[CentOS] tcpdump loses lots of packets

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

Hello,

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
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> https://lists.centos.org/mailman/listinfo/centos
>


-- 
Stephen Clark
*NetWolves Managed Services, LLC.*
Director of Technology
Phone: 813-579-3200
Fax: 813-882-0209
Email: steve.clark at netwolves.com
http://www.netwolves.com