The interfaces on s0 and s1 that connect to the other nodes in your topology
are part of an Open vSwitch datapath. Thus, packets on them do not go through
the normal Linux networking stack and do not have corresponding entries in the
Linux routing table. Instead, they are processed by OVS's tables. You can
view these with the OVS tools, e.g., ovs-ofctl.
If you want to check the path of a packet, you can also pay attention to which
table entries POX actually sends to the switches...
-- Murphy
On May 29, 2013, at 11:42 PM, hansinie vitharana wrote:
> Hi,
> I am very new to POX and mininet and I have a small question about routing
> tables
> I create following topology
> h1 --- s0 ----- s1 --- h2
>
> h1 = net.addHost('h1',ip='10.1.0.1')
> h2 = net.addHost('h2',ip='11.1.0.2')
> So h1 and h2 are in two different subnets..
> I run the mininet script with POX contoller and I am using l2_learning in POX
> controller.
> Then I give following commands in mininet, so i can have connectivity between
> subnets
>
> mininet> h1 route add -net default h1-eth0
> mininet> h2 route add -net default h2-eth0
> when I ping from h1 to h2, its sucessful
>
> when I look at the routing table of h1
>
> mininet> h1 route
> Kernel IP routing table
> Destination Gateway Genmask Flags Metric Ref Use Iface
> default * 0.0.0.0 U 0 0 0
> h1-eth0
> 10.0.0.0 * 255.0.0.0 U 0 0 0
> h1-eth0
>
> when I look at the routing table of switch s0
>
> mininet> s0 route
> Kernel IP routing table
> Destination Gateway Genmask Flags Metric Ref Use Iface
> default 10.80.7.245 0.0.0.0 UG 0 0 0 eth0
> 10.80.4.0 * 255.255.252.0 U 1 0 0 eth0
> link-local * 255.255.0.0 U 1000 0 0 eth0
> As far as I know when h1 ping to h2, S0 switch should learn about the new
> network and its routing table should include information about 11.0.0.0
> network..
> But even after ping, there is no entry for 11.0.0.0 in S0
> Am I missing something here ? Whats wrong with the routing table ?
> I want to check the path of the packet and thats why I am looking at the
> routing tables.. Is there any other way to check the path of the packets ?
