Issue on capturing using DPDK Pdump on secondary interface.

Issue on capturing using DPDK Pdump on secondary interface.

[Navin Srinivas]

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Hello,

We are facing a strange issue, we have the following setup for our
application. We wanted to capture packets using dpdk pdump for our
application, and started to notice an issue in capturing on DPDK 21.11
So we went back to DPDK 20.11 and we still saw the issue.

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Think there is an issue in the pdump library to capture packets on the
secondary interface. But I'm not sure where to look.
APP1 - Primary APP
APP2 - Secondary APP.
Ports and ring inits are done by APP1 for APP2.

We are able to capture packets using the standard example application of
pdump and capture on port 0, but we are not able to capture on port1.

Has anyone come across this issue? Is there an open bug for this?
The multi process is working properly, and we are able to transmit and
receive packets on the secondary interface without any issue. We are facing
issue only on capturing packets on that interface(port1).

Are there any pointers where I can start to look?

Thanks & Regards,
Navin Srinivas

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Re: Issue on capturing using DPDK Pdump on secondary interface.

[Stephen Hemminger]

On Thu, 25 Aug 2022 11:43:11 +0530
Navin Srinivas <g.navinsrinivas@gmail.com> wrote:

> Hello,
> 
> We are facing a strange issue, we have the following setup for our
> application. We wanted to capture packets using dpdk pdump for our
> application, and started to notice an issue in capturing on DPDK 21.11
> So we went back to DPDK 20.11 and we still saw the issue.
> 
> [image: image.png]
> Think there is an issue in the pdump library to capture packets on the
> secondary interface. But I'm not sure where to look.
> APP1 - Primary APP
> APP2 - Secondary APP.
> Ports and ring inits are done by APP1 for APP2.
> 
> We are able to capture packets using the standard example application of
> pdump and capture on port 0, but we are not able to capture on port1.
> 
> Has anyone come across this issue? Is there an open bug for this?
> The multi process is working properly, and we are able to transmit and
> receive packets on the secondary interface without any issue. We are facing
> issue only on capturing packets on that interface(port1).
> 
> Are there any pointers where I can start to look?
> 
> Thanks & Regards,
> Navin Srinivas

Pdump is a secondary application itself.

Pdump doesn't handle multiple interfaces well, it puts everything
together.  You probably are better off using the new dumpcap which
supports pcapng. Pcapng supports multiple interfaces in single capture.