Re: Silently dropped UDP packets on kernel 4.14

Hi Michal, Thanks for providing a nice summary of your experience when dealing with this problem. Always nice to know that I am not alone :) On Thu, May 3, 2018 at 11:42 AM, Michal Kubecek wrote: > One of the ideas I had was this: > > - keep also unconfirmed conntracks in

Re: Silently dropped UDP packets on kernel 4.14

On Thu, May 03, 2018 at 07:03:45AM +0200, Florian Westphal wrote: > Kristian Evensen wrote: > > I went for the early-insert approached and have patched > > I'm sorry for suggesting that. > > It doesn't work, because of NAT. > NAT rewrites packet content and changes

Re: Silently dropped UDP packets on kernel 4.14

Hi Florian, On Thu, May 3, 2018 at 7:03 AM, Florian Westphal wrote: > I'm sorry for suggesting that. > > It doesn't work, because of NAT. > NAT rewrites packet content and changes the reply tuple, but the tuples > determine the hash insertion location. > > I don't know how to

Re: Silently dropped UDP packets on kernel 4.14

Kristian Evensen wrote: > I went for the early-insert approached and have patched I'm sorry for suggesting that. It doesn't work, because of NAT. NAT rewrites packet content and changes the reply tuple, but the tuples determine the hash insertion location. I don't

Re: Silently dropped UDP packets on kernel 4.14

Hello, On Wed, May 2, 2018 at 12:42 AM, Kristian Evensen wrote: > My knowledge of the conntrack/nat subsystem is not that great, and I > don't know the implications of what I am about to suggest. However, > considering that the two packets represent the same flow,

Re: Silently dropped UDP packets on kernel 4.14

Hi, Thanks for your quick and detailed reply! On Wed, May 2, 2018 at 12:24 AM, Florian Westphal wrote: > I'm not sure what the best way to solve this is, we either need > to insert earlier in nfqueue case, or do conflict resolution in nfqueue > case (and perhaps also nat undo?

Re: Silently dropped UDP packets on kernel 4.14

Kristian Evensen wrote: > On Tue, May 1, 2018 at 8:50 PM, Kristian Evensen > wrote: > > Does anyone have any idea of what could be wrong, where I should look > > or other things I can try? I tried to space the requests out a bit in > > time

Re: Silently dropped UDP packets on kernel 4.14

On Tue, May 1, 2018 at 8:50 PM, Kristian Evensen wrote: > Does anyone have any idea of what could be wrong, where I should look > or other things I can try? I tried to space the requests out a bit in > time (I inserted a sleep 1 between them), and then the problem went

Silently dropped UDP packets on kernel 4.14

Hello, I am currently debugging an issue where it looks like UDP packets are silently dropped. My setup is a client with a tool that sends two UDP packets (DNS requests) "simultaneously" using the same socket, and then a router running latest OpenWRT (with kernel 4.14.37). What I am seeing is