> If you ping the the ROACH from the PC (e.g. run "ping 10.0.0.20" on the > PC), does it get replies? What does "arp -a" show afterwards?
[r...@arcons controlScripts]# ping 10.0.0.20 PING 10.0.0.20 (10.0.0.20) 56(84) bytes of data. >From 10.0.0.30 icmp_seq=1 Destination Host Unreachable >From 10.0.0.30 icmp_seq=2 Destination Host Unreachable >From 10.0.0.30 icmp_seq=3 Destination Host Unreachable >From 10.0.0.30 icmp_seq=5 Destination Host Unreachable >From 10.0.0.30 icmp_seq=6 Destination Host Unreachable >From 10.0.0.30 icmp_seq=7 Destination Host Unreachable --- 10.0.0.20 ping statistics --- 8 packets transmitted, 0 received, +6 errors, 100% packet loss, time 7000ms , pipe 3 [r...@arcons controlScripts]# /sbin/arp -a physgw-23.deepspace.ucsb.edu (128.111.23.8) at 00:D0:2B:E5:E1:00 [ether] on eth0 ? (10.0.0.20) at <incomplete> on eth1 Note, "eth1" is the 10gb nic on this PC. Thanks, Sean > Hi Sean, > > On Oct 29, 2010, at 2:10 PM, [email protected] wrote: > >> Here are the outputs of print_10gbe_core_details and tcpdump. It looks >> to >> me that the ARP table is configured properly. Do you still see >> something >> funny in the received packet? >> >> ARP Table: >> IP: 10. 0. 0. 20: MAC: 02 02 0A 00 00 14 >> IP: 10. 0. 0. 30: MAC: FF FF FF FF FF FF > > The ROACH's ARP table has an entry for itself (10.0.0.20), but it does not > have a valid MAC address for the PC (10.0.0.30), which leads to... > >> [r...@arcons controlScripts]# /usr/sbin/tcpdump -xx -i eth1 -c 1 >> tcpdump: verbose output suppressed, use -v or -vv for full protocol >> decode >> listening on eth1, link-type EN10MB (Ethernet), capture size 96 bytes >> 13:53:27.263857 IP 10.0.0.20.60000 > 10.0.0.30.60000: UDP, length 4104 >> 0x0000: ffff ffff ffff 0202 0a00 0014 0800 4500 >> 0x0010: 1024 0000 4000 ff11 5797 0a00 0014 0a00 >> 0x0020: 001e ea60 ea60 1010 0000 0000 0000 0000 >> 0x0030: 0000 0000 0000 0000 0000 0000 0000 0000 >> 0x0040: 0000 0000 0000 0000 0000 0000 0000 0000 >> 0x0050: 0000 0000 0000 0000 0000 0000 0000 0000 > > This packet still has broadcast Ethernet address and unicast IP address. > It seems like for some reason that ROACH is not sending the PC an ARP > request OR the firewall is blocking the ARP request OR the firewall is > blocking the ARP response OR the ARP response is not being properly > addressed/routed to the right egress interface. > > If you ping the the ROACH from the PC (e.g. run "ping 10.0.0.20" on the > PC), does it get replies? What does "arp -a" show afterwards? > > Hope this helps, > Dave > > >
