[Sflow][BRCM] : Flow packets are not sampled by sflow

[chitra-raghavan]

Description
flow Packets are not sampled by Sflow and received by sflow collector. Only counter samples are received by Sflow collector.
This is verified in 201911 branch.

Steps to reproduce the issue:

1. Enable sflow on an interface , and assign ip address to interface.
2. Configure loopback as collector
3. From peer , send packets to interface .
4. Check if packets are sampled by sflow and sent to collector

Describe the results you received:
Packets are sent to interface Ethernet1. These flow packets are not sampled by the sflow . , only Counter samples are collected by the collector

root@sonic-s6100-07:~# show sflow interface
 
sFlow interface configurations
+-------------+---------------+-----------------+
| Interface   | Admin State   |   Sampling Rate |
+=============+===============+=================+
| Ethernet0   | up            |             512 |
+-------------+---------------+-----------------+
| Ethernet1   | up            |             512 |
+-------------+---------------+-----------------+
root@sonic-s6100-07:~# show sflow
 
sFlow Global Information:
  sFlow Admin State:          up
  sFlow Polling Interval:     10
  sFlow AgentID:              default
 
  1 Collectors configured:
	Name: loopback            IP addr: 127.0.0.1  UDP port: 6343
root@sonic-s6100-07:~#
 
 
 
root@sonic-s6100-07:~# show interface counters | grep Ethernet1
 Ethernet1        U   13,437  79.99 KB/s      0.00%         0         0         0        6    12.58 B/s      0.00%         0         0         0



root@sonic-s6100-07:~# sflowtool -l
CNTR,10.11.46.86,78,6,40000000000,0,3,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,77,6,40000000000,0,3,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,76,6,40000000000,0,3,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,75,6,40000000000,0,3,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,74,6,40000000000,0,0,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,73,6,40000000000,0,0,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,72,6,40000000000,0,0,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,70,6,40000000000,0,3,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,69,6,40000000000,0,3,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,67,6,40000000000,0,3,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,65,6,40000000000,0,3,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,61,6,40000000000,0,3,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,59,6,40000000000,0,3,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,58,6,40000000000,0,0,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,56,6,40000000000,0,0,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,55,6,40000000000,0,0,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,54,6,40000000000,0,3,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,53,6,40000000000,0,3,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,52,6,40000000000,0,3,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,51,6,40000000000,0,3,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,50,6,40000000000,0,3,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,49,6,40000000000,0,3,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,48,6,40000000000,0,3,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0
CNTR,10.11.46.86,47,6,40000000000,0,3,0,0,4294967295,4294967295,0,0,4294967295,0,0,4294967295,4294967295,0,0,0

Additional information you deem important (e.g. issue happens only occasionally):

**Output of `show version`:**
root@sonic-s6100-07:~# show ver

SONiC Software Version: SONiC.HEAD.31-055d7cd1
Distribution: Debian 9.12
Kernel: 4.9.0-11-2-amd64
Build commit: 055d7cd1
Build date: Mon Mar 16 20:46:35 UTC 2020
Built by: johnar@jenkins-worker-7

Platform: x86_64-dell_s6100_c2538-r0
HwSKU: Force10-S6100
ASIC: broadcom
Serial Number: 2G5ZZP2
Uptime: 05:00:08 up 5 min,  1 user,  load average: 3.67, 2.92, 1.40

Docker images:

Docker images:
REPOSITORY                    TAG                 IMAGE ID            SIZE
docker-syncd-brcm             HEAD.31-055d7cd1    31fb4b7a906b        430MB
docker-syncd-brcm             latest              31fb4b7a906b        430MB
docker-platform-monitor       HEAD.31-055d7cd1    035a869d4325        334MB
docker-platform-monitor       latest              035a869d4325        334MB
docker-router-advertiser      HEAD.31-055d7cd1    6d0a964549c5        283MB
docker-router-advertiser      latest              6d0a964549c5        283MB
docker-fpm-frr                HEAD.31-055d7cd1    579a525fa8a3        327MB
docker-fpm-frr                latest              579a525fa8a3        327MB
docker-sflow                  HEAD.31-055d7cd1    8dfcf4fddee0        307MB
docker-sflow                  latest              8dfcf4fddee0        307MB
docker-lldp-sv2               HEAD.31-055d7cd1    8d09bae23cb9        304MB
docker-lldp-sv2               latest              8d09bae23cb9        304MB
docker-orchagent              HEAD.31-055d7cd1    e630365d8d1f        325MB
docker-orchagent              latest              e630365d8d1f        325MB
docker-dhcp-relay             HEAD.31-055d7cd1    6972cb6f2aa4        293MB
docker-dhcp-relay             latest              6972cb6f2aa4        293MB
docker-database               HEAD.31-055d7cd1    91b6facd8e22        283MB
docker-database               latest              91b6f^Croot@sonic-s6100-07:~#

root@sonic-s6100-07:~#


**Attach debug file `sudo generate_dump`:**

```
(paste your output here)
```

[xinliu-seattle]

dgsudharsan and prince are discussing how to fix this.

[xinliu-seattle]

the change is under-going.