X-Git-Url: http://git.cascardo.eti.br/?a=blobdiff_plain;f=tests%2Fbfd.at;h=925af77a6cff9bf316e2960539efe95813ed2bf1;hb=ca5792f0d80ffd5202dfe2db9baba356c33461fa;hp=3154909e69ccabe54afbdb4807fcb979824c8e71;hpb=635c5db93df8c69db6289c58ebda0e64cea85c9b;p=cascardo%2Fovs.git

diff --git a/tests/bfd.at b/tests/bfd.at
index 3154909e6..925af77a6 100644
--- a/tests/bfd.at
+++ b/tests/bfd.at
@@ -34,6 +34,14 @@ AT_CHECK([ovs-appctl bfd/show $1 | sed -n '/RX Interval/p'],[0],
 	Remote Minimum RX Interval: $4
 ])
 ])
+
+m4_define([BFD_VSCTL_LIST_IFACE], [
+AT_CHECK([ovs-vsctl list interface $1 | sed -n $2],[0],
+[dnl
+$3
+])
+])
+
 AT_SETUP([bfd - basic config on different bridges])
 #Create 2 bridges connected by patch ports and enable BFD
 OVS_VSWITCHD_START(
@@ -47,18 +55,18 @@ OVS_VSWITCHD_START(
     set Interface p0 bfd:enable=true -- \
     set Interface p1 bfd:enable=true ])
 ovs-appctl time/stop
-for i in `seq 0 40`; do ovs-appctl time/warp 100; done
+ovs-appctl time/warp 4100 100
 
 #Verify that BFD has been enabled on both interfaces.
 BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
 BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
 
 AT_CHECK([ ovs-vsctl set interface p0 bfd:enable=false])
-for i in `seq 0 40`; do ovs-appctl time/warp 100; done
+ovs-appctl time/warp 4100 100
 BFD_CHECK([p1], [false], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
 
 AT_CHECK([ ovs-vsctl set interface p0 bfd:enable=true])
-for i in `seq 0 40`; do ovs-appctl time/warp 100; done
+ovs-appctl time/warp 4100 100
 BFD_CHECK([p1], [true], [false], [none], [up], [Control Detection Time Expired], [none], [up], [No Diagnostic])
 BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [Control Detection Time Expired])
 
@@ -93,9 +101,9 @@ OVS_VSWITCHD_START(
        set bridge br-sw datapath-type=dummy \
        other-config:hwaddr=aa:55:aa:58:00:00 -- \
     add-port br-sw p1-sw -- set Interface p1-sw type=patch \
-       options:peer=p1 -- \
+       options:peer=p1 ofport_request=2 -- \
     add-port br-sw p0-sw -- set Interface p0-sw type=patch \
-       options:peer=p0 -- \
+       options:peer=p0 ofport_request=1 -- \
     add-port br-bfd1 p1 -- set Interface p1 type=patch \
        options:peer=p1-sw bfd:enable=true -- \
     add-port br-bfd0 p0 -- set Interface p0 type=patch \
@@ -107,13 +115,13 @@ ovs-appctl time/stop
 
 AT_CHECK([ovs-ofctl add-flow br-sw 'priority=0,actions=NORMAL'])
 #Verify that BFD is enabled.
-for i in `seq 0 40`; do ovs-appctl time/warp 100; done
+ovs-appctl time/warp 4100 100
 BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
 BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
 
 #Drop all packets in the br-sw bridge so that the tunnel is down.
 AT_CHECK([ ovs-ofctl add-flow br-sw 'priority=5,actions=drop' ])
-for i in `seq 0 40`; do ovs-appctl time/warp 100; done
+ovs-appctl time/warp 4100 100
 BFD_CHECK([p1], [false], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
 BFD_CHECK([p0], [false], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
 
@@ -121,7 +129,7 @@ BFD_CHECK([p0], [false], [false], [none], [down], [Control Detection Time Expire
 AT_CHECK([ovs-ofctl del-flows br-sw], [0])
 AT_CHECK([ovs-ofctl add-flow br-sw 'priority=0,actions=NORMAL'])
 #Verify that BFD is back up again.
-for i in `seq 0 40`; do ovs-appctl time/warp 100; done
+ovs-appctl time/warp 4100 100
 
 BFD_CHECK([p1], [true], [false], [none], [up], [Control Detection Time Expired], [none], [up], [Control Detection Time Expired])
 BFD_CHECK([p0], [true], [false], [none], [up], [Control Detection Time Expired], [none], [up], [Control Detection Time Expired])
@@ -134,10 +142,11 @@ BFD_CHECK([p0], [true], [false], [none], [up], [Control Detection Time Expired],
 # but not received by p1. p0 will receive all BFD packets from p1.
 
 AT_CHECK([ ovs-ofctl add-flow br-sw 'in_port=1,priority=5,actions=drop'])
-for i in `seq 0 40`; do ovs-appctl time/warp 100; done
+ovs-appctl time/warp 4100 100
 # Make sure p1 BFD state is down since it received no BFD packets.
 BFD_CHECK([p1], [false], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
-for i in `seq 0 40`; do ovs-appctl time/warp 100; done
+ovs-appctl time/warp 4100 100
+
 # p0 will be in init state once it receives "down" BFD message from p1.
 BFD_CHECK([p0], [false], [false], [none], [init], [Neighbor Signaled Session Down], [none], [down], [Control Detection Time Expired])
 
@@ -145,12 +154,12 @@ AT_CHECK([ovs-ofctl del-flows br-sw])
 AT_CHECK([ovs-ofctl add-flow br-sw 'priority=0,actions=NORMAL'])
 #Ensure that BFD is back up again.
 
-for i in `seq 0 10`; do ovs-appctl time/warp 100; done
+ovs-appctl time/warp 1100 100
 #Bring down the br-bfd0 - br-sw link
 AT_CHECK([ ovs-ofctl add-flow br-sw 'in_port=2,priority=5,actions=drop'])
-for i in `seq 0 40`; do ovs-appctl time/warp 100; done
+ovs-appctl time/warp 4100 100
 BFD_CHECK([p0], [false], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
-for i in `seq 0 40`; do ovs-appctl time/warp 100; done
+ovs-appctl time/warp 4100 100
 BFD_CHECK([p1], [false], [false], [none], [init], [Neighbor Signaled Session Down], [none], [down], [Control Detection Time Expired])
 OVS_VSWITCHD_STOP
 AT_CLEANUP
@@ -169,7 +178,7 @@ AT_CHECK([ ovs-vsctl -- add-port br0 p0 -- set Interface p0 type=patch \
            options:peer=p1 ])
 AT_CHECK([ ovs-vsctl -- set interface p0 bfd:enable=true ])
 AT_CHECK([ ovs-vsctl -- set interface p1 bfd:enable=true ])
-for i in `seq 0 40`; do ovs-appctl time/warp 100; done
+ovs-appctl time/warp 4100 100
 
 #Verify that BFD has been enabled on both interfaces.
 BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
@@ -177,7 +186,7 @@ BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [N
 
 #Set cpath_down to true on one interface, make sure the remote interface updates its values.
 AT_CHECK([ovs-vsctl set interface p0 bfd:cpath_down=true])
-for i in `seq 0 40`; do ovs-appctl time/warp 100; done
+ovs-appctl time/warp 4100 100
 BFD_CHECK([p1], [false], [false], [none], [up], [No Diagnostic], [none], [up], [Concatenated Path Down])
 OVS_VSWITCHD_STOP
 AT_CLEANUP
@@ -195,19 +204,19 @@ AT_CHECK([ ovs-vsctl -- add-port br0 p0 -- set Interface p0 type=patch \
            options:peer=p1 ])
 AT_CHECK([ ovs-vsctl -- set interface p0 bfd:enable=true ])
 AT_CHECK([ ovs-vsctl -- set interface p1 bfd:enable=true ])
-for i in `seq 0 30`; do ovs-appctl time/warp 100; done
+ovs-appctl time/warp 3100 100
 #Verify that BFD has been enabled on both interfaces.
 BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
 BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
 #Edit the min Tx value.
 AT_CHECK([ovs-vsctl set interface p0 bfd:min_tx=200])
-for i in `seq 0 20`; do ovs-appctl time/warp 100; done
+ovs-appctl time/warp 2100 100
 BFD_CHECK_TX([p0], [1000ms], [200ms], [100ms])
 BFD_CHECK_TX([p1], [1000ms], [100ms], [200ms])
 
 #Edit the min Rx value.
 AT_CHECK([ovs-vsctl set interface p1 bfd:min_rx=300])
-for i in `seq 0 20`; do ovs-appctl time/warp 100; done
+ovs-appctl time/warp 2100 100
 BFD_CHECK_RX([p1], [300ms], [300ms], [1000ms])
 BFD_CHECK_RX([p0], [1000ms], [1000ms], [300ms])
 
@@ -221,7 +230,7 @@ OVS_VSWITCHD_START([add-port br0 p1 -- set Interface p1 type=gre \
                     set bridge br0 fail-mode=standalone])
 
 # by default check_tnl_key is false. so we should process a bfd packet with tun_id=1.
-AT_CHECK([ovs-appctl ofproto/trace ovs-dummy 'tunnel(tun_id=0x1,src=2.2.2.2,dst=2.2.2.1,tos=0x0,ttl=64,flags(key)),in_port(1),skb_mark(0/0),eth(src=00:11:22:33:44:55,dst=00:23:20:00:00:01),eth_type(0x0800),ipv4(src=169.254.1.0/0.0.0.0,dst=169.254.1.1/0.0.0.0,proto=17/0xff,tos=0/0,ttl=255/0,frag=no/0xff),udp(src=49152/0,dst=3784/0xffff)' -generate], [0], [stdout])
+AT_CHECK([ovs-appctl ofproto/trace ovs-dummy 'tunnel(tun_id=0x1,src=2.2.2.2,dst=2.2.2.1,tos=0x0,ttl=64,tp_src=0,tp_dst=0,flags(key)),in_port(1),skb_mark(0/0),eth(src=00:11:22:33:44:55,dst=00:23:20:00:00:01),eth_type(0x0800),ipv4(src=169.254.1.0/0.0.0.0,dst=169.254.1.1/0.0.0.0,proto=17/0xff,tos=0/0,ttl=255/0,frag=no),udp(src=49152/0,dst=3784/0xffff)' -generate], [0], [stdout])
 # check that the packet should be handled as BFD packet.
 AT_CHECK([tail -2 stdout], [0], [dnl
 This flow is handled by the userspace slow path because it:
@@ -230,7 +239,7 @@ This flow is handled by the userspace slow path because it:
 
 # turn on the check_tnl_key.
 AT_CHECK([ovs-vsctl set interface p1 bfd:check_tnl_key=true])
-AT_CHECK([ovs-appctl ofproto/trace ovs-dummy 'tunnel(tun_id=0x1,src=2.2.2.2,dst=2.2.2.1,tos=0x0,ttl=64,flags(key)),in_port(1),skb_mark(0/0),eth(src=00:11:22:33:44:55,dst=00:23:20:00:00:01),eth_type(0x0800),ipv4(src=169.254.1.0/0.0.0.0,dst=169.254.1.1/0.0.0.0,proto=17/0xff,tos=0/0,ttl=255/0,frag=no/0xff),udp(src=49152/0,dst=3784/0xffff)' -generate], [0], [stdout])
+AT_CHECK([ovs-appctl ofproto/trace ovs-dummy 'tunnel(tun_id=0x1,src=2.2.2.2,dst=2.2.2.1,tos=0x0,ttl=64,tp_src=0,tp_dst=0,flags(key)),in_port(1),skb_mark(0/0),eth(src=00:11:22:33:44:55,dst=00:23:20:00:00:01),eth_type(0x0800),ipv4(src=169.254.1.0/0.0.0.0,dst=169.254.1.1/0.0.0.0,proto=17/0xff,tos=0/0,ttl=255/0,frag=no),udp(src=49152/0,dst=3784/0xffff)' -generate], [0], [stdout])
 # check that the packet should be handled as normal packet.
 AT_CHECK([tail -1 stdout], [0],[dnl
 Datapath actions: 100
@@ -238,7 +247,7 @@ Datapath actions: 100
 
