Hi Salman, I'm not familiar with the Ryu plugin, so hopefully you can get in contact with the developers to get this question answered.<div><br></div><div>Dan<br><br><div class="gmail_quote">On Sun, May 13, 2012 at 5:42 PM, Salman Malik <span dir="ltr"><<a href="mailto:salmanmk@live.com" target="_blank">salmanmk@live.com</a>></span> wrote:<br>

<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">


<div><div dir="ltr">
<font style="font-size:10pt" color="#366092" face="Tahoma" size="2">Hi Dan and Others,<br><br>I am trying to understand the actions taken by Ryu when the new instance sends DHCP discover message to dnsmasq. When I launch new instannce it keeps on sending discover messages and controller keeps on dropping these messages. But looking at the traffic I couldn't exactly map which MAC address belonged to which entity. Can someone help me with my understanding of the MAC addresses. Using ifconfig , "ovs-ofctl show br-int" and "ovs-ofctl snoop br-int" (output shown after MAC addresses), I know exactly about some MAC addresses and can't figure out some of them:<br>

<br>Interfaces              |        HWAddress          |        IP-addr<br>---------------------------------------------------------------------------------------------<br>eth0                        |        08:00:27:7a:ff:65    |    10.0.3.15<br>

eth1                        |        08:00:27:16:d5:09  |    10.0.0.10             <========plugged into br-int<br>gw-82bd3a73-dc    |        fa:16:3e:49:57:1b  |    10.0.0.1               <========plugged into br-int (this is the --listen-address of my two dnsmasqs)<br>

br-int                       |        08:00:27:16:d5:09 |                                <========why doesn't bridge have no IP ?<br>new-instance          |        <b>02:d8:47:48:35:26</b>  <====== MAC address of newly launched instance? (see output below)<br>

<br><b>Unkown</b>                 |        </font><font style="font-size:10pt" color="#366092" face="Tahoma" size="2"><b>fa:16:3e:5e:02:17   </b><======Seemingly unknown MAC address(which is related to the new instance?)</font><br>

<font style="font-size:10pt" color="#366092" face="Tahoma" size="2">Unkown                  |        </font><font style="font-size:10pt" color="#366092" face="Tahoma" size="2"><b>33:33:00:00:00:16</b></font><font style="font-size:10pt" color="#366092" face="Tahoma" size="2"><b>   </b><====== MAC address related to multicast ?</font><br>

<br><br><font color="#366092"><font style="font-size:10pt" size="2"><font face="Tahoma">Questions:<br><br>1. What is </font></font></font><font style="font-size:10pt" color="#366092" face="Tahoma" size="2">gw-82bd3a73-dc interface ?<br>

2. I am kind of unsure why br-int is so useful? <br>3. Why doesn't br-int don't have any IP address?<br>4. Why do we need to plugin a compute node's interface to br-int? (so that guest instances on remote host can communicate with each other?)<br>

5. What is the relationship b/w </font><font style="font-size:10pt" color="#366092" face="Tahoma" size="2"><b>02:d8:47:48:35:26 and </b></font><font style="font-size:10pt" color="#366092" face="Tahoma" size="2"><b>fa:16:3e:5e:02:17 </b>MAC addresses in the following output?</font><br>

<font style="font-size:10pt" color="#366092" face="Tahoma" size="2"><br>=====================<br></font><font style="font-size:10pt" color="#366092" face="Tahoma" size="2">Output of : ovs-ofctl snoop br-int <br>=====================<br>

</font><font style="font-size:10pt" color="#366092" face="Tahoma" size="2">OFPT_ECHO_REQUEST (xid=0x0): 0 bytes of payload<br>OFPT_ECHO_REPLY (xid=0x0): 0 bytes of payload<br>OFPT_PORT_STATUS (xid=0x0): ADD: 7(tap76127847-b1): addr:<b>02:d8:47:48:35:26</b><br>

     config:     0<br>     state:      LINK_DOWN<br>     current:    10MB-FD COPPER<br>OFPT_FLOW_MOD (xid=0x491662da): DEL priority=0 buf:0x0 actions=drop<br>OFPT_BARRIER_REQUEST (xid=0x491662db):<br>OFPT_BARRIER_REPLY (xid=0x491662db):<br>

