Got it. Thanks!
Best,Himanshu Shahwww.cs.stonybrook.edu/~hkshah/(609) 647-2765
Subject: Re: [pox-dev] Bringing Links up and down from the pox controller
From: murphy.mccau...@gmail.com
Date: Wed, 12 Mar 2014 16:40:42 -0700
CC: pox-dev@lists.noxrepo.org
To: himanshu1...@live.com
I guess what you're saying here is that you think setting the port down on one
switch should change the link state on the port connected to the other side of
the link? That's possibly but not necessarily true. I don't think OpenFlow
specifies exactly what a "down" port means... it could just ignore packets sent
to or from it, in which case, the link state wouldn't change on the other end.
Similarly, the link state on the second switch wouldn't change if there was a
dumb bridge between the two switches.
And while I'd expect bringing a port down via config *might* change the link
state, a change in the link state would *not* change the port config.
-- Murphy
On Mar 12, 2014, at 4:31 PM, Himanshu Shah <himanshu1...@live.com> wrote:Hi
Murphy,
Thanks a lot for the pointer for (1). It worked like a charm. I have a question
though.
Q1:
What will be the changes in the port's configuration (I think the port.state
and port.config changes)?
Consider a topology H1(1) -(1)S1(2) - (2)S2(2) -(1)H2 Values in the brackets
are port numbers==> port (2)down on S1: state changes from 0 -> 1
config changes from 0 -> 1and for port (2) on S2 state changes from 0->1
config changes from 0->0
and on bringing the port back up the values change the other way. Is my
understanding correct?
Thank you,Himanshu Shahwww.cs.stonybrook.edu/~hkshah/(609) 647-2765
Subject: Re: [pox-dev] Bringing Links up and down from the pox controller
From: murphy.mccau...@gmail.com
Date: Tue, 11 Mar 2014 19:43:23 -0700
CC: pox-dev@lists.noxrepo.org
To: himanshu1...@live.com
On Mar 11, 2014, at 3:57 PM, Himanshu Shah <himanshu1...@live.com> wrote:Hello
all,
1 - I am interested in bringing links/ports up and down from the controller on
the fly. Bringing the port down works well using of.OFPPC_PORT_DOWN
however, I don't know how can one bring the port backup.
Un-set the port down bit by leaving its value as 0 in the config, but setting
the mask to 1.
2 - what is the switch_impl.py used for? Is the idea to create SwitchImpl
objects on connectionup, and use these objects in controlling the switches in
mininet?
First, there has not been such a thing for a while and your POX is probably
rather out of date. The code that was SwitchImpl is now in the datapaths
package and has been fairly dramatically altered.
And no. SwitchImpl (and the stuff that replaces it) isn't generally meant to
be part of a controller. It's an actual OpenFlow switch (like the reference
OpenFlow switch or Open vSwitch but slower). This is both slightly clearer and
the code is more immediately usable in newer versions of POX.
-- Murphy