 # set the tunnel key to 0.
 AT_CHECK([ovs-vsctl set interface p1 options:key=0])
-AT_CHECK([ovs-appctl ofproto/trace ovs-dummy 'tunnel(tun_id=0x0,src=2.2.2.2,dst=2.2.2.1,tos=0x0,ttl=64,flags(key)),in_port(1),skb_mark(0/0),eth(src=00:11:22:33:44:55,dst=00:23:20:00:00:01),eth_type(0x0800),ipv4(src=169.254.1.0/0.0.0.0,dst=169.254.1.1/0.0.0.0,proto=17/0xff,tos=0/0,ttl=255/0,frag=no/0xff),udp(src=49152/0,dst=3784/0xffff)' -generate], [0], [stdout])
+AT_CHECK([ovs-appctl ofproto/trace ovs-dummy 'tunnel(tun_id=0x0,src=2.2.2.2,dst=2.2.2.1,tos=0x0,ttl=64,tp_src=0,tp_dst=0,flags(key)),in_port(1),skb_mark(0/0),eth(src=00:11:22:33:44:55,dst=00:23:20:00:00:01),eth_type(0x0800),ipv4(src=169.254.1.0/0.0.0.0,dst=169.254.1.1/0.0.0.0,proto=17/0xff,tos=0/0,ttl=255/0,frag=no),udp(src=49152/0,dst=3784/0xffff)' -generate], [0], [stdout])
 # check that the packet should be handled as BFD packet.
 AT_CHECK([tail -2 stdout], [0], [dnl
 This flow is handled by the userspace slow path because it:
@@ -255,201 +264,76 @@ OVS_VSWITCHD_START([add-br br1 -- set bridge br1 datapath-type=dummy -- \
                     options:peer=p0 ofport_request=2 -- \
                     add-port br0 p0 -- set Interface p0 type=patch \
                     options:peer=p1 ofport_request=1 -- \
-                    set Interface p0 bfd:enable=true bfd:min_tx=300 bfd:min_rx=300 bfd:decay_min_rx=3000 -- \
+                    set Interface p0 bfd:enable=true bfd:min_tx=300 bfd:min_rx=300 -- \
                     set Interface p1 bfd:enable=true bfd:min_tx=500 bfd:min_rx=500])
 
 ovs-appctl time/stop
-for i in `seq 0 1`; do ovs-appctl time/warp 500; done
-
-# figuring out which port initiates the bfd session is important,
-# since this whole unit test is based on exact timing sequence.
-# for example, if p0 starts the bfd session, the p0 should have gone
-# [up] now, and it will decay after 3000ms. if p1 starts the bfd
-# session, we should wait for another 1000ms for p0 to go [up], and
-# then 3000ms for it to decay.
-
-# check which port sends the first bfd control packet.
-if [ ovs-appctl bfd/show p0 | grep "Remote Session State: init" ]
-then
-# if p0 sends first, it should have gone up already.
-    BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [init], [No Diagnostic])
-else
-# if p1 sends first, wait 1000ms for p0 to go up.
-    BFD_CHECK([p0], [false], [false], [none], [init], [No Diagnostic], [none], [down], [No Diagnostic])
-    for i in `seq 0 1`; do ovs-appctl time/warp 500; done
-fi
 
+# wait for a while to stablize everything.
+ovs-appctl time/warp 10000 500
+BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
+BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
+BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
+BFD_CHECK_RX([p0], [500ms], [300ms], [500ms])
 
 # Test-1 BFD decay: decay to decay_min_rx
+AT_CHECK([ovs-vsctl set interface p0 bfd:decay_min_rx=3000])
 # bfd:decay_min_rx is set to 3000ms after the local state of p0 goes up,
-# so for the first 2500ms, there should be no change.
-for i in `seq 0 4`; do ovs-appctl time/warp 500; done
-BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
+# so for the first 2000ms, there should be no change.
+ovs-appctl time/warp 2000 500
 BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
 BFD_CHECK_RX([p0], [500ms], [300ms], [500ms])
 
-# advance the clock by 500ms.
-ovs-appctl time/warp 500
-# now at 3000ms, min_rx should decay to 3000ms and there should be
-# poll sequence flags.
-BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [final], [up], [No Diagnostic])
-BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [poll], [up], [No Diagnostic])
+# advance the clock by 5000ms.
+ovs-appctl time/warp 5000 500
+# now, min_rx should decay to 3000ms.
 BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
 BFD_CHECK_RX([p0], [3000ms], [3000ms], [500ms])
 
-# since the tx_min of p0 is still 500ms, after 500ms from decay,
-# the control message will be sent from p0 to p1, and p1 'flag'
-# will go back to none.
-ovs-appctl time/warp 500
-BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
-
-# the rx_min of p0 is 3000ms now, and p1 will send next control message
-# 3000ms after decay. so, advance clock by 2500ms to make that happen.
-for i in `seq 0 4`; do ovs-appctl time/warp 500; done
+# advance clock by 5000ms and check the flags are all 'none'.
+ovs-appctl time/warp 5000 500
 BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
+BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
 BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
 BFD_CHECK_RX([p0], [3000ms], [3000ms], [500ms])
 # End of Test-1 ###############################################################
 
 
-# Test-2 BFD decay: go back to cfg_min_rx when there is traffic
-# receive packet at 1/100ms rate for 3000ms.
-for i in `seq 0 30`
+# Test-2 BFD decay: go back to min_rx when there is traffic
+# receive packet at 1/100ms rate for 5000ms.
+for i in `seq 0 49`
 do
     ovs-appctl time/warp 100
     AT_CHECK([ovs-ofctl packet-out br1 3 2  "90e2ba01475000101856b2e80806000108000604000100101856b2e80202020300000000000002020202"],
              [0], [stdout], [])
 done
 # after a decay interval (3000ms), the p0 min_rx will go back to
-# cfg_min_rx. there should be poll sequence flags.
-BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [final], [up], [No Diagnostic])
-BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [poll], [up], [No Diagnostic])
-BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
-BFD_CHECK_RX([p0], [500ms], [300ms], [500ms])
-
-# 500ms later, both direction will send control messages,
-# and their 'flag' will go back to none.
-ovs-appctl time/warp 500
-BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
-BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
+# min_rx.
 BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
 BFD_CHECK_RX([p0], [500ms], [300ms], [500ms])
 # End of Test-2 ###############################################################
 
