Gateway_less_Fwd: Ping from vhost to vlan sub-interface fails when sub interface VN is configured with IP Fabric provider network

Ping from vhost to vlan sub-interface fails when sub interface VN is configured with IP Fabric provider network.

Build
------
R4.1.0.0 Build 23 Ubuntu 14.04 Mitaka

Topology
—————
Control/config/analytics node :nodei15
Compute nodes : nodek11, nodec23 and nodeb3

Steps
———--
1. Create a vn1 (1.1.1.0/24) and vn2 (2.2.2.0/24) (vn2 is vlan sub-interface vn)
2. Bring up a VM from vn1 and configure vlan subinterface belonging to vn2.
3. Now, configure IP Fabric network as provider network over vn2
4. Now, ping vlan sub-interface (say 2.2.2.4) from vhost and ping fails.

ICMP echo request from vrouter is going with vlan tag and ICMP echo reply is getting received without any vlan tag and vrouter is dropping the reply.

Please see the log below:

root@nodek11:~# tcpdump -ne -i tap8588480b-7c
tcpdump: WARNING: tap8588480b-7c: no IPv4 address assigned
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on tap8588480b-7c, link-type EN10MB (Ethernet), capture size 65535 bytes
13:50:06.420111 00:00:5e:00:01:00 > 02:85:88:48:0b:7c, ethertype 802.1Q (0x8100), length 102: vlan 100, p 0, ethertype IPv4, 10.204.216.231 > 2.2.2.4: ICMP echo request, id 3703, seq 14, length 64
13:50:06.420265 02:85:88:48:0b:7c > 00:00:5e:00:01:00, ethertype IPv4 (0x0800), length 98: 2.2.2.4 > 10.204.216.231: ICMP echo reply, id 3703, seq 14, length 64

root@nodek11:~# flow --match 2.2.2.4
Flow table(size 80609280, entries 629760)

Entries: Created 1243 Added 1243 Deleted 2362 Changed 2365 Processed 1243 Used Overflow entries 0
(Created Flows/CPU: 52 104 66 60 65 80 63 53 0 0 2 0 0 1 1 0 594 13 16 13 14 9 15 22 0 0 0 0 0 0 0 0)(oflows 0)

Action:F=Forward, D=Drop N=NAT(S=SNAT, D=DNAT, Ps=SPAT, Pd=DPAT, L=Link Local Port)
 Other:K(nh)=Key_Nexthop, S(nh)=RPF_Nexthop
 Flags:E=Evicted, Ec=Evict Candidate, N=New Flow, M=Modified Dm=Delete Marked
TCP(r=reverse):S=SYN, F=FIN, R=RST, C=HalfClose, E=Established, D=Dead

Listing flows matching ([2.2.2.4]:*)

    Index Source:Port/Destination:Port Proto(V)
-----------------------------------------------------------------------------------
   223112<=>466388 2.2.2.4:3703 1 (0)
                         10.204.216.231:0
(Gen: 1, K(nh):40, Action:F, Flags:, QOS:-1, S(nh):40, Stats:0/0, SPort 65271,
 TTL 0, Sinfo 0.0.0.0)

   466388<=>223112 10.204.216.231:3703 1 (0)
                         2.2.2.4:0
(Gen: 1, K(nh):5, Action:F, Flags:, QOS:-1, S(nh):10, Stats:303/25452,
 SPort 62792, TTL 0, Sinfo 0.0.0.0)

root@nodek11:~# vif --list
Vrouter Interface Table

Flags: P=Policy, X=Cross Connect, S=Service Chain, Mr=Receive Mirror
       Mt=Transmit Mirror, Tc=Transmit Checksum Offload, L3=Layer 3, L2=Layer 2
       D=DHCP, Vp=Vhost Physical, Pr=Promiscuous, Vnt=Native Vlan Tagged
       Mnp=No MAC Proxy, Dpdk=DPDK PMD Interface, Rfl=Receive Filtering Offload, Mon=Interface is Monitored
       Uuf=Unknown Unicast Flood, Vof=VLAN insert/strip offload, Df=Drop New Flows, L=MAC Learning Enabled
       Proxy=MAC Requests Proxied Always, Er=Etree Root

vif0/0 OS: em1 (Speed 1000, Duplex 1)
            Type:Physical HWaddr:0c:c4:7a:32:0a:88 IPaddr:0.0.0.0
            Vrf:0 Flags:L3L2VpEr QOS:-1 Ref:6
            RX packets:25062 bytes:3738581 errors:0
            TX packets:7086 bytes:7703785 errors:0
            Drops:936

vif0/1 OS: vhost0
            Type:Host HWaddr:0c:c4:7a:32:0a:88 IPaddr:10.204.216.231
            Vrf:0 Flags:PL3DEr QOS:-1 Ref:7
            RX packets:7928 bytes:7745833 errors:0
            TX packets:25011 bytes:3678575 errors:0
            Drops:1

vif0/2 OS: pkt0
            Type:Agent HWaddr:00:00:5e:00:01:00 IPaddr:0.0.0.0
            Vrf:65535 Flags:L3Er QOS:-1 Ref:3
            RX packets:3605 bytes:439666 errors:0
            TX packets:19398 bytes:2130741 errors:0
            Drops:0

