email protected]>
Archives:    http://www.wireshark.org/lists/wireshark-users
Unsubscribe: https://wireshark.org/mailman/options/wireshark-users
             mailto:[email protected]?subject=unsubscribe