I think malformed tcp packets are dropped by authenticator module, but
udp packets will still generate flow_in event.
I run routing and spanning_tree module. I did a simple test to
tcpreplay the truncated packets. All of them generated packet_in
event, which are captured by the control channel.
I added a simple line to sprouting.cc, function set_route():
if(fi.flow.nw_proto==ip_::proto::TCP)
VLOG_DBG(lg, "Broadcasting %"PRIx64" %s",
fi.datapath_id.as_host(), os.str().c_str());
This let TCP packets be printed out if they are broadcasted (which is
true since there is no path for them in my case).
Then, I find that no TCP truncated packets printed out. If I delete
the if() judgement, this line is printed out.
This shows that malformed tcp packets will not generate flow_in event.
But truncated ICMP and UDP packets donot have such problem.
Thanks.
On Thu, Mar 11, 2010 at 1:37 PM, Martin Casado <[email protected]> wrote:
> I'm not exactly sure what you're doing. If the openflow headers have become
> corrupted, then the openflow stack will drop the packets without generating
> events.
>
>> Hi
>> Sorry to bother others.
>> My program needs to tcpreplay some packets between switches. Since the
>> trace is from raw IP, I converted them to ethernet packets. However,
>> some of the original packets are truncated, and I found these packets
>> are forwarded but missed.
>> If I tcpreplay them and tcpdump the interface, I saw these packets
>> become [Malformed packet]. My module even didnt capture a flow_in
>> event for these packets.
>> So, I am wondering, where are these packets actually dropped? Are they
>> dropped by IP stack or are they dropped by authenticator module? Our
>> control in nox is above or below IP stack??
>> Thanks.
>>
>> _______________________________________________
>> nox-dev mailing list
>> [email protected]
>> http://noxrepo.org/mailman/listinfo/nox-dev_noxrepo.org
>>
>
>
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