Virtual Private LAN Service (VPLS) Management Information Base
Extracted elements (26)
MAC address association with VPLS entries uses a turnstile function via SNMP-CONTEXT-MAP-MIB rather than direct MIB linkage. This maps vacmContextName to dot1dBasePort and vplsConfigIndex, allowing access to MAC addresses in the BRIDGE-MIB without duplicating the MAC table in the VPLS MIB.
An entry in the vplsBgpConfigTable MUST be created by the agent for a VPLS service signaled using BGP.
An entry in the vplsConfigTable MUST exist for every VPLS service. This table holds generic parameters applicable to VPLS services signaled via LDP or BGP.
An entry in the vplsLdpConfigTable MUST be created by the agent for a VPLS service signaled using LDP.
At least one entry in the vplsPwBindTable MUST exist for each VPLS service, linking the service to one or more pseudowires defined in RFC 5601.
Changes to vplsConfigSignalingType are only allowed when vplsConfigRowStatus is in notInService(2) or notReady(3) states; it cannot be changed while the row is active(1).
For each VPLS service with auto-discovery enabled, an entry in the vplsBgpAdConfigTable MUST exist, and at least one entry in the vplsBgpRteTargetTable MUST exist.
The vplsConfigRowStatus object controls row lifecycle; all other objects MUST be set to valid values before it can be set to active(1). Setting it to destroy(6) SHALL delete all associated entries in vplsPwBindTable, vplsBgpRteTargetTable, and vplsBgpVETable.
Forwarding database utilization is monitored via vplsConfigFwdFullHighWatermark (default 95%) and vplsConfigFwdFullLowWatermark (default 90%), triggering vplsFwdFullAlarmRaised and vplsFwdFullAlarmCleared notifications respectively.
The VPLS-BGP-MIB defines vplsBgpConfigVERangeSize (Unsigned32 0..65535, default 0) specifying the VPLS Edge Identifier range size for label block advertisement. The VE ID occupies 2 octets in BGP NLRI per RFC 4761, limiting the range to 65535.
The VPLS-LDP-MIB defines vplsLdpConfigMacAddrWithdraw (TruthValue, default true) to enable/disable MAC address withdrawal per RFC 4762, and vplsLdpPwBindMacAddressLimit (Unsigned32, default 0 meaning unlimited) to cap learned and static MAC entries per PW binding.
The VPLS MIB is composed of three modules: VPLS-GENERIC-MIB for common parameters, VPLS-LDP-MIB for LDP-specific parameters (RFC 4762), and VPLS-BGP-MIB for BGP-specific parameters (RFC 4761). These modules are used in conjunction with PW-STD-MIB (RFC 5601).
The vplsBgpADConfigTable stores BGP auto-discovery parameters including vplsBgpADConfigRouteDistinguisher (OCTET STRING 0..256 per RFC 4364), vplsBgpADConfigVplsId (unique identifier for all VSIs in a VPLS), and vplsBgpADConfigPrefix (overrides loopback address in NLRI per RFC 6074).
The vplsBgpPwBindTable provides BGP-specific pseudowire binding information with vplsBgpPwBindLocalVEId and vplsBgpPwBindRemoteVEId (both read-only Unsigned32 1..65535), identifying the local and remote VEs associated with each pseudowire.
The vplsBgpRteTargetTable specifies Route Targets imported or exported by BGP during VPLS auto-discovery. Each entry has vplsBgpRteTargetRTType (import/export/both) and vplsBgpRteTargetRT (OCTET STRING 0..256), supporting hierarchical VPLS via multiple Route Targets per service.
The vplsBgpVETable associates VE IDs with VPLS service instances. Each entry includes vplsBgpVEId (Unsigned32 1..65535), vplsBgpVEName (SnmpAdminString), and vplsBgpVEPreference (Unsigned32 0..65535) for multihomed sites where the VE ID is reused.
The vplsConfigTable includes vplsConfigMacLearning (TruthValue, default true), vplsConfigDiscardUnknownDest (TruthValue, default false), and vplsConfigMacAging (TruthValue, default true) to control MAC address handling behavior.
The vplsConfigTable row includes vplsConfigIndex (Unsigned32, unique identifier), vplsConfigName (SnmpAdminString), vplsConfigAdminStatus (up/down/testing), vplsConfigSignalingType (ldp/bgp/none), vplsConfigMtu (64..9192, default 1518), and vplsConfigVpnId (IEEE 802-1990 VPN ID).
The vplsLdpPwBindMacTableFull notification is generated when the number of learned MAC addresses reaches the value in vplsLdpPwBindMacAddressLimit, carrying vplsConfigName and pwID as bound objects.
The vplsPwBindTable links VPLS instances to pseudowires. Each entry specifies vplsPwBindConfigType (manual or autodiscovery) and vplsPwBindType (mesh or spoke), both of which must be specified at row creation and cannot be changed while active.
Three SNMP notifications are defined in VPLS-GENERIC-MIB: vplsStatusChanged (admin or operational status change), vplsFwdFullAlarmRaised (forwarding DB above high watermark), and vplsFwdFullAlarmCleared (forwarding DB below low watermark).
vplsNotificationMaxRate (Unsigned32, default 0) controls the maximum notifications per second. A value of 0 means no throttling; implementations may drop or queue excess notifications when the rate is exceeded.
IANA assigned three OID values in the SMI Numbers registry: { transmission 274 } for VPLS-GENERIC-MIB, { transmission 275 } for VPLS-LDP-MIB, and { transmission 276 } for VPLS-BGP-MIB.
Implementations SHOULD provide SNMPv3 security features; implementations claiming SNMPv3 compliance MUST include full USM support with AES cipher (RFC 3826). Deployment of SNMP versions prior to SNMPv3 is NOT RECOMMENDED; SNMPv3 with cryptographic security is RECOMMENDED instead.
Read-write and read-create objects in vplsConfigTable, vplsPwBindTable, vplsBgpADConfigTable, vplsBgpRteTargetTable, vplsLdpPwBindTable, vplsLdpConfigTable, vplsBgpConfigTable, and vplsBgpVETable can disrupt VPLS services if improperly configured. SNMPv3 VACM and USM MUST be used with any v3 agent providing SET access to these tables.
Setting vplsNotificationMaxRate to a very high value can cause a notification storm that may disrupt network service. Readable MIB objects may expose sensitive topology information and should be protected with access controls and encryption even for GET and NOTIFY operations.