OFPT_PORT_STATUS (xid=0x0): MOD: 7(tap76127847-b1): addr:<b>02:d8:47:48:35:26</b><br>     config:     0<br>     state:      0<br>     current:    10MB-FD COPPER<br>OFPT_ECHO_REQUEST (xid=0x0): 0 bytes of payload<br>OFPT_ECHO_REPLY (xid=0x0): 0 bytes of payload<br>

OFPT_PACKET_IN (xid=0x0): total_len=90 in_port=7 data_len=90 buffer=0x00000167<br>tunnel0:in_port0007:tci(0) macfa:16:3e:5e:02:17->33:33:00:00:00:16 type86dd proto58 tos0 ipv6::->ff02::16 port143->0<br><b>fa:16:3e:5e:02:17 </b>> <b>33:33:00:00:00:16</b>, ethertype IPv6 (0x86dd), length 90: :: > ff02::16: HBH ICMP6, multicast listener report v2, 1 group record(s), length 28<br>

OFPT_PACKET_OUT (xid=0x491662dc): in_port=7 actions_len=0 actions=drop buffer=0x00000167<br>OFPT_PACKET_IN (xid=0x0): total_len=322 in_port=7 data_len=128 buffer=0x00000168<br>tunnel0:in_port0007:tci(0) macfa:16:3e:5e:02:17->ff:ff:ff:ff:ff:ff type0800 proto17 tos0 ip0.0.0.0->255.255.255.255 port68->67<br>

<b>fa:16:3e:5e:02:17</b> > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 128: truncated-ip - 194 bytes missing! 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fa:16:3e:5e:02:17, length 280<br>OFPT_PACKET_OUT (xid=0x491662dd): in_port=7 actions_len=0 actions=<b>drop</b> buffer=0x00000168<br>

OFPT_PACKET_IN (xid=0x0): total_len=78 in_port=7 data_len=78 buffer=0x00000169<br><b>fa:16:3e:5e:02:17</b> > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 128: truncated-ip - 194 bytes missing! 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fa:16:3e:5e:02:17, length 280<br>

OFPT_PACKET_OUT (xid=0x491662e3): in_port=7 actions_len=0 actions=drop buffer=0x0000016e<br>OFPT_PACKET_IN (xid=0x0): total_len=70 in_port=7 data_len=70 buffer=0x0000016f<br>tunnel0:in_port0007:tci(0) macfa:16:3e:5e:02:17->33:33:00:00:00:02 type86dd proto58 tos0 ipv6fe80::f816:3eff:fe5e:217->ff02::2 port133->0<br>

fa:16:3e:5e:02:17 > 33:33:00:00:00:02, ethertype IPv6 (0x86dd), length 70: fe80::f816:3eff:fe5e:217 > ff02::2: ICMP6, router solicitation, length 16<br>OFPT_PORT_STATUS (xid=0x0): MOD: 7(tap76127847-b1): addr:<b>02:d8:47:48:35:26</b><br>

     config:     0<br>     state:      LINK_DOWN<br>     current:    10MB-FD COPPER<br>OFPT_PORT_STATUS (xid=0x0): DEL: 7(tap76127847-b1): addr:<b>02:d8:47:48:35:26</b><br>     config:     0<br>     state:      LINK_DOWN<br>

     current:    10MB-FD COPPER<br>OFPT_FLOW_MOD (xid=0x491662e5): DEL priority=0,in_port=7 actions=drop<br>OFPT_FLOW_MOD (xid=0x491662e6): DEL priority=0 actions=drop<br>OFPT_BARRIER_REQUEST (xid=0x491662e7):<br>OFPT_BARRIER_REPLY (xid=0x491662e7):<br>

<br>Thanks!<span class="HOEnZb"><font color="#888888"><br>Salman<br></font></span></font>                                     </div></div>
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<br></blockquote></div><br><br clear="all"><div><br></div>-- <br>~~~~~~~~~~~~~~~~~~~~~~~~~~~<br>Dan Wendlandt <div>Nicira, Inc: <a href="http://www.nicira.com" target="_blank">www.nicira.com</a><br><div>twitter: danwendlandt<br>

~~~~~~~~~~~~~~~~~~~~~~~~~~~<br></div></div><br>
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