SNMP: extend Cisco serial_number coverage and add Catalyst 1300/9200 sysobjectids

Adds entPhysicalSerialNum.67109120 as the primary ENTITY-MIB fallback for
Cisco devices that expose chassis data at the CBS350/Catalyst 1300 index,
and keeps entPhysicalSerialNum.1 as the secondary fallback.

- _cisco-catalyst.yaml: insert the .67109120 entry ahead of .1 in the
  serial_number symbols list so Catalyst 1300 and Cat 9400/9200 chassis
  (e.g. cisco_switch_c9407r) report a serial even when the legacy
  chassisSerialNumberString is absent.
- _cisco-metadata.yaml: add the same fallback chain so profiles that
  inherit it (cisco.yaml via _base_cisco -> _cisco-generic) gain
  serial_number metadata.
- cisco-sb.yaml: define serial_number with the same chain for CBS350
  devices that fall outside the cisco-catalyst inheritance tree.
- cisco-catalyst.yaml: add Catalyst 9200 (1.3.6.1.4.1.9.1.3079) and
  Catalyst 1300 (.3233, .3236) sysobjectids so those devices match the
  Catalyst profile.

Refs AGENT-15682.

Author: ian28223

snmp/datadog_checks/snmp/data/default_profiles/_cisco-catalyst.yaml

@@ -16,6 +16,10 @@ metadata:
           #   Cisco Systems WS-C6509.Cisco Catalyst Operating System Software, Version 5.5(8).Copyright (c) 1995-2001 by Cisco Systems.
           - OID: 1.3.6.1.4.1.9.5.1.2.19.0
             name: chassisSerialNumberString
+          # ENTITY-MIB: entPhysicalSerialNum at entPhysicalIndex 67109120 — Catalyst 1300 / CBS-derived chassis.
+          # Reference: https://www.cisco.com/c/en/us/support/docs/smb/switches/Cisco-Business-Switching/kmgmt3636-snmpv3-common-oids-cbs350.html
+          - OID: 1.3.6.1.2.1.47.1.1.1.1.11.67109120
+            name: entPhysicalSerialNum
           # ENTITY-MIB: entPhysicalSerialNum at entPhysicalIndex 1 — fallback when stack MIB data is missing.
           # Source: https://circitor.fr/Mibs/Html/ENTITY-MIB.php
           # Stacked members often use x000 indexes (1000, 2000, …); add more list entries if you need them.

snmp/datadog_checks/snmp/data/default_profiles/_cisco-metadata.yaml

@@ -5,6 +5,16 @@ metadata:
     fields:
       vendor:
         value: "cisco"
+      serial_number:
+        symbols:
+          # ENTITY-MIB: entPhysicalSerialNum at entPhysicalIndex 67109120 — Catalyst 1300 / CBS-derived chassis.
+          # Reference: https://www.cisco.com/c/en/us/support/docs/smb/switches/Cisco-Business-Switching/kmgmt3636-snmpv3-common-oids-cbs350.html
+          - OID: 1.3.6.1.2.1.47.1.1.1.1.11.67109120
+            name: entPhysicalSerialNum
+          # ENTITY-MIB: entPhysicalSerialNum at entPhysicalIndex 1 — common chassis index.
+          # Source: https://circitor.fr/Mibs/Html/ENTITY-MIB.php
+          - OID: 1.3.6.1.2.1.47.1.1.1.1.11.1
+            name: entPhysicalSerialNum
       version:
         symbol:
           OID: 1.3.6.1.2.1.1.1.0

snmp/datadog_checks/snmp/data/default_profiles/cisco-catalyst.yaml

@@ -463,3 +463,6 @@ sysobjectid:
   - 1.3.6.1.4.1.9.1.3023 # ciscoC1000FE48T4GL
   - 1.3.6.1.4.1.9.1.3024 # ciscoC1000FE48P4GL
   - 1.3.6.1.4.1.9.1.3069 # ciscoC8500L8S4X
+  - 1.3.6.1.4.1.9.1.3079 # ciscoC9200CX12P2X2G
+  - 1.3.6.1.4.1.9.1.3233 # ciscoC130024P4G
+  - 1.3.6.1.4.1.9.1.3236 # ciscoSwitch1300

snmp/datadog_checks/snmp/data/default_profiles/cisco-sb.yaml

@@ -10,6 +10,16 @@ metadata:
     fields:
       vendor:
         value: "cisco"
+      serial_number:
+        symbols:
+          # ENTITY-MIB: entPhysicalSerialNum at entPhysicalIndex 67109120 — CBS350 / Cisco Small Business chassis.
+          # Reference: https://www.cisco.com/c/en/us/support/docs/smb/switches/Cisco-Business-Switching/kmgmt3636-snmpv3-common-oids-cbs350.html
+          - OID: 1.3.6.1.2.1.47.1.1.1.1.11.67109120
+            name: entPhysicalSerialNum
+          # ENTITY-MIB: entPhysicalSerialNum at entPhysicalIndex 1 — common chassis index.
+          # Source: https://circitor.fr/Mibs/Html/ENTITY-MIB.php
+          - OID: 1.3.6.1.2.1.47.1.1.1.1.11.1
+            name: entPhysicalSerialNum
 metrics:
   - MIB: CISCOSB-rndMng
     symbol: