I forgot to mentioned, just to be clear, these IFs are all one node, the same one hos, its routing table: 10.5.6.0 0.0.0.0 255.255.255.0 U 350 0 0 nm-team1 172.25.12.0 0.0.0.0 255.255.255.0 U 100 0 0 p3p3 192.168.2.0 0.0.0.0 255.255.255.0 U 110 0 0 em2 192.168.2.0 0.0.0.0 255.255.255.0 U 111 0 0 em1 no default gateways, so you can see these are directly connected networks $ traceroute -n 10.5.6.17 -i em1 traceroute to 10.5.6.17 (10.5.6.17), 30 hops max, 60 byte packets 1 10.5.6.17 0.426 ms !X 0.393 ms !X 0.311 ms !X $ traceroute -n 10.5.6.17 -i em2 traceroute to 10.5.6.17 (10.5.6.17), 30 hops max, 60 byte packets 1 10.5.6.17 0.382 ms !X 0.326 ms !X 0.274 ms !X $ traceroute -n 10.5.6.17 -i nm-team1 traceroute to 10.5.6.17 (10.5.6.17), 30 hops max, 60 byte packets 1 10.5.6.17 0.407 ms !X 0.342 ms !X 0.294 ms !X $ traceroute -n 10.5.6.17 -i p3p3 traceroute to 10.5.6.17 (10.5.6.17), 30 hops max, 60 byte packets 1 * * * 2 * * * 3 * * * 4 * * * I was expecting kernel's network would know best, what to do, especially that: (enp6s0f0 is 10.5.6.17) root at 10.5.6.17 ]$ ping 172.25.12.222 -I enp6s0f0 PING 172.25.12.202 (172.25.12.222) from 10.5.6.17 enp6s0f0: 56(84) bytes of data. 64 bytes from 172.25.12.222: icmp_seq=1 ttl=64 time=0.396 ms there are two switches and vlans, switches routes auto configured, no default gateways on the switches neither, to try to simplify & troubleshoot. regards L. On 16/08/16 11:59, John R Pierce wrote: > On 8/16/2016 3:53 AM, lejeczek wrote: >> >> $ ping 10.5.6.17 -I p3p3 >> PING 10.5.6.17 (10.5.6.17) from 172.25.12.202 p3p3: >> 56(84) bytes of data. >> >> and nothing, ping waits and no reply, Ctrl+C >> >> with such a simple setup rules based routing should not >> be involved, kernel should figure it out, right? > > you specifically said to send that packet to an interface > on the wrong network, of course, its not going to get > through, unless there's an external route from that > network to the destination. I'm presuming there's a router > somewhere else between your 192.168.2.0/24 network and > 10.5.6.17, that would enable those ping -I em1/2 commands > to work. note that the recipient of the ping needs to > have a route to get back to the source, too. > > > >