netmap: how to bridge 2 eth?

[upyzl]

Hi all

I'm doing to implement a simple openflow-based software switch(not same as
OVS, much simpler to OVS)
and I choose netmap for the network framework

Now I try to do a simplest thing:

there's 3 VMs, all are Ubuntu 12.04.4 x64
2 act as hosts, other 1 act as switch

topo:  [host1] eth0 ----- eth0 [switch] eth1 ----- eth0 [host2]

I want to bridge switch's eth0&eth1 (like "brctl" in linux), then host1
ping host2

the problem is, how to bridge using netmap?

I tried example "bridge" in netmap project(git clone
https://code.google.com/p/netmap/):
./bridge -i netmap:eth0 -i netmap:eth1
then host1 ping to host2
but pinging result is "Destination Host Unreachable" (if using brctl,
pinging is fine)

Then I tried vale-ctl
but i dont know how to use it...
e.g.
./vale-ctl -a eth0
show
"eth0: Invalid argument"

could anyone help me?