Question about OsmoGGSN project

Pau Espin Pedrol pespin at
Mon Feb 8 09:35:02 UTC 2021


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", 

Hope this is useful to you,

- 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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