John R Pierce wrote:
> Agnello George wrote:
>> Hi
>> I have small query, all our server are centos based 5 and 5.2 . We are
>> looking ofr a tool to that measure packet loss. we have servers in two
>> IDC's bothin the US and we are trying to download a 2gb file from
>> the internet. Some server are able to download the file at a higher
>> b/w rate in one IDC ...while servers at he the other IDC download
>> the same file at a lowe b/w rate . Is ther any tool to measure packet
>> losses.
>
>
> # netstat -s
> ......
> Tcp:
> 4192230 active connections openings
> 12120496 passive connection openings
> 117185 failed connection attempts
> 129707 connection resets received
> 69 connections established
> 980405402 segments received
> 1087064944 segments send out
> 1572505 segments retransmited
> 11611 bad segments received.
> 91074 resets sent
> .....
>
>
> (the ..... are because it shows a lot more stats than just tcp). your
> 'dropped packets' are represented by 'segments retransmitted'.
>
> the only other way to measure dropped packets is to send test packets
> like via the PING command, and measure the responses. this, of
> course, can interfere with your normal traffic if the links are near
> saturated.
Or you can use wireshark to capture and decode a session (set a filter
on the target host address) and it will show the timing and
retransmitted packets.
--
Les Mikesell
lesmikesell at gmail.com