 
-# Test-3 BFD decay: go back to cfg_min_rx when decay_min_rx is changed
-# advance the clock by 2500ms to 3000m after restore of
-# min_rx. p0 is decayed, and there should be the poll sequence flags.
-for i in `seq 0 4`; do ovs-appctl time/warp 500; done
-BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [final], [up], [No Diagnostic])
-BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [poll], [up], [No Diagnostic])
-BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
-BFD_CHECK_RX([p0], [3000ms], [3000ms], [500ms])
-
-# advance the clock, to make 'flag' go back to none.
-for i in `seq 0 5`; do ovs-appctl time/warp 500; done
+# Test-3 BFD decay: set decay_min_rx to 1000ms.
+# this should firstly reset the min_rx and then re-decay to 1000ms.
+AT_CHECK([ovs-vsctl set Interface p0 bfd:decay_min_rx=1000])
+# advance the clock by 10000ms, decay should have happened.
+ovs-appctl time/warp 10000 500
 BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
 BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
-
-# change decay_min_rx to 1000ms.
-# for decay_min_rx < 2000ms, the decay detection time is set to 2000ms.
-# this should firstly reset the min_rx and start poll sequence.
-AT_CHECK([ovs-vsctl set Interface p0 bfd:decay_min_rx=1000])
-BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [final], [up], [No Diagnostic])
-BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [poll], [up], [No Diagnostic])
-BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
-BFD_CHECK_RX([p0], [500ms], [300ms], [500ms])
-
-# for the following 1500ms, there should be no decay,
-# since the decay_detect_time is set to 2000ms.
-for i in `seq 0 2`
-do
-    ovs-appctl time/warp 500
-    BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
-    BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
-    BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
-    BFD_CHECK_RX([p0], [500ms], [300ms], [500ms])
-done
-
-ovs-appctl time/warp 500
-# at 2000ms, decay should happen and there should be the poll sequence flags.
-BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [final], [up], [No Diagnostic])
-BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [poll], [up], [No Diagnostic])
 BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
 BFD_CHECK_RX([p0], [1000ms], [1000ms], [500ms])
-# advance the clock, so 'flag' go back to none.
-for i in `seq 0 4`; do ovs-appctl time/warp 500; done
 # End of Test-3 ###############################################################
 
 
-# Test-4 BFD decay: set min_rx to 800ms.
-# this should firstly reset the min_rx and then re-decay to 1000ms.
-AT_CHECK([ovs-vsctl set Interface p0 bfd:min_rx=800])
-BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [final], [up], [No Diagnostic])
-BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [poll], [up], [No Diagnostic])
-BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
-BFD_CHECK_RX([p0], [800ms], [800ms], [500ms])
-
-# for the following 1600ms, there should be no decay,
-# since the decay detection time is set to 2000ms.
-for i in `seq 0 1`
-do
-    ovs-appctl time/warp 800
-    BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
-    BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
-    BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
-    BFD_CHECK_RX([p0], [800ms], [800ms], [500ms])
-done
-
-ovs-appctl time/warp 400
-# at 2000ms, decay should happen and there should be the poll sequence flags.
-BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [final], [up], [No Diagnostic])
-BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [poll], [up], [No Diagnostic])
-BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
-BFD_CHECK_RX([p0], [1000ms], [1000ms], [500ms])
-# advance the clock, so 'flag' go back to none.
-for i in `seq 0 4`; do ovs-appctl time/warp 500; done
-# End of Test-4 ###############################################################
-
-
-# Test-5 BFD decay: set min_rx to 300ms and decay_min_rx to 5000ms together.
-AT_CHECK([ovs-vsctl set Interface p0 bfd:min_rx=300 bfd:decay_min_rx=5000])
-BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [final], [up], [No Diagnostic])
-BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [poll], [up], [No Diagnostic])
-BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
-BFD_CHECK_RX([p0], [500ms], [300ms], [500ms])
-
-# for decay_min_rx > 2000ms, the decay detection time is set to
-# decay_min_rx (5000ms).
-# for the following 4500ms, there should be no decay,
-# since the decay detection time is set to 5000ms.
-for i in `seq 0 8`
-do
-    ovs-appctl time/warp 500
-    BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
-    BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
-    BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
-    BFD_CHECK_RX([p0], [500ms], [300ms], [500ms])
-done
-
-ovs-appctl time/warp 500
-# at 5000ms, decay should happen and there should be the poll sequence flags.
-BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [final], [up], [No Diagnostic])
-BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [poll], [up], [No Diagnostic])
-BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
-BFD_CHECK_RX([p0], [5000ms], [5000ms], [500ms])
-# advance the clock, to make 'flag' go back to none.
-for i in `seq 0 9`; do ovs-appctl time/warp 500; done
-# End of Test-5 ###############################################################
-
-
-# Test-6 BFD decay: set decay_min_rx to 0 to disable bfd decay.
+# Test-4 BFD decay: set decay_min_rx to 0 to disable bfd decay.
 AT_CHECK([ovs-vsctl set Interface p0 bfd:decay_min_rx=0])
-# min_rx is reset, and there should be the poll sequence flags.
-BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [final], [up], [No Diagnostic])
-BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [poll], [up], [No Diagnostic])
+# advance the clock by 5000ms.
+ovs-appctl time/warp 10000 500
+# min_rx is reset.
 BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
 BFD_CHECK_RX([p0], [500ms], [300ms], [500ms])
+
 for i in `seq 0 20`
 do
     ovs-appctl time/warp 500
@@ -458,20 +342,20 @@ do
     BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
     BFD_CHECK_RX([p0], [500ms], [300ms], [500ms])
 done
-# End of Test-6 ################################################################
+# End of Test-4 ################################################################
 
 
-# Test-7 BFD decay: rmt_min_tx is greater than decay_min_rx
+# Test-5 BFD decay: rmt_min_tx is greater than decay_min_rx
 AT_CHECK([ovs-vsctl set Interface p0 bfd:decay_min_rx=3000 -- set interface p1 bfd:min_tx=5000])
-# there will be poll sequences from both sides. and it is hard to determine the
-# order. so just skip 10000ms and check the RX/TX. at that time, p0 should be in decay already.
-for i in `seq 0 19`; do ovs-appctl time/warp 500; done
+# advance the clock by 10000ms to stable everything.
+ovs-appctl time/warp 10000 500
 BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
 BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
+# p0 rx should show 5000ms even if it is in decay.
 BFD_CHECK_TX([p0], [500ms], [300ms], [5000ms])
 BFD_CHECK_RX([p0], [5000ms], [3000ms], [500ms])
 # then, there should be no change of status,
-for i in `seq 0 9`
+for i in `seq 0 19`
 do
     ovs-appctl time/warp 500
     BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
@@ -481,49 +365,47 @@ do
 done
 # reset the p1's min_tx to 500ms.
 AT_CHECK([ovs-vsctl set Interface p1 bfd:min_tx=500])
-# check the poll sequence. since p0 has been in decay, now the RX will show 3000ms.
-BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [final], [up], [No Diagnostic])
-BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [poll], [up], [No Diagnostic])
+# advance the clock by 20000ms to stable everything.
+# since p0 has been in decay, now the RX will show 3000ms.
+ovs-appctl time/warp 20000 500
 BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
 BFD_CHECK_RX([p0], [3000ms], [3000ms], [500ms])
-# advance the clock by 3000ms, at that time, p1 will send the control packets.
-# then there will be no poll flags.
-for i in `seq 0 5`; do ovs-appctl time/warp 500; done
-BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
-BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
-BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
-BFD_CHECK_RX([p0], [3000ms], [3000ms], [500ms])
-# End of Test-7 ###############################################################
+# End of Test-5 ###############################################################
 
