All MIBs › CISCO-SWITCH-CGMP-MIB
Organization: Cisco Systems, Inc
Last Updated: 1998-05-07
Category: Cisco Devices, VLAN and Bridging
Description: Manages Cisco Group Management Protocol (CGMP) for hardware-accelerated multicast snooping on Cisco LAN switches.
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What Is CISCO-SWITCH-CGMP-MIB?
CISCO-SWITCH-CGMP-MIB manages the switch-side implementation of Cisco Group Management Protocol (CGMP), which lets a Layer 2 switch snoop router-originated CGMP messages to hardware-accelerate IP multicast group forwarding without full IGMP snooping. It belongs to Cisco's LAN switching/multicast feature area. The data it exposes is configuration and state for multicast forwarding: global CGMP enable/fast-leave settings, router hold-time, and a table of learned multicast routers per VLAN with their MAC addresses and row status. For monitoring, it is used to confirm the switch's multicast-snooping software feature is enabled and correctly tracking upstream multicast routers per VLAN, a software/feature-status check rather than a hardware-health metric. It typically works alongside standard bridge/VLAN MIBs and the router-side CGMP/IGMP implementation for full multicast-path visibility, and it is deployed on Cisco Catalyst Layer 2 switches in networks using CGMP for multicast traffic optimization, where CISCO-SWITCH-CGMP-MIB SNMP monitoring confirms multicast router adjacency is maintained per VLAN.
IPNetwork Monitor allows you to monitor SNMP objects defined in CISCO-SWITCH-CGMP-MIB. Use the built-in SNMP Monitoring Browser to explore available variables, view their current values and descriptions, and select the objects you want to monitor. You can then create SNMP monitors, configure thresholds, and receive alerts when monitored values change.
Supported Devices
- Cisco Catalyst Layer 2 switches
Monitoring Examples
An operator checks sCgmpEnable and sCgmpFastLeaveEnable to confirm CGMP snooping and fast-leave are active switch-wide, then polls sCgmpRouterTable/sCgmpRouterEntry, keyed by sCgmpRouterVlanIndex, to see the sCgmpRouterMacAddress of the multicast router learned on each VLAN. If a VLAN expected to have an active multicast router shows no entry in sCgmpRouterTable, it indicates the switch has lost CGMP adjacency, meaning multicast traffic may fall back to flooding. sCgmpRouterHoldTime governs how long a learned router entry is retained before aging out.
What Can Be Monitored
- CGMP enable/fast-leave status
- learned multicast router per VLAN
- multicast router MAC address
- router hold-time/aging
- CGMP row status per VLAN
Imported Objects
From BRIDGE-MIB
| dot1dBasePort | OBJECT-TYPE |
From CISCO-SMI
| ciscoMgmt | OBJECT-IDENTITY |
From SNMPv2-CONF
| MODULE-COMPLIANCE | |
| OBJECT-GROUP |
From SNMPv2-SMI
| MODULE-IDENTITY | |
| OBJECT-TYPE |
From SNMPv2-TC
| MacAddress | |
| RowStatus | |
| TEXTUAL-CONVENTION |
OIDs
RFC description
Switch-side Cisco Group Management Protocol MIB for Layer 2 Switch devices; enables multicast traffic management via CGMP.
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