<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=Windows-1252">
</head>
<body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">
<div style="font-size: 14px; font-family: Calibri, sans-serif; color: rgb(0, 0, 0);">
Hi,</div>
<div style="font-size: 14px; font-family: Calibri, sans-serif; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-size: 14px; font-family: Calibri, sans-serif; color: rgb(0, 0, 0);">
I have seen this issue consistently.</div>
<div style="font-size: 14px; font-family: Calibri, sans-serif; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-size: 14px; font-family: Calibri, sans-serif; color: rgb(0, 0, 0);">
I freshly install Ubuntu 14.04 onto Cisco UCS and use devstack to deploy OpenStack (stable Juno) to make it a Compute node.</div>
<div style="font-size: 14px; font-family: Calibri, sans-serif; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-size: 14px; font-family: Calibri, sans-serif; color: rgb(0, 0, 0);">
For the very first VM launched at this node, it won’t respond to ARP request (I ping from the router namespace).</div>
<div style="font-size: 14px; font-family: Calibri, sans-serif; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-size: 14px; font-family: Calibri, sans-serif; color: rgb(0, 0, 0);">
The Linux bridge tap interface shows it’s sending packets to the VM, and tcpdump confirms it.</div>
<div style="font-size: 14px; font-family: Calibri, sans-serif; color: rgb(0, 0, 0);">
<br>
</div>
<div>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;">qbr8a29c673-4f Link encap:Ethernet HWaddr b2:76:d7:47:c2:fe </p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> inet6 addr: fe80::98ac:73ff:fea8:8be1/64 Scope:Link</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> RX packets:1137 errors:0 dropped:0 overruns:0 frame:0</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> TX packets:8 errors:0 dropped:0 overruns:0 carrier:0</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> collisions:0 txqueuelen:0 </p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> RX bytes:49528 (49.5 KB) TX bytes:648 (648.0 B)</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px; min-height: 14px;">
<br>
</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;">qvb8a29c673-4f Link encap:Ethernet HWaddr b2:76:d7:47:c2:fe </p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> inet6 addr: fe80::b076:d7ff:fe47:c2fe/64 Scope:Link</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> RX packets:1132 errors:0 dropped:0 overruns:0 frame:0</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> TX packets:22 errors:0 dropped:0 overruns:0 carrier:0</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> collisions:0 txqueuelen:1000 </p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> RX bytes:63592 (63.5 KB) TX bytes:3228 (3.2 KB)</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px; min-height: 14px;">
<br>
</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;">qvo8a29c673-4f Link encap:Ethernet HWaddr 9a:2b:5e:e4:22:f9 </p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> inet6 addr: fe80::982b:5eff:fee4:22f9/64 Scope:Link</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> RX packets:22 errors:0 dropped:0 overruns:0 frame:0</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> TX packets:1132 errors:0 dropped:0 overruns:0 carrier:0</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> collisions:0 txqueuelen:1000 </p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> RX bytes:3228 (3.2 KB) TX bytes:63592 (63.5 KB)</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px; min-height: 14px;">
<br>
</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"><b>tap8a29c673-4f</b> Link encap:Ethernet HWaddr fe:16:3e:12:49:10 </p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> inet6 addr: fe80::fc16:3eff:fe12:4910/64 Scope:Link</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> RX packets:7 errors:0 dropped:0 overruns:0 frame:0</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> <b>
TX packets:1143</b> errors:0 dropped:0 overruns:0 carrier:0</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> collisions:0 txqueuelen:500 </p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> RX bytes:2022 (2.0 KB) TX bytes:64490 (64.4 KB)</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; color: rgb(41, 249, 20); margin: 0px; min-height: 14px;">
<br>
</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; color: rgb(41, 249, 20); margin: 0px; min-height: 14px;">
<br>
</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;">localadmin@qa6:~/devstack$ ifconfig tap8a29c673-4f</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"><b>tap8a29c673-4f</b> Link encap:Ethernet HWaddr fe:16:3e:12:49:10 </p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> inet6 addr: fe80::fc16:3eff:fe12:4910/64 Scope:Link</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> RX packets:7 errors:0 dropped:0 overruns:0 frame:0</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> <b>
TX packets:1236</b> errors:0 dropped:0 overruns:0 carrier:0</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> collisions:0 txqueuelen:500 </p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> RX bytes:2022 (2.0 KB) TX bytes:69698 (69.6 KB)</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px; min-height: 14px;">
<br>
</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;">localadmin@qa6:~/devstack$ ifconfig tap8a29c673-4f</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"><b>tap8a29c673-4f</b> Link encap:Ethernet HWaddr fe:16:3e:12:49:10 </p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> inet6 addr: fe80::fc16:3eff:fe12:4910/64 Scope:Link</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> RX packets:7 errors:0 dropped:0 overruns:0 frame:0</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> <b>
TX packets:1239</b> errors:0 dropped:0 overruns:0 carrier:0</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> collisions:0 txqueuelen:500 </p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"> RX bytes:2022 (2.0 KB) TX bytes:69866 (69.8 KB)</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px; min-height: 14px;">
<br>
</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;">localadmin@qa6:~/devstack$ sudo tcpdump -i tap8a29c673-4f</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;">tcpdump: WARNING: tap8a29c673-4f: no IPv4 address assigned</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;">tcpdump: verbose output suppressed, use -v or -vv for full protocol decode</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;">listening on tap8a29c673-4f, link-type EN10MB (Ethernet), capture size 65535 bytes</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;">13:07:31.678751 ARP, Request who-has 10.0.0.14 tell 10.0.0.1, length 42</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;">13:07:32.678813 ARP, Request who-has 10.0.0.14 tell 10.0.0.1, length 42</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;">13:07:32.678838 ARP, Request who-has 10.0.0.14 tell 10.0.0.1, length 42</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;">13:07:33.678778 ARP, Request who-has 10.0.0.14 tell 10.0.0.1, length 42</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;">13:07:34.678840 ARP, Request who-has 10.0.0.14 tell 10.0.0.1, length 42</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"><br>
</p>
<p style="font-size: 12px; font-family: 'Andale Mono'; margin: 0px;"><br>
</p>
<p style="margin: 0px;">Usually I would reboot the VM and the ping works fine afterwards.</p>
<p style="margin: 0px;"><br>
</p>
<p style="margin: 0px; font-size: 12px; font-family: 'Andale Mono';">localadmin@qa6:~/devstack$ sudo tcpdump -i tap8a29c673-4f</p>
<p style="margin: 0px; font-size: 12px; font-family: 'Andale Mono';">tcpdump: WARNING: tap8a29c673-4f: no IPv4 address assigned</p>
<p style="margin: 0px; font-size: 12px; font-family: 'Andale Mono';">tcpdump: verbose output suppressed, use -v or -vv for full protocol decode</p>
<p style="margin: 0px; font-size: 12px; font-family: 'Andale Mono';">listening on tap8a29c673-4f, link-type EN10MB (Ethernet), capture size 65535 bytes</p>
<p style="margin: 0px; font-size: 12px; font-family: 'Andale Mono';">13:13:18.154711 IP 10.0.0.1 > 10.0.0.14: ICMP echo request, id 25711, seq 32, length 64</p>
<p style="margin: 0px; font-size: 12px; font-family: 'Andale Mono';">13:13:18.154996 IP 10.0.0.14 > 10.0.0.1: ICMP echo reply, id 25711, seq 32, length 64</p>
<p style="margin: 0px; font-size: 12px; font-family: 'Andale Mono';">13:13:19.156244 IP 10.0.0.1 > 10.0.0.14: ICMP echo request, id 25711, seq 33, length 64</p>
<p style="margin: 0px;"></p>
<p style="margin: 0px; font-size: 12px; font-family: 'Andale Mono';">13:13:19.156502 IP 10.0.0.14 > 10.0.0.1: ICMP echo reply, id 25711, seq 33, length 64</p>
<p style="margin: 0px; font-size: 12px; font-family: 'Andale Mono';"><br>
</p>
<p style="margin: 0px;">Looking for suggestions on how to debug this issue?</p>
<p style="margin: 0px;"><br>
</p>
<p style="margin: 0px;">Thanks,</p>
<p style="margin: 0px;">Danny</p>
</div>
</body>
</html>