 
-# Test-8 BFD decay: state up->down->up.
+# Test-6 BFD decay: state up->down->up.
 # turn bfd off on p1
 AT_CHECK([ovs-vsctl set Interface p1 bfd:enable=false])
 
-# check the state change of bfd on p0. After 9000 ms (3 min_rx intervals)
-for i in `seq 0 8`; do ovs-appctl time/warp 1000; done
+# advance the clock by 15000ms to stable everything.
+ovs-appctl time/warp 15000 1000
 BFD_CHECK([p0], [false], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
 BFD_CHECK_TX([p0], [1000ms], [1000ms], [0ms])
 BFD_CHECK_RX([p0], [300ms], [300ms], [1ms])
 
 # resume the bfd on p1. the bfd should not go to decay mode direclty.
 AT_CHECK([ovs-vsctl set Interface p1 bfd:enable=true])
-for i in `seq 0 3`; do ovs-appctl time/warp 500; done
+ovs-appctl time/warp 1500 500
 BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
 BFD_CHECK_RX([p0], [500ms], [300ms], [500ms])
 
-# since the decay_min_rx is still 3000ms, so after 3000ms, there should be the decay.
-for i in `seq 0 5`; do ovs-appctl time/warp 500; done
+# since the decay_min_rx is still 3000ms, so after 5000ms, p0 should have decayed.
+ovs-appctl time/warp 5000 500
 BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
 BFD_CHECK_RX([p0], [3000ms], [3000ms], [500ms])
-# End of Test-8 ################################################################
+# End of Test-6 ################################################################
 
 OVS_VSWITCHD_STOP
 AT_CLEANUP
 
 # Tests below are for bfd forwarding_if_rx feature.
-# forwarding_if_rx Test1: bfd is enabled on one end of link.
-AT_SETUP([bfd - bfd forwarding_if_rx 1])
+
+# forwarding_if_rx Test1
+# Test1 tests the case when bfd is only enabled on one end of the link.
+# Under this situation, the forwarding flag should always be false, even
+# though there is data packet received, since there is no bfd control
+# packet received during the demand_rx_bfd interval.
+AT_SETUP([bfd - bfd forwarding_if_rx - bfd on one side])
 OVS_VSWITCHD_START([add-br br1 -- set bridge br1 datapath-type=dummy -- \
                     add-port br1 p1 -- set Interface p1 type=patch \
                     options:peer=p0 ofport_request=2 -- \
@@ -549,48 +431,26 @@ do
     BFD_CHECK([p0], [false], [false], [none], [down], [No Diagnostic], [none], [down], [No Diagnostic])
 done
 
-# receive one packet.
-AT_CHECK([ovs-ofctl packet-out br1 3 2  "90e2ba01475000101856b2e80806000108000604000100101856b2e80202020300000000000002020202"],
-             [0], [stdout], [])
-for i in `seq 0 14`
-do
-    ovs-appctl time/warp 100
-    # the forwarding flag should be true, since there is data received.
-    BFD_CHECK([p0], [true], [false], [none], [down], [No Diagnostic], [none], [down], [No Diagnostic])
-    BFD_CHECK_TX([p0], [1000ms], [1000ms], [0ms])
-    BFD_CHECK_RX([p0], [500ms], [500ms], [1ms])
-done
-
-# Stop sending packets for 1000ms.
-for i in `seq 0 9`; do ovs-appctl time/warp 100; done
-BFD_CHECK([p0], [false], [false], [none], [down], [No Diagnostic], [none], [down], [No Diagnostic])
-BFD_CHECK_TX([p0], [1000ms], [1000ms], [0ms])
-BFD_CHECK_RX([p0], [500ms], [500ms], [1ms])
-
-# receive packet at 1/100ms rate for 1000ms.
-for i in `seq 0 9`
+# receive packet at 1/100ms rate for 2000ms.
+for i in `seq 0 19`
 do
     ovs-appctl time/warp 100
     AT_CHECK([ovs-ofctl packet-out br1 3 2  "90e2ba01475000101856b2e80806000108000604000100101856b2e80202020300000000000002020202"],
              [0], [stdout], [])
 done
-# the forwarding flag should be true, since there is data received.
-BFD_CHECK([p0], [true], [false], [none], [down], [No Diagnostic], [none], [down], [No Diagnostic])
-BFD_CHECK_TX([p0], [1000ms], [1000ms], [0ms])
-BFD_CHECK_RX([p0], [500ms], [500ms], [1ms])
-
-# reset bfd forwarding_if_rx.
-AT_CHECK([ovs-vsctl set Interface p0 bfd:forwarding_if_rx=false], [0])
-# forwarding flag should turn to false since the STATE is DOWN.
+# the forwarding flag should be false, due to the demand_rx_bfd.
 BFD_CHECK([p0], [false], [false], [none], [down], [No Diagnostic], [none], [down], [No Diagnostic])
-BFD_CHECK_TX([p0], [1000ms], [1000ms], [0ms])
-BFD_CHECK_RX([p0], [500ms], [500ms], [1ms])
 
 AT_CHECK([ovs-vsctl del-br br1], [0], [ignore])
+OVS_VSWITCHD_STOP
 AT_CLEANUP
 
-# forwarding_if_rx Test2: bfd is enabled on both ends of link.
-AT_SETUP([bfd - bfd forwarding_if_rx 2])
+
+# forwarding_if_rx Test2
+# Test2 is for testing that the enable of forwarding_if_rx will not
+# affect the normal bfd communication.  bfd is enabled on both ends of
+# the link.
+AT_SETUP([bfd - bfd forwarding_if_rx - bfd on both sides])
 OVS_VSWITCHD_START([add-br br1 -- set bridge br1 datapath-type=dummy -- \
                     add-port br1 p1 -- set Interface p1 type=patch \
                     options:peer=p0 ofport_request=2 -- \
@@ -602,7 +462,7 @@ OVS_VSWITCHD_START([add-br br1 -- set bridge br1 datapath-type=dummy -- \
 
 ovs-appctl time/stop
 # advance the clock, to stablize the states.
-for i in `seq 0 9`; do ovs-appctl time/warp 500; done
+ovs-appctl time/warp 5000 500
 
