[snmp | lldp] table is no present in SNMP facts

[vadymhlushko-mlnx]

Description

Steps to reproduce the issue:

1. Run the snmp/test_snmp_lldp.py

Describe the results you received:

        # Check if lldpLocManAddrTable is present
        for k in ['lldpLocManAddrLen', \
                   'lldpLocManAddrIfSubtype', \
                   'lldpLocManAddrIfId', \
                   'lldpLocManAddrOID']:
>           assert snmp_facts['snmp_lldp'][k]
E           KeyError: 'lldpLocManAddrLen'

snmp/test_snmp_lldp.py:56: KeyError

Describe the results you expected:

The test snmp/test_snmp_lldp.py should pass

Additional information you deem important:

**Output of `show version`:**

root@r-tigon-04:/home/admin# show version

SONiC Software Version: SONiC.201911.62-01871c46
Distribution: Debian 9.13
Kernel: 4.9.0-11-2-amd64
Build commit: 01871c46
Build date: Sun Jan 24 11:21:05 UTC 2021
Built by: sw-r2d2-bot@r-build-sonic-ci02

Platform: x86_64-mlnx_msn4600c-r0
HwSKU: ACS-MSN4600C
ASIC: mellanox
Serial Number: MT2017X29667
Uptime: 08:44:45 up 30 min,  1 user,  load average: 1.17, 1.42, 1.29

Docker images:
REPOSITORY                    TAG                  IMAGE ID            SIZE
docker-syncd-mlnx             201911.62-01871c46   23300e55e92e        399MB
docker-syncd-mlnx             latest               23300e55e92e        399MB
docker-sonic-telemetry        201911.62-01871c46   7390b0f20ba1        353MB
docker-sonic-telemetry        latest               7390b0f20ba1        353MB
docker-router-advertiser      201911.62-01871c46   054822d074e8        290MB
docker-router-advertiser      latest               054822d074e8        290MB
docker-platform-monitor       201911.62-01871c46   9d365eac9ed3        666MB
docker-platform-monitor       latest               9d365eac9ed3        666MB
docker-fpm-frr                201911.62-01871c46   3e213e60e5fe        335MB
docker-fpm-frr                latest               3e213e60e5fe        335MB
docker-teamd                  201911.62-01871c46   18b2fae1c452        315MB
docker-teamd                  latest               18b2fae1c452        315MB
docker-lldp-sv2               201911.62-01871c46   d194a1fc3734        312MB
docker-lldp-sv2               latest               d194a1fc3734        312MB
docker-dhcp-relay             201911.62-01871c46   91e5109501d8        300MB
docker-dhcp-relay             latest               91e5109501d8        300MB
docker-database               201911.62-01871c46   606201313cb2        290MB
docker-database               latest               606201313cb2        290MB
docker-snmp-sv2               201911.62-01871c46   a728ad0a214b        351MB
docker-snmp-sv2               latest               a728ad0a214b        351MB
docker-orchagent              201911.62-01871c46   e9b579c5380c        333MB
docker-orchagent              latest               e9b579c5380c        333MB
docker-sflow                  201911.62-01871c46   1b594cf0a595        315MB
docker-sflow                  latest               1b594cf0a595        315MB
docker-nat                    201911.62-01871c46   72705bb65c59        317MB
docker-nat                    latest               72705bb65c59        317MB
docker-sonic-mgmt-framework   201911.62-01871c46   48bcd90c9b33        430MB
docker-sonic-mgmt-framework   latest               48bcd90c9b33        430MB

[vadymhlushko-mlnx]

show techsupport
sonic_dump_r-tigon-04_20210126_083642.tar.gz

[liat-grozovik]

@yxieca can you please review ? this is seen on 201911 as well

[yxieca]

@vadymhlushko-mlnx from the dump, I don't see any lldp neighbor other than from eth0. Is this expected?

Can you paste the output of lldpshow from sonic?

To further analyzer the issue, I also need you to run a test with instrumented code:

this line: https://github.com/Azure/sonic-mgmt/blob/master/tests/snmp/test_snmp_lldp.py#L39 will not show up in output because pytest muted it. But if you could change it to

import logging
import json
logging.warning(json.dumps(snmp_facts, indent=4))

and send me the contents of snmp_facts, that would be really helpful.

[vadymhlushko-mlnx]

@yxieca

$ lldpshow command output:

root@r-tigon-04:/home/admin# lldpshow
Capability codes: (R) Router, (B) Bridge, (O) Other
LocalPort    RemoteDevice             RemotePortID    Capability    RemotePortDescr
-----------  -----------------------  --------------  ------------  -----------------
Ethernet128  ARISTA01T1               Ethernet1       BR
Ethernet130  ARISTA02T1               Ethernet1       BR
Ethernet136  ARISTA03T1               Ethernet1       BR
Ethernet138  ARISTA04T1               Ethernet1       BR
eth0         MTR-F-1-S-LAB-R3-9-SW01  2               B             2
--------------------------------------------------
Total entries displayed:  5

Output of snmp_facts var:
snmp_lldp_output.txt

[yxieca]

These 4 entries should have been populated here: https://github.com/Azure/sonic-snmpagent/blob/3885f193be05099659808092d22c5f69407cdda4/src/sonic_ax_impl/mibs/ieee802_1ab.py#L710

They are all local management information. Missing them is an image issue.

[vadymhlushko-mlnx]

These 4 entries should have been populated here: https://github.com/Azure/sonic-snmpagent/blob/3885f193be05099659808092d22c5f69407cdda4/src/sonic_ax_impl/mibs/ieee802_1ab.py#L710

They are all local management information. Missing them is an image issue.

Okay, so, how to fix it?

[yxieca]

Let's move this issue to buildimage and have it triaged there.

[abdosi]

There are two issues here:

First the LLDP docker when setting the command "configure system ip management pattern" uses MGMT_INTERFACE.keys() which can be any order of v4 and v6 Management IP .

Second SNMP currently only handles v4 Management Address
https://github.com/Azure/sonicsnmpagent/blob/3885f193be05099659808092d22c5f69407cdda4/src/sonic_ax_impl/mibs/ieee802_1ab.py#L323

We are looking into fixing both so that we are consistent in assigning IP Address and SNMP should be able to handle v6 also.

[abdosi]

cherry-pick #5699 to 201911. This should fix this issue.
@vadymhlushko-mlnx can you re-verify and confirm ?

[vadymhlushko-mlnx]

cherry-pick #5699 to 201911. This should fix this issue.
@vadymhlushko-mlnx can you re-verify and confirm ?

The fix is working, the test - PASSED