[CentOS] tcpdump loses lots of packets

Mon Aug 15 12:36:09 UTC 2016
Steve Clark <steve.clark at netwolves.com>


I've found it is helpful to limit the length of the packet you are capturing by using
something like -s 256.

On 08/14/2016 06:04 PM, Anand Buddhdev wrote:
> On 14/08/16 12:20, Anand Buddhdev wrote:
> Hi folks,
> I've discovered something. See below:
>> The packet rate is also not that high. From the sending side, this is
>> what I have:
>> # tcpreplay -i qtx:p1p1 5min.pcap
> If I send packets without qtx, like this:
> tcpreplay -i p1p1 5min.pcap
> then tcpdump on the receiving box has no problem, and keeps up happily
> with the queries, and receives all of them into the pcap file. It seems
> like the qtx module is somehow interfering with the packet capture, but
> I don't know how or why yet.
> Anyway, for low packet rates, such as 20,000 q/s, qtx isn't necessary,
> so I will not use it when I want to do packet captures.
> Regards,
> Anand
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Stephen Clark
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