BGP/MPLS Layer 3 VPN Multicast Management Information Base
Extracted elements (22)
The MIB separates generic MVPN state (mvpnGenericTable) from BGP-MVPN-specific state (mvpnBgpTable) because the two C-multicast signaling methods (PIM-MVPN and BGP-MVPN) share most managed objects but differ in BGP-specific parameters such as extended communities, route advertisement throttles, and inter-site C-tree mode.
Two compliance levels are defined: mvpnModuleFullCompliance (all groups mandatory) and mvpnModuleReadOnlyCompliance (same groups but all read-write objects downgraded to read-only). The read-only compliance allows monitoring-only deployments without configuration capability, while BGP-specific groups are additionally mandatory only on systems supporting BGP-MVPN.
BGP-MPLS-LAYER3-VPN-MULTICAST-MIB is designed to be used in conjunction with MPLS-L3VPN-STD-MIB (RFC 4382) and IPMCAST-MIB (RFC 5132). Row pointers and shared index components (mplsL3VpnVrfName) link entries across these three MIB modules.
Several conceptual rows use multi-component OID indexes that can exceed 128 sub-identifiers when address strings are long (e.g., mvpnSpmsiEntry warns if mplsL3VpnVrfName + group addr + source addr exceeds 113 octets). Such rows cannot be accessed via SNMPv1, SNMPv2c, or SNMPv3.
For each entry in mvpnGenericTable, there MUST be a corresponding VRF entry in MPLS-L3VPN-STD-MIB (RFC 4382). This coupling ensures that every MVPN management entry is anchored to an existing VRF.
For mvpnMrouteCmcastSourceAddrType and mvpnMrouteNextHopSourceAddrType, if the value is not unknown(0), it MUST be the same as the corresponding group address type. A value of unknown(0) indicates a non-source-specific (*,G) entry.
In mvpnMrouteCmcastGroupAddr and mvpnMrouteCmcastSourceAddrs, address bits beyond the corresponding prefix length MUST be set to zero. This requirement also applies to the equivalent objects in mvpnMrouteNextHopTable.
mvpnSPTunnelLimit (Unsigned32, range 1..4294967295) sets the maximum number of selective provider tunnels allowed for a particular MVPN on the PE, per RFC 6513 Section 13. This is a read-write scalar, configurable by the operator.
BGP-MPLS-LAYER3-VPN-MULTICAST-MIB defines seven conceptual tables: mvpnGenericTable, mvpnBgpTable, mvpnPmsiTable, mvpnSpmsiTable, mvpnAdvtStatsTable, mvpnMrouteTable, and mvpnMrouteNextHopTable. Together they support monitoring and configuration of MVPN instances on a Provider Edge (PE) router for both PIM-MVPN and BGP-MVPN deployments.
mvpnAdvtStatsTable tracks per-MVPN, per-peer-PE advertisement statistics indexed by VRF name, advertisement type (intraAsIpmsi, interAsIpmsi, sPmsi), peer address type, and peer address. Counters include sent, received, received-with-error, malformed tunnel type, and malformed tunnel identifier, with a discontinuity timestamp.
mvpnBgpTable supplements mvpnGenericTable with BGP-MVPN-specific parameters: inter-site C-tree mode (rptSpt or sptOnly), VRF Route Import Extended Community, Source AS Extended Community, BGP message rate limit, and configurable upper bounds on S-PMSI A-D routes, Source Active A-D routes, and their respective generation frequencies.
mvpnGenericTable is indexed by mplsL3VpnVrfName and stores per-MVPN attributes including last action type (createdMvrf, deletedMvrf, modifiedMvrfIpmsiConfig, modifiedMvrfSpmsiConfig), C-multicast route protocol (PIM or BGP), UMH selection method, and customer site type. Each row corresponds to one MVPN instance on the PE.
mvpnMrouteNextHopTable stores per-next-hop forwarding information for each multicast route, indexed by (VRF name, group prefix, source prefix, outgoing ifIndex, next-hop address). Key fields include mvpnMrouteNextHopState (pruned or forwarding), expiry time, closest member hops (0–256), and per-next-hop octet/packet counters.
mvpnMrouteTable contains multicast routing entries per MVRF indexed by (VRF name, group address/prefix, source address/prefix). Columns include upstream neighbor, incoming interface, expiry time, routing/forwarding protocol, octet/packet counters (Counter64), TTL-dropped counters, a PMSI pointer, and local/remote replication counts.
mvpnMvrfActionTaken is the sole NOTIFICATION-TYPE defined in this MIB. It fires on any MVRF change on the PE and carries objects: mvpnGenMvrfCreationTime, mvpnGenMvrfLastAction, mvpnGenMvrfLastActionTime, mvpnGenCmcastRouteProtocol, mvpnGenUmhSelection, and mvpnGenCustomerSiteType.
mvpnPmsiEncapsulationType enumerates three encapsulations for PMSI packets: greIp(1) (GRE per RFC 2784), ipIp(2) (IP-in-IP per RFC 2003), and mpls(3) (MPLS per RFC 3032), as specified in RFC 6513 Section 12.1.
mvpnPmsiTable is indexed by mvpnPmsiTunnelIfIndex (equal to the ifIndex of the PMSI in ifTable) and stores PMSI attributes common to both I-PMSI and S-PMSI: Route Distinguisher, tunnel type (L2L3VpnMcastProviderTunnelType), pointer to the P-tunnel, PIM group address (for PIM-based tunnels), and encapsulation type (GRE, IP-in-IP, or MPLS).
mvpnSpmsiTable stores S-PMSI-specific information indexed by VRF name, C-multicast group address/prefix, and C-multicast source address/prefix. Each row includes a RowPointer (mvpnSpmsiPmsiPointer) linking to the corresponding generic PMSI entry in mvpnPmsiTable.
Three configurable BGP-MVPN scalar timers are defined: mvpnBgpCmcastRouteWithdrawalTimer (milliseconds, controls delay of C-multicast route withdrawal per RFC 6514 §16.1.1), mvpnBgpSrcSharedTreeJoinTimer (milliseconds, controls delay of Source/Shared Tree Join advertisements per RFC 6514 §16.1.2), and mvpnBgpMsgRateLimit (messages/second, caps BGP C-multicast message exchange rate).
IANA assigned OID { mib-2 243 } to the BGP-MPLS-LAYER3-VPN-MULTICAST-MIB module (mvpnMIB). This is the top-level OID under which all notifications, objects, and conformance information for this MIB are organized.
Section 4 addresses SNMP security for this MIB. Read-write objects (mvpnSPTunnelLimit, BGP timers and thresholds) can be used to misconfigure MVPN behavior, potentially causing service disruption; implementations should apply appropriate access controls such as SNMPv3 with authentication and privacy. Read-only objects expose sensitive topology information (peer addresses, tunnel types, route details) that could aid network reconnaissance.
mvpnMrouteNextHopState has two states: pruned(1) and forwarding(2). In the pruned state, mvpnMrouteNextHopExpiryTime counts down the remaining prune lifetime; upon expiry the entry transitions to forwarding(2). In forwarding state, the expiry time indicates when the entry will be aged out.