Hi Keith, On Tue, Apr 13, 2021 at 11:10:18AM +0100, Keith A. Milner wrote:
However, if I change to using Kernel GTP, by changing the gtpu-mode to "kernel-gtp", traffic will not route (and, yes, I have done modprobe gtp). After some exploration, it appears the tun device is being created with an MTU of zero which then, cannot pass traffic:
I think this one is fixed in https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/dr... but "of course" Debian 10 is using a too old kernel to contain that fix. You could ask Debian if they'd back-port it to the stable kernel? We would certainly also be happy to accept a patch mentioning this in the user manual, or a patch that makes osmo-ggsn check the MTU at startup time and print some big error message into the log. -- - Harald Welte <laforge@osmocom.org> http://laforge.gnumonks.org/ ============================================================================ "Privacy in residential applications is a desirable marketing option." (ETSI EN 300 175-7 Ch. A6)