On Mon, Jan 19, 2015 at 4:21 PM, Dave Tian <dave.jing.tian@xxxxxxxxx> wrote: > Check arp_* fields in > https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt > Thanks! This looks helpful. > -daveti > > > On Jan 19, 2015, at 7:11 PM, Mike Krinkin <krinkin.m.u@xxxxxxxxx> wrote: > > Hi, > > On Mon, Jan 19, 2015 at 03:42:58PM -0800, Mandeep Sandhu wrote: > > Hi All, > > Please let me know if this is not the correct ML for such a question > (or if there's a more appropriate list for it). > > I'm currently debugging an issue where Linux is not responding to ARP > requests (testing with custom network interface h/w). > > I have 2 network interfaces which are basically interfaces on a custom > network device sitting on the PCI bus. > > My setup looks like follows: > > xeth0 - 192.168.2.1 > xeth2 - 192.168.2.2 > > xeth0/2 are the interfaces created for the custom device (via a lkm) > > Both these interfaces are on the local machine and are connected > back-to-back on the custom device, so packets sent from one arrive on > the other. > > I'm testing this setup by sending a single ARP pack, forced out of one > interface, for the other interface's IP. > > $ sudo arping -c 1 -i xeth0 192.168.2.2 > ARPING 192.168.2.2 > > --- 192.168.2.2 statistics --- > 1 packets transmitted, 0 packets received, 100% unanswered (0 extra) > > If I start tcpdump on the receive interface (xeth2), I see the ARP > packet arrive, but I don't see any response go out (I've attached the > pcap file for anyone interested in looking at the received packet). > The ARP packet's contents seem to be proper under wireshark. > > Is there any statistics I can look at to see if the packet was dropped > by linux during ARP processing? > > I've put debug stmts in the LKM, but I don't see the kernel IP layer > calling the xmit function for an ARP reply (however the xmit function > for the ARP request, from xeth0, is being called). > > > Have you tried to put debug prints in arp_process function? > > > I don't see any drops in "netstat -s" output as well. > > Any hints appreciated. > > > Just a random guess, but try to disable reverse path filtering (rp_filter). > > > Thanks, > -mandeep > > > ???? w??T?g <<?????? ?~e ?~e?? ?? > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@xxxxxxxxxxxxxxxxx > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > > > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@xxxxxxxxxxxxxxxxx > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > > _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