 # enable forwarding_if_rx.
 AT_CHECK([ovs-vsctl set Interface p0 bfd:forwarding_if_rx=true], [0])
@@ -623,7 +483,7 @@ for i in `seq 0 1`
 do
     ovs-appctl time/warp 500
     BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
-    for i in `seq 0 5`
+    for i in `seq 0 4`
     do
         AT_CHECK([ovs-ofctl packet-out br1 3 2  "90e2ba01475000101856b2e80806000108000604000100101856b2e80202020300000000000002020202"],
                  [0], [stdout], [])
@@ -635,37 +495,28 @@ done
 ovs-appctl time/warp 500
 BFD_CHECK([p0], [true], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
 
-# receive packet at 1/100ms rate for 1000ms.
-for i in `seq 0 9`
-do
-    AT_CHECK([ovs-ofctl packet-out br1 3 2  "90e2ba01475000101856b2e80806000108000604000100101856b2e80202020300000000000002020202"],
-             [0], [stdout], [])
-    ovs-appctl time/warp 100
-    # the forwarding flag should always be true during this time.
-    BFD_CHECK([p0], [true], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
-done
-
 # reset bfd forwarding_if_rx.
 AT_CHECK([ovs-vsctl set Interface p0 bfd:forwarding_if_rx=false], [0])
 # forwarding flag should turn to false since the STATE is DOWN.
 BFD_CHECK([p0], [false], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
-BFD_CHECK_TX([p0], [1000ms], [1000ms], [0ms])
-BFD_CHECK_RX([p0], [500ms], [500ms], [1ms])
 
 # re-enable bfd on the other end. the states should be up.
 AT_CHECK([ovs-vsctl set Interface p1 bfd:enable=true bfd:min_tx=300 bfd:min_rx=300])
 # advance the clock, to stablize the states.
-for i in `seq 0 9`; do ovs-appctl time/warp 500; done
+ovs-appctl time/warp 5000 500
 BFD_CHECK([p0], [true], [false], [none], [up], [Control Detection Time Expired], [none], [up], [No Diagnostic])
 BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [Control Detection Time Expired])
 BFD_CHECK_TX([p0], [500ms], [500ms], [300ms])
 BFD_CHECK_RX([p0], [500ms], [500ms], [300ms])
 
 AT_CHECK([ovs-vsctl del-br br1], [0], [ignore])
+OVS_VSWITCHD_STOP
 AT_CLEANUP
 
-# forwarding_if_rx Test3: bfd is enabled on both ends of link and decay is enabled.
-AT_SETUP([bfd - bfd forwarding_if_rx 3])
+# forwarding_if_rx Test3
+# Test3 is for testing that the enable of forwarding_if_rx will not
+# affect the bfd decay feature.  bfd is enabled on both ends of the link.
+AT_SETUP([bfd - bfd forwarding_if_rx - with bfd decay])
 OVS_VSWITCHD_START([add-br br1 -- set bridge br1 datapath-type=dummy -- \
                     add-port br1 p1 -- set Interface p1 type=patch \
                     options:peer=p0 ofport_request=2 -- \
@@ -676,7 +527,7 @@ OVS_VSWITCHD_START([add-br br1 -- set bridge br1 datapath-type=dummy -- \
 
 ovs-appctl time/stop
 # advance the clock, to stablize the states.
-for i in `seq 0 19`; do ovs-appctl time/warp 500; done
+ovs-appctl time/warp 10000 500
 BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
 BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
 BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
@@ -693,42 +544,27 @@ do
     BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
 done
 
-# reconfigure the decay_min_rx to 1000ms. check the poll sequence.
+# reconfigure the decay_min_rx to 1000ms.
 AT_CHECK([ovs-vsctl set interface p0 bfd:decay_min_rx=1000])
-BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [final], [up], [No Diagnostic])
-BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [poll], [up], [No Diagnostic])
-BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
-BFD_CHECK_RX([p0], [500ms], [300ms], [500ms])
-
-# wait for 2000ms to decay.
-for i in `seq 0 3`; do ovs-appctl time/warp 500; done
-BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [final], [up], [No Diagnostic])
-BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [poll], [up], [No Diagnostic])
-BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
-BFD_CHECK_RX([p0], [1000ms], [1000ms], [500ms])
 
-# wait for 1000ms, so that the flags will go back to none.
-for i in `seq 0 1`; do ovs-appctl time/warp 500; done
+# wait for 5000ms to decay.
+ovs-appctl time/warp 5000 500
 BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
-BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
 BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
 BFD_CHECK_RX([p0], [1000ms], [1000ms], [500ms])
 
 # stop the bfd on one side.
 AT_CHECK([ovs-vsctl set Interface p1 bfd:enable=false], [0])
-# for within 2500ms, the detection timer is not out.
-# there is no change to status.
-for i in `seq 0 4`
+
+# advance clock by 4000ms, while receiving packets.
+# the STATE should go DOWN, due to Control Detection Time Expired.
+# but forwarding flag should be still true.
+for i in `seq 0 7`
 do
     ovs-appctl time/warp 500
-    BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
     AT_CHECK([ovs-ofctl packet-out br1 3 2  "90e2ba01475000101856b2e80806000108000604000100101856b2e80202020300000000000002020202"],
              [0], [stdout], [])
 done
-
-# at 3000ms, the STATE should go DOWN, due to Control Detection Time Expired.
-# but forwarding flag should be still true.
-ovs-appctl time/warp 500
 BFD_CHECK([p0], [true], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
 
 # receive packet at 1/100ms rate for 1000ms.
@@ -741,32 +577,220 @@ do
     BFD_CHECK([p0], [true], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
 done
 
-# stop receiving for 2000ms.
-for i in `seq 0 19`; do ovs-appctl time/warp 100; done
+# stop receiving for 5000ms.
+ovs-appctl time/warp 5000 100
 BFD_CHECK([p0], [false], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
 
