Am 13.10.21 09:58 schrieb Peter J. Philipp: > On Wed, Oct 13, 2021 at 08:02:35AM +0200, Michael Hekeler wrote: > > Hello list, > > > > I have question regarding network/routing. However it is not directly > > openbsd related (I can see the same even on windows machines) I decided > > to ask here because I know that there are many experienced admins here > > and there is wealth of expertise on such things on this list. > > > > On my site there are about 10 clients which connects to an internet > > database host. > > From time to time connection gets lost and sometimes the clients > > reconnect after a while but sometimes the database app breaks. > > > > When doing network diagnostics with mtr(8) which combines the > > functionality of traceroute(8) and ping(8) it shows the packets hopping > > through 8 to 9 hosts to reach the destination. > > When running this tool for a few hours it shows that two hosts in this > > route produces packet loss (~20%). > > > > My Question: > > is there anything I can do about that by myself or is only option to > > contact the admin of these hosts and hope that they are willing to fix > > whatever problem there is? > > If you have 9 hops and the packet loss is on hop 4 and 5 but does not carry > over to the destination you can ignore it. If it carries over to the > destination ie. hops 6, 7, 8 and 9, then you should look further at reaching > out. > > The reason is as follows: some routers pass packets through their ASIC's for > forwarding and it doesn't touch their processor at all, it's like offloading > the entire packet forwarding process. Yet when you talk to the IP of the > router directly, which is what ping does then the processor in the router > processes the packet and this may cause packet loss becuase usually they don't > have a fast cpu here. And ICMP doesn't have much priority in this case > either. > > Best regards, > -peter >
That's very interesting. Thank you so much. According to the DB hoster the loss showing at traceroute's output on hop 4 and 5 of 9 would provide reliable proof that the connection is the culprit. Now I understand that this conclusion is not automatically true. Hops 6,7,8,9 showed no more than 1% loss.
