Description of problem:
When we modify an existing logical switch port row in the north db, to change MAC address of a VM, changes are propagated to the OVN-controller on the OVN host, we can also see some openflow rules being created with the new MAC address, but a VM (with the new MAC address) is unable to receive IP address from DHCP. When we revert the address change, and set the original MAC address, VM is able to get IP.

Log output below shows that they are missing openflow rules for the changed MAC address: 00:1a:4a:16:20:61, when comparing it to the old MAC address: 00:1a:4a:16:20:31.

ovn-controller.log (host of VM):
2017-01-30T14:02:30.381Z|00054|binding|INFO|Claiming lport 3ef3d175-f1fa-47cb-9a5a-2bb6b1efa860 for this chassis.
2017-01-30T14:02:30.381Z|00055|binding|INFO|Claiming 00:1a:4a:16:20:31 dynamic
2017-01-30T14:03:18.484Z|00056|binding|INFO|Releasing lport 3ef3d175-f1fa-47cb-9a5a-2bb6b1efa860 from this chassis.
2017-01-30T14:03:18.484Z|00057|binding|INFO|Releasing 00:1a:4a:16:20:31 dynamic
2017-01-30T14:03:25.831Z|00058|binding|INFO|Claiming lport 3ef3d175-f1fa-47cb-9a5a-2bb6b1efa860 for this chassis.
2017-01-30T14:03:25.831Z|00059|binding|INFO|Claiming 00:1a:4a:16:20:61 dynamic


openflow rules (host of VM):

# ovs-ofctl dump-flows br-int | grep 00:1a:4a:16:20:61
 cookie=0x0, duration=1772.475s, table=29, n_packets=0, n_bytes=0, idle_age=1772, priority=50,metadata=0x1,dl_dst=00:1a:4a:16:20:61 actions=load:0x1->NXM_NX_REG15[],resubmit(,32)

# ovs-ofctl dump-flows br-int | grep 00:1a:4a:16:20:31
 cookie=0x0, duration=1775.567s, table=26, n_packets=0, n_bytes=0, idle_age=1775, priority=50,arp,metadata=0x1,arp_tpa=172.16.0.2,arp_op=1 actions=move:NXM_OF_ETH_SRC[]->NXM_OF_ETH_DST[],mod_dl_src:00:1a:4a:16:20:31,load:0x2->NXM_OF_ARP_OP[],move:NXM_NX_ARP_SHA[]->NXM_NX_ARP_THA[],load:0x1a4a162031->NXM_NX_ARP_SHA[],move:NXM_OF_ARP_SPA[]->NXM_OF_ARP_TPA[],load:0xac100002->NXM_OF_ARP_SPA[],move:NXM_NX_REG14[]->NXM_NX_REG15[],load:0x1->NXM_NX_REG10[0],resubmit(,32)
 cookie=0x0, duration=1775.577s, table=27, n_packets=0, n_bytes=0, idle_age=1775, priority=100,udp,reg14=0x1,metadata=0x1,dl_src=00:1a:4a:16:20:31,nw_src=0.0.0.0,nw_dst=255.255.255.255,tp_src=68,tp_dst=67 actions=controller(userdata=00.00.00.02.00.00.00.00.00.01.de.10.00.00.00.63.ac.10.00.02.01.04.ff.ff.ff.00.03.04.ac.10.00.fe.36.04.ac.10.00.00.33.04.00.01.51.80.06.04.08.08.08.08,pause),resubmit(,28)
 cookie=0x0, duration=1775.577s, table=28, n_packets=0, n_bytes=0, idle_age=1775, priority=100,udp,reg0=0x8/0x8,reg14=0x1,metadata=0x1,dl_src=00:1a:4a:16:20:31,nw_src=0.0.0.0,nw_dst=255.255.255.255,tp_src=68,tp_dst=67 actions=move:NXM_OF_ETH_SRC[]->NXM_OF_ETH_DST[],mod_dl_src:02:00:00:00:00:00,mod_nw_dst:172.16.0.2,mod_nw_src:172.16.0.0,mod_tp_src:67,mod_tp_dst:68,move:NXM_NX_REG14[]->NXM_NX_REG15[],load:0x1->NXM_NX_REG10[0],resubmit(,32)

Version-Release number of selected component (if applicable):
openvswitch 2.6.90

How reproducible:
100%

Steps to Reproduce:

1. Create OVN switch, and make sure that there are settings for subnet, so VM's attached to the switch will able to get DHCP.
1. Create a VM with vNIC that has MAC address: 00:1a:4a:16:20:31
2. Hot-unplug the vNIC from the switch, and change the MAC address to: 00:1a:4a:16:20:61.
3. Use dhclient on VM to get IP.

Actual results:
VM doesn't receive IP.

Expected results:
VM should receive IP.

Additional info: