[pox-dev] link detected problem in l2_multi

[Yanan Wu]

I want to achieve the 'multipath' in l2_multi. It means I could neither use the openflow.spanning_tree nor use the stp protocol?

Besides, when the controller sends delayed packet out, there is some openflow error like this.

Why it shows the openflow error ? what kind of influence can the errors have on the "sending delayed packet out"?

DEBUG:test_for_bw:Sending delayed packet out 90-e2-ba-0a-bc-8e
ERROR:openflow.of_01:[90-e2-ba-0a-bc-8e 3] OpenFlow Error:
[90-e2-ba-0a-bc-8e 3] Error: header: 
[90-e2-ba-0a-bc-8e 3] Error:   version: 1
[90-e2-ba-0a-bc-8e 3] Error:   type:    1 (OFPT_ERROR)
[90-e2-ba-0a-bc-8e 3] Error:   length:  36
[90-e2-ba-0a-bc-8e 3] Error:   xid:     2166
[90-e2-ba-0a-bc-8e 3] Error: type: OFPET_BAD_REQUEST (1)
[90-e2-ba-0a-bc-8e 3] Error: code: OFPBRC_BUFFER_UNKNOWN (8)
[90-e2-ba-0a-bc-8e 3] Error: datalen: 24
[90-e2-ba-0a-bc-8e 3] Error: 0000: 01 0d 00 18 00 00 08 76  00 00 01 63 00 02 00 08   .......v...c....
[90-e2-ba-0a-bc-8e 3] Error: 0010: 00 00 00 08 ff f9 00 00

Best Regards,
Yanan
-----Original E-mail-----
From: "Murphy McCauley" <murphy.mccauley at gmail.com>
Sent Time: 2013-6-23 18:16:01
To: Yanan <wyanan at mail.ustc.edu.cn>
Cc: pox-dev at lists.noxrepo.org
Subject: Re: [pox-dev] link detected problem in l2_multi


I am guessing that your switch has an implementation of the Spanning Tree Protocol and is using that to disable links; this is exactly what STP is supposed to do on topologies with loops in order to prevent broadcast storms.


You may be able to disable STP in your switch's configuration.  If you do this, you should run POX's spanning_tree module for the same reason. POX's spanning tree component with l2_multi should allow all shortest paths to be discovered and used by unicasts to known addresses, and should only affect broadcast/multicast/unknown frames (in contrast to the STP built into the switch).


-- Murphy


On Jun 23, 2013, at 2:55 AM, Yanan wrote:


hi,Murphy

I have 3 openvswitch, like this            .

In the discovery, link detected: of-br-10 -> of-br-9      (I just leave out the 'port'). But I cannot get the link " of-br-9 -> of-br-8".
                                             of-br-9  -> of-br-10
                                             of-br-10 -> of-br-8
                                             of-br-8 -> of-br-10
                                             of-br-8 -> of-br-9

wireshark of of-br-8, 
                      I did't have  the PacketIn   "Intel_28_2d_d5  NiciraNe_00:00:01 OFP+LLDP PacketIn"

wireshark of of-br-9,
                             But in the of-br-9, I can see the controller send the LLDP packet to the of-br-9, "Intel_28_2d_d5  NiciraNe_00:00:01 OFP+LLDP PacketOut"


Then I see about the information of bridge of-br-9,  the state of "Intel_28_2d_d5" is STP_BLOCK.  And how to change the state?

In fact , I did not know the 'STP_FORWADING ' or 'STP_BLOCK' very well.   All of this is my guess.

Can u help me t

sdn at IPL209:~$ sudo ovs-ofctl show of-br-9
OFPT_FEATURES_REPLY (xid=0x1): ver:0x1, dpid:000090e2ba282dd5
n_tables:255, n_buffers:256
features: capabilities:0xc7, actions:0xfff
 3(eth6): addr:90:e2:ba:28:2d:d7
     config:     0
     state:      STP_FORWARD
     current:    1GB-FD COPPER AUTO_NEG
     advertised: 10MB-HD 10MB-FD 100MB-HD 100MB-FD 1GB-FD COPPER AUTO_NEG
     supported:  10MB-HD 10MB-FD 100MB-HD 100MB-FD 1GB-FD COPPER AUTO_NEG
 4(eth4): addr:90:e2:ba:28:2d:d5
     config:     0
     state:      STP_BLOCK
     current:    1GB-FD COPPER AUTO_NEG
     advertised: 10MB-HD 10MB-FD 100MB-HD 100MB-FD 1GB-FD COPPER AUTO_NEG
     supported:  10MB-HD 10MB-FD 100MB-HD 100MB-FD 1GB-FD COPPER AUTO_NEG
 LOCAL(of-br-9): addr:90:e2:ba:28:2d:d5
     config:     0
     state:      0
OFPT_GET_CONFIG_REPLY (xid=0x3): frags=normal miss_send_len=0

Best Regards,
Yanan



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