Thank Murphy and Kyriakos for your patient reply, i am sorry that maybe i don't
express my meaning clearly. When a host joins in the network, it receives the
peridictly LLPP packet and reply its own information such as IP, MAC, access
point to the NOX. Then the NOX update the topology immediately when it receives
the host join in event, isn't it? If the toology is update immediately, then
there is a quetion I can't think clealy. If host A sends an ICMP request to
host B, the path_calculation_module says there is no route, it means there is
no path between A and B, isn't it? If so, I think there is no need to
broadcast. This confuses me a lot. I think maybe I was wrong somewhere, can you
help me?
By the way, if A don't have B's MAC, it will send ARP-Reqest first, then what
is the procssing flowchart in NOX? According to NOX debug information, it is
processed by sprouting and broadcasted in network at last.
The command is ./nox_core -v -v -i ptcp:6633 routing.
Wang Jian
2012-7-24
At 2012-07-24 02:59:18,"Murphy McCauley" <[email protected]> wrote:
Adding to what Kyriakos has said...
sprouting is more like something that turns your entire OpenFlow network into
an L2 learning switch, so it behaves the same way -- if it doesn't know where a
destination is, it floods the packet.
Why is this? Well, because there might be a path between the source and
destination and it just doesn't know it yet. The only way it knows where
anything is by seeing a packing FROM it and "learning" its position. So if
host A tries to send to host B, but host B hasn't sent anything yet... you have
no idea where host B is. The two may be connected; you just don't know it.
You'd have to wait for host B to send something before you'd know where to
direct the packets from host A.
By flooding the packet from host A, host B will hopefully get the packet and
then respond. Now you know where host B is and can install exact paths.
-- Murphy
On Jul 23, 2012, at 4:36 AM, 王健 wrote:
Hello guys:
"Default routing component. Listens for Flow_in_events and sets up
shortest path route from source to destination. If no route betweent the
access point datapaths exists, broadcasts packet." The sentence i saw in
src\nox\netapps\routing\sprouting.hh. My Question is why not drop this packet
if there is no route?
