[pox-dev] POX - TCP redirection flows

[Murphy McCauley]

On May 15, 2013, at 2:14 AM, chenli wrote:

> I did some test again, and it's so strange that the back flow for ssh connection needs the field of nw_tos=16.

I don't think this is strange.  I believe 16 is the TOS value for minimize delay, which makes sense for ssh, since it's interactive.  The server is likely setting it on purpose.

> If the field for nw_tos equals to 0, the flow can't match correctly. Just like below

I'm not clear why this a problem.  If its really troublesome for some reason, you could always wildcard it...

> And how can I find the flow_mods that correspond to these flows in POX?

That depends on what application you're running in POX.  If you're using l2_learning, for example, it's wherever the flow_mod is in there.  l2_learning uses ofp_match.from_packet() to create a flow which exactly matches the packet it's given.  This includes the TOS field.  You could just insert a match.nw_tos = None to wildcard it...


-- Murphy