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
