Hi,
On 2015年08月24日 17:13, Daniel Herrmann wrote:
> Hi Iwase,
>
> thank you very much for your answer.
>
> NXActionResubmitTable sounds promising, I will give it a try.
>
> This however leaves one problem to me: Lets say I have a group with 4
> buckets, one of them is selected based on some kind of hashing. If I use
> NXActionResubmitTable to resubmit this to a table, how can I distinguish
> which bucket has forwarded the packet?
>
> My first idea was to add four different metadata values and match on the
> metadata in the next table, bit adding metadata is an instruction as well.
>
> In the Nicria extended actions, I have found no action which would match
> my need. The only other Idea I currently have is to create four
> different tables, and add another step of indirection. Something like
>
> Table 0: match in port and prefix, go to Group Table (Group n)
> Group n: 4 buckets, select one, go to table 2, 3, 4, or 5
> Tables 2-5: match prefix again, add different metadata, for example
> ("13" in table 2, "14" in table 3, and so on) and all go to table 10
First, why do you need to use GroupTable?
I think setting MPLS tag based on in_port and prefix and forwarding it
can be done with only FlowTable.
e.g.)
Table 0: match in_port and prefix, write metadata and go to Table 1.
Table 1: match metadata, modify packet and go to Table 2.
Table 2: match metadata, push and set MPLS tags and go to Table 3.
Table 3: match metadata or MPLS tags, output packet.
>
> There I have to add a variable stack (min 1, max 3) of MPLS headers. As
> far as I know, only one MPLS header can be pushed per table. Matchin on
> each of those tables is done using the metadata set before. Hence:
>
> Table 10: add MPLS header + tag, if done output else goto table 11
> Table 11: add MPLS header + tag, if done output else goto table 12
> Table 12: add MPLS header + tag, output
With Open vSwitch, multiple MPLS tags can be pushed per table.
e.g.) I used ofctl_rest.py
$ curl -X POST -d '{
> "dpid": "1",
> "match":{
> "in_port":1
> },
> "actions":[
> {
> "type": "PUSH_MPLS",
> "ethertype": 34887
> },
> {
> "type": "SET_FIELD",
> "field": "mpls_label",
> "value": 3
> },
> {
> "type": "PUSH_MPLS",
> "ethertype": 34887
> },
> {
> "type": "SET_FIELD",
> "field": "mpls_label",
> "value": 5
> },
> {
> "type": "PUSH_MPLS",
> "ethertype": 34887
> },
> {
> "type": "SET_FIELD",
> "field": "mpls_label",
> "value": 7
> },
> {
> "port":2,
> "type":"OUTPUT"
> }
> ]
> }' http://localhost:8080/stats/flowentry/add
$
$ curl -X GET http://localhost:8080/stats/flow/1 | jq .
{
"1": [
{
"match": {
"in_port": 1
},
"flags": 0,
"table_id": 0,
"duration_sec": 0,
"priority": 0,
"actions": [
"PUSH_MPLS:34887",
"SET_FIELD: {mpls_label:3}",
"PUSH_MPLS:34887",
"SET_FIELD: {mpls_label:5}",
"PUSH_MPLS:34887",
"SET_FIELD: {mpls_label:7}",
"OUTPUT:2"
],
"idle_timeout": 0,
"cookie": 0,
"packet_count": 0,
"hard_timeout": 0,
"byte_count": 0,
"length": 160,
"duration_nsec": 1.2e+07
}
]
}
>
> I think that should work, but if there was an action to add metadata,
> this would remove the need for tables 2 - 5.
As far as I know, WRITE_METADATA Instruction can not be used in GroupTable.
So I think you should use FlowTable to write metadata.
Thanks,
Iwase
>
> Thanks and best regards
> Daniel
>
> On 24.08.2015 02:27, Yusuke Iwase wrote:
>> Hi,
>>
>> On 2015年08月23日 00:38, Daniel Herrmann wrote:
>>> Hi,
>>>
>>> I am using Ryu and OVS in order to set up some tests. I need to do the
>>> following:
>>>
>>> Table 0 matches on some factors such as IP addresses and so on and
>>> forwards the processing to a specific group ID.
>>>
>>> Based on the group result I need to add multiple MPLS headers. As I
>>> cannot push multiple headers in one table, I am using Table 10 - 12 to
>>> push MPLS headers.
>>>
>>> The basic idea now is:
>>>
>>> Match on Table 0 and forward to group table. There, n Buckets are
>>> present, let us say 4 buckets. Each bucket should assign one metadata
>>> value (for example 1-4) and go to table 10 for further processing. Based
>>> on the metadata, tables 10 - 12 add the required label stack and finally
>>> output the packet on the right port.
>>>
>>> My understanding of OFPGroupMod however is, that it takes actions as
>>> argument. Adding metadata and going to another table however is an
>>> instruction.
>>
>> As you say, OpenFlow Spec does not allow GoToTable instruction in GroupTable,
>> only actions are permitted.
>>
>> But if you use OVS, NXActionResubmitTable, which is Nicira Extended Action,
>> maybe available in GroupTable.
>> https://github.com/osrg/ryu/blob/master/ryu/ofproto/nx_actions.py#L383
>>
>> Thanks,
>> Iwase
>>
>>>
>>> Do you have any idea how to solve this?
>>>
>>> VG
>>> Daniel
>>>
>>> ------------------------------------------------------------------------------
>>> _______________________________________________
>>> Ryu-devel mailing list
>>> [email protected]
>>> https://lists.sourceforge.net/lists/listinfo/ryu-devel
>>>
>
------------------------------------------------------------------------------
_______________________________________________
Ryu-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/ryu-devel
