[pox-dev] Install actions to indirectly connected switches

[Lucas Brasilino]

Hi Ayush:

> I have installed a permanent rule in S1 to forward the packets to S2 that have destination address of S2.

Forwarding at L2, right ? Or are you doing some kind of NAT ?

> Topology: C0 - S1 - S2
> Now, when I want to install rules in S2, how should I go about it?
>
> 1) Should I create a ofp_packet_out with destination of S2, attached ofp_flow_mod packet (rules for S2) as data to it and send it to S1?
>
> 2) Should I create a ofp_flow_mod packet which has destination address of S2 and send it to S1?

Assuming S1 are forwarding at L2, S1 will not be an OpenFlow 'proxy'
for S2. You just need to make S2 connect to C0's IP address. For
instance. if S2 is an Open vSwitch, you just do:

$ sudo ovs-vsctl set-controller s2 tcp:192.168.56.1:6633

Where 192.168.56.1 is the controller's IP address.

-- 
Att
Lucas Brasilino
MSc Student @ Federal University of Pernambuco (UFPE) / Brazil
twitter: @lucas_brasilino

> On Wed, Apr 22, 2015 at 8:19 AM, Lucas Brasilino <lrbbs at cin.ufpe.br> wrote:
>>
>> Hi Ayush,
>>
>> Since controller connects to switch using a TCP session, if S1 acts like a learning switch or already has rules on its flow table
>> allowing TCP connections from C0 to S2, C0 will control S2.
>>
>> Just be aware that if S1 is an OF switch and those rules mentioned above expires, you will lost control over S2, even for a while.
>> What I mean is that until you restore S1 rules, some switch-to-controller messages like 'Packet In', 'Port Status', 'FlowRemoved' and
>> so forth can be lost, leading for a network's state mismatch.
>>
>> --
>> Att
>> Lucas Brasilino
>> MSc Student @ Federal University of Pernambuco (UFPE) / Brazil
>> twitter: @lucas_brasilino
>>
>>
>>
>> 2015-04-22 0:10 GMT-03:00 Ayush Dusia <adusia at udel.edu>:
>>
>>> Hello Everyone,
>>>
>>> I have a question regarding installation of actions in switches.
>>>
>>> If I assume that a controller does not have direct connections to all the switches in a network. In that case how can a controller install actions in a switch to which it is not directly connected?
>>>
>>> e.g. for a topology like: C0 - S1 - S2
>>>
>>> How can C0 install actions in S2 through S1?
>>>
>>> Thanks,
>>> Ayush
>>
>>
>>
>>
>>
>