subnet with a specific set of host routes cannot reach each other

quanuum version: grizzly-1-181-g391d104 folsom-3-258-g6194ab2
os: ubuntu12.04
kernel: Linux ubuntu 3.2.0-23-generic

subnetA 10.0.100.0/24
subnetB 10.0.101.0/24
router1 172.24.4.226(FIP)

issue describtion:
vms in subnetA can not connect with vms in subnetB.
vms in subnetX can reach each other well , and vms also can touch external network through router1.
I do not know the issue whether or not relate with kernel namespace, but i'm sure os device not work well（like /sys/class/net/qr-1e3b11e4-3b）

steps:
0. ## configure quantum *.conf and do some base work
ovs-vsctl add-br br-eth0
ovs-vsctl add-br br-int
ovs-vsctl add-port br-eth0 eth0
ip addr add $IP dev br-eth0
ip addr flush eth0
ifconfig br-eth0 up
ifconfig br-int up

1. ## create two subnets
quantum net-create subnet100
quantum subnet-create subnet100 10.0.100.0/24 --host_routes type=dict list=true destination=10.0.101/24,nexthop=10.0.100.1 ##get subneta_id
quantum net-create subnet101
quantum subnet-create subnet101 10.0.101.0/24 --host_routes type=dict list=true destination=10.0.100/24,nexthop=10.0.101.1 ##get subnetb_id

2.## router interface add
quantum router-create router1
quantum router-interface-add router1 $subneta_id
quantum router-interface-add router1 $subnetb_id

3.## in vma (has ip address 10.0.100.3)
ping 10.0.100.1 (gateway) or 10.0.101.1 ... ok
ping 10.0.100.2 （dhcp server）... ok
ping 10.0.101.3(vmb in subnet 10.0.101.0/24)....failed

## namespace route
root@ubuntu:/opt/stack/quantum# ip netns exec qrouter-df2e23fd-6fc6-4d5b-9f45-4be8ea35b311 route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 172.24.4.225 0.0.0.0 UG 0 0 0 qg-f35c2624-06
10.0.100.0 0.0.0.0 255.255.255.0 U 0 0 0 qr-eb146672-1f
10.0.101.0 0.0.0.0 255.255.255.0 U 0 0 0 qr-1e3b11e4-3b

##ovs-vsctl show
cb3c41d8-129e-4252-af3b-9923422e8afd
    Bridge "br-eth0"
        Port "eth0"
            Interface "eth0"
        Port "phy-br-eth0"
            Interface "phy-br-eth0"
        Port "br-eth0"
            Interface "br-eth0"
                type: internal
    Bridge br-int
        Port "qr-1e3b11e4-3b"
            tag: 3
            Interface "qr-1e3b11e4-3b"
                type: internal
    ...
        Port "tapefb54b36-ca"
            tag: 7
            Interface "tapefb54b36-ca"
                type: internal
        Port "qr-eb146672-1f"
            tag: 2
            Interface "qr-eb146672-1f"
                type: internal
    ...

## ovs-dpctl show
system@br-int:
        lookups: hit:23273 missed:30570 lost:0
        flows: 6
        port 0: br-int (internal)
        port 1: int-br-eth0
        ...
Dec 20 16:25:04|00006|netdev_linux|WARN|/sys/class/net/qr-eb146672-1f/carrier: open failed: No such file or directory
        port 6: qr-eb146672-1f (internal)
Dec 20 16:25:04|00007|netdev_linux|WARN|/sys/class/net/qr-1e3b11e4-3b/carrier: open failed: No such file or directory
        port 7: qr-1e3b11e4-3b (internal)
        ...
        port 18: qvoae90a2b6-93
        port 19: qvoce2db978-c4

## ovs-ofctl show br-int
        ...
 6(qr-eb146672-1f): addr:5d:01:00:00:00:00
     config: PORT_DOWN
     state: LINK_DOWN
 7(qr-1e3b11e4-3b): addr:5d:01:00:00:00:00
     config: PORT_DOWN
     state: LINK_DOWN
        ...

##"ovs-dpctl dump-flows br-int " show nothing in port6 & 7