Question about OsmoGGSN project

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morteza ali Ahmadi morteza.ali.ahmadi at
Mon Feb 8 21:05:26 UTC 2021

Thanks Pau, I'll check it out and share my results with you.

On Mon, Feb 8, 2021 at 1:05 PM Pau Espin Pedrol <pespin at> wrote:

> Hi,
> you are probably facing a routing issue, and you need to solve it by
> using different network namespaces (netns).
> In your current setup, you probably have routing for those DNS packets
> to go through the sgsnemu iface, and once the ggsn puts them again in
> the network stack after going through GTP, the kernel probably ends up
> dropping the packet because it finds out some sort of loop.
> In order to solve it, the easiest is to run sgsnemu under a different
> netns, and set default routing inside that netns to the tun iface
> created by sgsnemu. AFAIR, the netns can take care of creating the netns
> and configuring it for you, check it's man page ("--defaultroute",
> "--netns").
> Hope this is useful to you,
> Pau
> --
> - Pau Espin Pedrol <pespin at>
> =======================================================================
> * sysmocom - systems for mobile communications GmbH
> * Alt-Moabit 93
> * 10559 Berlin, Germany
> * Sitz / Registered office: Berlin, HRB 134158 B
> * Geschaeftsfuehrer / Managing Director: Harald Welte

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