EVPN VXLAN: CB Build 4.0.1.0-81: DHCP request from BMS getting discarded in TSN

[chhandak]

With EVPN VXLAN solution DHCP packet from BMS is getting discarded in vrouter.
Not seen any DHCP packet entry as per agent introspect http://10.87.69.1:8085/Snh_DhcpInfo?

root@5b11s14:~# vxlan --dump
VXLAN Table

 VNID NextHop
----------------
      4 13
root@5b11s14:~#
root@5b11s14:~#
root@5b11s14:~# nh --get 13
Id:13 Type:Vrf_Translate Fmly:AF_BRIDGE Rid:0 Ref_cnt:3 Vrf:2
              Flags:Valid, Etree Root,
              Vrf:2

root@5b11s14:~# rt --dump 2 --family bridge
Flags: L=Label Valid, Df=DHCP flood, Mm=Mac Moved, L2c=L2 Evpn Control Word, N=New Entry, Ec=EvpnControlProcessing
vRouter bridge table 0/2
Index DestMac Flags Label/VNID Nexthop Stats
31264 0:0:5e:0:1:0 Df - 3 0
40992 90:e2:ba:c4:2e:6c L 4 20 0 >> BMS
112924 ff:ff:ff:ff:ff:ff LDf 4 22 63
119856 90:e2:ba:a7:30:cd Df - 3 0
root@5b11s14:~#
root@5b11s14:~#
root@5b11s14:~# nh --get 22
Id:22 Type:Composite Fmly:AF_BRIDGE Rid:0 Ref_cnt:4 Vrf:2
              Flags:Valid, Multicast, L2, Etree Root,
              Sub NH(label): 18(0) 21(0) 16(0)

Id:18 Type:Composite Fmly: AF_INET Rid:0 Ref_cnt:2 Vrf:2
              Flags:Valid, Tor, Etree Root,
              Sub NH(label):

Id:21 Type:Composite Fmly: AF_INET Rid:0 Ref_cnt:2 Vrf:2
              Flags:Valid, Evpn, Etree Root,
              Sub NH(label): 20(4)

Id:20 Type:Tunnel Fmly: AF_INET Rid:0 Ref_cnt:3 Vrf:0
              Flags:Valid, Vxlan, Etree Root,
              Oif:0 Len:14 Data:84 b5 9c c8 00 00 90 e2 ba a7 30 cd 08 00
              Sip:172.16.180.101 Dip:172.16.2.1 >>>>>>>>>>>>TOR is present in composite nexthop

Id:16 Type:Composite Fmly: AF_INET Rid:0 Ref_cnt:2 Vrf:2
              Flags:Valid, Fabric, Etree Root,
              Sub NH(label): 15(4610)

Id:15 Type:Tunnel Fmly: AF_INET Rid:0 Ref_cnt:2 Vrf:0
              Flags:Valid, MPLSoGRE, Etree Root,
              Oif:0 Len:14 Data:90 e2 ba b1 ff ac 90 e2 ba a7 30 cd 08 00
              Sip:172.16.180.101 Dip:172.16.180.103

root@5b11s14:~# tcpdump -ni p514p2 udp port 4789
tcpdump: WARNING: p514p2: no IPv4 address assigned
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on p514p2, link-type EN10MB (Ethernet), capture size 65535 bytes
16:50:16.025378 IP 172.16.2.1.37796 > 172.16.180.101.4789: VXLAN, flags [I] (0x08), vni 4
IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 90:e2:ba:c4:2e:6c, length 300
16:50:19.784652 IP 172.16.2.1.37796 > 172.16.180.101.4789: VXLAN, flags [I] (0x08), vni 4
IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 90:e2:ba:c4:2e:6c, length 300
16:50:22.453280 IP 172.16.2.1.37796 > 172.16.180.101.4789: VXLAN, flags [I] (0x08), vni 4
IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 90:e2:ba:c4:2e:6c, length 300

root@5b11s14:~# dropstats | grep -v " 0$"

Discards 69
Cloned Original 69

root@5b11s14:~# dropstats | grep -v " 0$"

Discards 71 >>>> Discard count is increasing
Cloned Original 71

[Hari Prasad Killi (haripk)]

In /etc/contrail/contrail-vrouter-agent.conf
agent_mode = tsn

In case of EVPN TSN, this should be
agent_mode = tsn-no-forwarding

Also, tsn_servers is not present in the agent.conf file. Is this provisioned using Ansible & SM or set manually ? If the former, we have to debug provisioning.

Tried restarting vrouter-agent with this changed. But this time, the TOR IP didnt come in the TOR composite.