No Phoned Home event for machines on new switch interfaces

[majst01]

A BUG was discovered, when a leaf was reconfigured via ansible to add more interfaces for additional machines, but metal-core was not restarted, all newly allocated machines connected on these interfaces will never be reported as Phoned Home.

[robertvolkmann]

The lldp-syncd daemon in SONiC pushes all recently received LLDP packets into Redis. You can see this behavior at this link.

Instead of tracing LLDP packets directly, we could monitor the Redis database. This approach would resolve the issue on SONiC devices.

Example entry in APPL_DB:

$ hgetall LLDP_ENTRY_TABLE:Ethernet33
 1) "lldp_rem_port_id_subtype"
 2) "5"
 3) "lldp_rem_port_id"
 4) "lan1"
 5) "lldp_rem_port_desc"
 6) "lan1"
 7) "lldp_rem_chassis_id_subtype"
 8) "4"
 9) "lldp_rem_chassis_id"
10) "50:7c:6f:3e:8d:95"
11) "lldp_rem_sys_name"
12) "2937da00-6ae3-11ed-8000-3cecefa833f8"
13) "lldp_rem_sys_desc"
14) "provisioned since 2023-09-18T07:48:15Z"
15) "lldp_rem_man_addr"
16) ""
17) "lldp_rem_time_mark"
18) "4"
19) "lldp_rem_index"
20) "1273"
21) "lldp_rem_sys_cap_supported"
22) ""
23) "lldp_rem_sys_cap_enabled"
24) ""