vif0/3 OS: tap6e46fb66-74
            Type:Virtual HWaddr:00:00:5e:00:01:00 IPaddr:10.10.10.3
            Vrf:0 Flags:PL3L2DProxyEr QOS:-1 Ref:5
            RX packets:308 bytes:17200 errors:0
            TX packets:348 bytes:16992 errors:0
            ISID: 0 Bmac: 02:6e:46:fb:66:74
            Drops:0

vif0/4 OS: tap22f31b71-d4
            Type:Virtual HWaddr:00:00:5e:00:01:00 IPaddr:20.20.20.3
            Vrf:0 Flags:PL3L2DProxyEr QOS:-1 Ref:5
            RX packets:1062 bytes:98742 errors:0
            TX packets:619 bytes:58998 errors:0
            Drops:461

vif0/5 OS: tap07bf94ac-94
            Type:Virtual HWaddr:00:00:5e:00:01:00 IPaddr:12.109.56.3
            Vrf:65535 Flags:L3DEr QOS:-1 Ref:1
            RX packets:0 bytes:0 errors:0
            TX packets:0 bytes:0 errors:0
            ISID: 0 Bmac: 02:07:bf:94:ac:94
            Drops:0

vif0/6 OS: tap34b7315f-d4
            Type:Virtual HWaddr:00:00:5e:00:01:00 IPaddr:10.10.10.6
            Vrf:0 Flags:PL3L2DProxyEr QOS:-1 Ref:5
            RX packets:1442 bytes:116598 errors:0
            TX packets:984 bytes:75928 errors:0
            ISID: 0 Bmac: 02:34:b7:31:5f:d4
            Drops:488

vif0/7 OS: tap9655fa51-5a
            Type:Virtual HWaddr:00:00:5e:00:01:00 IPaddr:10.10.10.8
            Vrf:0 Flags:PL3L2DProxyEr QOS:-1 Ref:5
            RX packets:1210 bytes:111208 errors:0
            TX packets:606 bytes:56752 errors:0
            Drops:626

vif0/8 OS: tap8588480b-7c
            Type:Virtual HWaddr:00:00:5e:00:01:00 IPaddr:1.1.1.4
            Vrf:5 Flags:PL3L2DEr QOS:-1 Ref:6
            RX packets:2094 bytes:215508 errors:0
            TX packets:1248 bytes:118448 errors:0
            Drops:2094

vif0/9 720be9c7-8da1-473e-a858-1f5ad43d6e1c Vlan(o/i)(,S): 100/100 Bridge Index: 0 Parent:vif0/8
            Type:Virtual(Vlan) HWaddr:00:00:5e:00:01:00 IPaddr:2.2.2.4
            Vrf:0 Flags:PL3L2DProxyEr QOS:-1 Ref:5
            RX packets:270 bytes:12420 errors:0
            TX packets:1442 bytes:131180 errors:0
            Drops:0

vif0/4350 OS: pkt3
            Type:Stats HWaddr:00:00:00:00:00:00 IPaddr:0.0.0.0
            Vrf:65535 Flags:L3L2 QOS:0 Ref:1
            RX packets:0 bytes:0 errors:0
            TX packets:0 bytes:0 errors:0
            Drops:0

vif0/4351 OS: pkt1
            Type:Stats HWaddr:00:00:00:00:00:00 IPaddr:0.0.0.0
            Vrf:65535 Flags:L3L2 QOS:0 Ref:1
            RX packets:0 bytes:0 errors:0
            TX packets:0 bytes:0 errors:0
            Drops:0

root@nodek11:~#

root@nodek11:~# ping 2.2.2.4
PING 2.2.2.4 (2.2.2.4) 56(84) bytes of data.

^C
--- 2.2.2.4 ping statistics ---
4 packets transmitted, 0 received, 100% packet loss, time 3024ms

root@nodek11:~#

VM
——
root@box:/home/tc# ifconfig -a
dummy0 Link encap:Ethernet HWaddr 52:9a:8c:8a:0a:13
          BROADCAST NOARP MTU:1500 Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)

eth0 Link encap:Ethernet HWaddr 02:85:88:48:0b:7c
          inet addr:1.1.1.4 Bcast:1.1.1.255 Mask:255.255.255.0
          inet6 addr: fe80::85:88ff:fe48:b7c/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:16654 errors:0 dropped:0 overruns:0 frame:0
          TX packets:16482 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:1573297 (1.5 MiB) TX bytes:1952536 (1.8 MiB)

eth0.100 Link encap:Ethernet HWaddr 02:85:88:48:0b:7c
          inet addr:2.2.2.4 Bcast:2.2.2.255 Mask:255.255.255.0
          inet6 addr: fe80::85:88ff:fe48:b7c/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:6431 errors:0 dropped:0 overruns:0 frame:0
          TX packets:5079 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:456794 (446.0 KiB) TX bytes:420512 (410.6 KiB)

ip_vti0 Link encap:IPIP Tunnel HWaddr
          NOARP MTU:1364 Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)

lo Link encap:Local Loopback
          inet addr:127.0.0.1 Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING MTU:65536 Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)

tunl0 Link encap:IPIP Tunnel HWaddr
          NOARP MTU:1480 Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)

root@box:/home/tc#