 # reset bfd forwarding_if_rx.
 AT_CHECK([ovs-vsctl set Interface p0 bfd:forwarding_if_rx=false])
-# forwarding flag should turn to false since the STATE is DOWN.
 BFD_CHECK([p0], [false], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
-BFD_CHECK_TX([p0], [1000ms], [1000ms], [0ms])
-BFD_CHECK_RX([p0], [300ms], [300ms], [1ms])
-
 # re-enable bfd forwarding_if_rx.
 AT_CHECK([ovs-vsctl set Interface p0 bfd:forwarding_if_rx=true])
-# there should be no change.
 BFD_CHECK([p0], [false], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
-BFD_CHECK_TX([p0], [1000ms], [1000ms], [0ms])
-BFD_CHECK_RX([p0], [300ms], [300ms], [1ms])
 
 # re-enable bfd on the other end. the states should be up.
 AT_CHECK([ovs-vsctl set Interface p1 bfd:enable=true bfd:min_tx=300 bfd:min_rx=300])
 # advance the clock, to stablize the states.
-for i in `seq 0 9`; do ovs-appctl time/warp 500; done
+ovs-appctl time/warp 10000 500
 BFD_CHECK([p0], [true], [false], [none], [up], [Control Detection Time Expired], [none], [up], [No Diagnostic])
 BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [Control Detection Time Expired])
 BFD_CHECK_TX([p0], [300ms], [300ms], [300ms])
 BFD_CHECK_RX([p0], [1000ms], [1000ms], [300ms])
 
 AT_CHECK([ovs-vsctl del-br br1], [0], [ignore])
-AT_CLEANUP
\ No newline at end of file
+OVS_VSWITCHD_STOP
+AT_CLEANUP
+
+# forwarding_if_rx Test4
+# Test4 is for testing the demand_rx_bfd feature.
+# bfd is enabled on both ends of the link.
+AT_SETUP([bfd - bfd forwarding_if_rx - demand_rx_bfd])
+OVS_VSWITCHD_START([add-br br1 -- set bridge br1 datapath-type=dummy -- \
+                    add-port br1 p1 -- set Interface p1 type=patch \
+                    options:peer=p0 ofport_request=2 -- \
+                    add-port br0 p0 -- set Interface p0 type=patch \
+                    options:peer=p1 ofport_request=1 -- \
+                    set Interface p0 bfd:enable=true bfd:min_tx=300 bfd:min_rx=300 bfd:forwarding_if_rx=true -- \
+                    set Interface p1 bfd:enable=true bfd:min_tx=500 bfd:min_rx=500])
+
+ovs-appctl time/stop
+# advance the clock, to stablize the states.
+ovs-appctl time/warp 10000 500
+BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
+BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
+BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
+
+# disable the bfd on p1.
+AT_CHECK([ovs-vsctl set Interface p1 bfd:enable=false], [0])
+
+# advance clock by 4000ms, while receiving packets.
+# the STATE should go DOWN, due to Control Detection Time Expired.
+# but forwarding flag should be still true.
+for i in `seq 0 7`
+do
+    ovs-appctl time/warp 500
+    AT_CHECK([ovs-ofctl packet-out br1 3 2  "90e2ba01475000101856b2e80806000108000604000100101856b2e80202020300000000000002020202"],
+             [0], [stdout], [])
+done
+BFD_CHECK([p0], [true], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
+
+# advance clock long enough to trigger the demand_bfd_rx interval
+# (100 * bfd->cfm_min_rx), forwarding flag should go down since there
+# is no bfd control packet received during the demand_rx_bfd.
+for i in `seq 0 120`
+do
+    ovs-appctl time/warp 300
+    AT_CHECK([ovs-ofctl packet-out br1 3 2  "90e2ba01475000101856b2e80806000108000604000100101856b2e80202020300000000000002020202"],
+             [0], [stdout], [])
+done
+BFD_CHECK([p0], [false], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
+
+# now enable the bfd on p1 again.
+AT_CHECK([ovs-vsctl set Interface p1 bfd:enable=true], [0])
+# advance clock by 5000ms.  and p1 and p0 should be all up.
+ovs-appctl time/warp 5000 500
+BFD_CHECK([p0], [true], [false], [none], [up], [Control Detection Time Expired], [none], [up], [No Diagnostic])
+BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [Control Detection Time Expired])
+BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
+
+# disable the bfd on p1 again.
+AT_CHECK([ovs-vsctl set Interface p1 bfd:enable=false], [0])
+# advance clock long enough to trigger the demand_rx_bfd,
+# forwarding flag should go down since there is no bfd control packet
+# received during the demand_rx_bfd.
+for i in `seq 0 120`
+do
+    ovs-appctl time/warp 300
+    AT_CHECK([ovs-ofctl packet-out br1 3 2  "90e2ba01475000101856b2e80806000108000604000100101856b2e80202020300000000000002020202"],
+             [0], [stdout], [])
+done
+BFD_CHECK([p0], [false], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
+
+AT_CHECK([ovs-vsctl del-br br1], [0], [ignore])
+OVS_VSWITCHD_STOP
+AT_CLEANUP
+
+# test bfd:flap_count.
+# This test contains three part:
+# part 1. tests the flap_count on normal bfd monitored link.
+# part 2. tests the flap_count when forwarding override is used.
+# part 3. tests the flap_count when forwarding_if_rx is enabled.
+AT_SETUP([bfd - flap_count])
+#Create 2 bridges connected by patch ports and enable bfd
+OVS_VSWITCHD_START([add-br br1 -- \
+                    set bridge br1 datapath-type=dummy \
+                    other-config:hwaddr=aa:55:aa:56:00:00 -- \
+                    add-port br1 p1 -- set Interface p1 type=patch \
+                    options:peer=p0 ofport_request=2 -- \
+                    add-port br0 p0 -- set Interface p0 type=patch \
+                    options:peer=p1 ofport_request=1 -- \
+                    set Interface p0 bfd:enable=true bfd:min_tx=100 bfd:min_rx=100 -- \
+                    set Interface p1 bfd:enable=true bfd:min_tx=100 bfd:min_rx=100])
+
+ovs-appctl time/stop
+# Disable the stats update to prevent the race between ovsdb updating
+# stats and ovs-vsctl cmd closing the jsonrpc session.
+AT_CHECK([ovs-vsctl set Open_vSwitch . other_config:stats-update-interval=50000000])
+
+# Part-1 wait for a while to stablize bfd.
+ovs-appctl time/warp 10100 100
+BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
+BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
+BFD_CHECK_TX([p0], [100ms], [100ms], [100ms])
+BFD_CHECK_RX([p0], [100ms], [100ms], [100ms])
+# both p0 and p1 should have flap_count = "1". since down->up.
+BFD_VSCTL_LIST_IFACE([p0], ["s/^.*flap_count=\(.*\), forwarding.*$/\1/p"], ["1"])
+BFD_VSCTL_LIST_IFACE([p1], ["s/^.*flap_count=\(.*\), forwarding.*$/\1/p"], ["1"])
+
+# turn bfd on p1 off, should increment the bfd:flap_count on p0.
+AT_CHECK([ovs-vsctl set interface p1 bfd:enable=false])
+ovs-appctl time/warp 5000 100
+BFD_CHECK([p0], [false], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
+BFD_VSCTL_LIST_IFACE([p0], ["s/^.*flap_count=\(.*\), forwarding.*$/\1/p"], ["2"])
+AT_CHECK([ovs-vsctl list interface p1 | sed -n "s/^.*flap_count=\(.*\), forwarding.*$/\1/p"])
+
+# turn bfd on p1 on again, should increment the bfd:flap_count on p0.
+# p1 should still have flap_count = "1", since it is reset.
+AT_CHECK([ovs-vsctl set interface p1 bfd:enable=true])
+ovs-appctl time/warp 5000 100
+BFD_VSCTL_LIST_IFACE([p0], ["s/^.*flap_count=\(.*\), forwarding.*$/\1/p"], ["3"])
+BFD_VSCTL_LIST_IFACE([p1], ["s/^.*flap_count=\(.*\), forwarding.*$/\1/p"], ["1"])
+
+
+# Part-2 now turn on the forwarding_override.
+AT_CHECK([ovs-appctl bfd/set-forwarding p0 true], [0], [dnl
+OK
+])
+
+# turn bfd on p1 off, should not increment the bfd:flap_count on p0, since forwarding_override is on.
+AT_CHECK([ovs-vsctl set interface p1 bfd:enable=false])
+ovs-appctl time/warp 5000 100
+BFD_CHECK([p0], [true], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
+BFD_VSCTL_LIST_IFACE([p0], ["s/^.*flap_count=\(.*\), forwarding.*$/\1/p"], ["3"])
+AT_CHECK([ovs-vsctl list interface p1 | sed -n "s/^.*flap_count=\(.*\), forwarding.*$/\1/p"])
+
+# turn bfd on p1 on again, should not increment the bfd:flap_count on p0, since forwarding override is on.
+# p1 should still have flap_count = "1", since it is reset.
+AT_CHECK([ovs-vsctl set interface p1 bfd:enable=true])
+ovs-appctl time/warp 5000 100
+BFD_VSCTL_LIST_IFACE([p0], ["s/^.*flap_count=\(.*\), forwarding.*$/\1/p"], ["3"])
+BFD_VSCTL_LIST_IFACE([p1], ["s/^.*flap_count=\(.*\), forwarding.*$/\1/p"], ["1"])
+
+# turn the forwarding_override back to normal.
+AT_CHECK([ovs-appctl bfd/set-forwarding p0 normal], [0], [dnl
+OK
+])
+
+# turn bfd on p1 off and on, should increment the bfd:flap_count on p0.
+AT_CHECK([ovs-vsctl set interface p1 bfd:enable=false])
+ovs-appctl time/warp 5000 100
+AT_CHECK([ovs-vsctl set interface p1 bfd:enable=true])
+ovs-appctl time/warp 5000 100
+BFD_VSCTL_LIST_IFACE([p0], ["s/^.*flap_count=\(.*\), forwarding.*$/\1/p"], ["5"])
+BFD_VSCTL_LIST_IFACE([p1], ["s/^.*flap_count=\(.*\), forwarding.*$/\1/p"], ["1"])
+
+# Part-3 now turn on forwarding_if_rx.
+AT_CHECK([ovs-vsctl set Interface p0 bfd:forwarding_if_rx=true], [0])
+ovs-appctl time/warp 1100 100
+# disable the bfd on p1.
+AT_CHECK([ovs-vsctl set Interface p1 bfd:enable=false], [0])
+
+# advance clock by 4000ms, while receiving packets.
+# the STATE should go DOWN, due to Control Detection Time Expired.
+# but forwarding flag should be true.
+for i in `seq 0 39`
+do
+    ovs-appctl time/warp 100
+    AT_CHECK([ovs-ofctl packet-out br1 3 2 "90e2ba01475000101856b2e80806000108000604000100101856b2e80202020300000000000002020202"],
+             [0], [stdout], [])
+done
+BFD_CHECK([p0], [true], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
+# flap_count should remain unchanged.
+BFD_VSCTL_LIST_IFACE([p0], ["s/^.*flap_count=\(.*\), forwarding.*$/\1/p"], ["5"])
+
+# stop the traffic for more than 100 * bfd->cfm_min_rx ms, the forwarding flag of p0 should turn false.
+# and there should be the increment of flap_count.
+ovs-appctl time/warp 12100 100
+BFD_CHECK([p0], [false], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
+BFD_VSCTL_LIST_IFACE([p0], ["s/^.*flap_count=\(.*\), forwarding.*$/\1/p"], ["6"])
+
+# advance clock by 4000ms, and resume the traffic.
+for i in `seq 0 39`
+do
+    ovs-appctl time/warp 100
+    AT_CHECK([ovs-ofctl packet-out br1 3 2 "90e2ba01475000101856b2e80806000108000604000100101856b2e80202020300000000000002020202"],
+             [0], [stdout], [])
+done
+# forwarding should be false, since there is still no bfd control packet received.
+BFD_CHECK([p0], [false], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
+BFD_VSCTL_LIST_IFACE([p0], ["s/^.*flap_count=\(.*\), forwarding.*$/\1/p"], ["6"])
+
+# turn on the bfd on p1.
+AT_CHECK([ovs-vsctl set interface p1 bfd:enable=true])
+ovs-appctl time/warp 5000 100
+# even though there is no data traffic, since p1 bfd is on again, should increment the flap_count.
+BFD_VSCTL_LIST_IFACE([p0], ["s/^.*flap_count=\(.*\), forwarding.*$/\1/p"], ["7"])
+BFD_VSCTL_LIST_IFACE([p1], ["s/^.*flap_count=\(.*\), forwarding.*$/\1/p"], ["1"])
+
+OVS_VSWITCHD_STOP
+AT_CLEANUP