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Cisco Active Network Abstraction Technology Support and Information Model Reference Manual, 3.6.6
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Preface
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Introduction
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Internet Protocol
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Routing Protocols (BGP/OSPF)
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Ethernet (IEEE 802.3)
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Asynchronous Transfer Mode
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Frame Relay
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Point-to-Point Protocol and High-Level Data Link Control
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Layer 2 Tunnel Protocol
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Digital Subscriber Line
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Integrated Services Digital Network
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Physical Technologies
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Multiprotocol Label Switching
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Multiprotocol Label Switching Traffic Engineering
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Virtual Private Networks
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Pseudowire Emulation Edge to Edge
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Access Control Lists
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Bidirectional Forwarding Detection
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Internet Protocol Over Dense Wave Division Multiplexing
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Local Switching
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Physical Equipment
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Base Logical Components
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Common Components
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Cisco ANA VNE Topology
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Index
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Table Of Contents
Inventory and Information Model Objects (IMOs)
Virtual Routing Forwarding (VRF) Entity
Equivalent Cross Virtual Routing Entry
Vendor-Specific Inventory and IMOs
Virtual Private Networks
This chapter describes the level of support that Cisco ANA provides for Virtual Private Networks (VPNs), as follows:
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Inventory and Information Model Objects (IMOs)
Technology Description
VPN
BGP/MPLS VPNs, as defined in RFC 2547 and related drafts and standards, provide a Layer 3 VPN. With Layer 3 VPNs, each Provider Edge (PE) device acts like a set of virtual routers, one per VPN. The network provider configures the VPN membership of each PE router interface. In most cases, one port is used for multiple interfaces where each is associated with different VPNs. The port's view of the network is restricted to the VPNs of which it is a member, and it cannot address devices outside that environment. Conventional IP routing is the interface between Customer Edge (CE) and PE devices: Static routes can be provisioned on both the CE and PE, or for more complex scenarios, a routing protocol (such as RIP, OSPF or BGP) is run between CE and PE.
The network provider can also establish a suitable mesh of MPLS Label Switched Paths (LSPs) between all the PE routers that need to communicate. The PE devices qualify each external IP address that they learn with a per VPN identifier, and broadcast them to all other PE routers using an extended form of BGP depending on BGP connectivity. They also include an MPLS label that is specific to the destination route (or, in some implementations, the destination port). Through this process, the PE devices build up a complete map of the VPNs and destination labels. The PE routers then use this information to route the packets across the backbone network to the correct destination within the relevant VPN.
6VPE
6VPE (RFC 2547) permits IPv6 domains to communicate with each other over an IPv4 core network, without explicit tunnel setup, requiring only one IPv4 address per IPv6 domain. 6VPE operates much like a normal IPv4 MPLS VPN provider edge, but with the addition of IPv6 support within VRF. It lets service providers support IPv6 over operational IPv4 MPLS backbones without requiring dual-stacking within the MPLS core, representing a large cost savings over core re-engineering. Only PE equipment must be dual-stack, to support awareness of both IPv4 and IPv6 access devices. 6VPE provides logically separate routing table entries for VPN member devices.
VRF-Lite (Multi-VRF)
VRF-Liteis an application based on VRF that extends the concept of VRF to the customer-premises router. It supports multiple, overlapping, independent routing and forwarding tables per customer.
Any routing protocol supported by normal VRF can be used in a VRF-Lite CE implementation. The CE supports traffic separation between customer networks. As there is no MPLS functionality on the CE, no label exchange happens between the CE and PE.
Inventory and Information Model Objects (IMOs)
This section describes the following IMOs:
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Virtual Routing Forwarding (VRF) Entity
The Virtual Routing Forwarding (VRF) Entity object describes the routing and address resolution protocols independent forwarding component of a MPLS-BGP based VPN router. It is bound by its Logical Sons attribute to all the Network layer IP Interface objects among which it is routing IP Packets.
Table 14-1 Virtual Routing Forwarding (VRF) Entity (IVrf)
Virtual Routing Table
Array of Equivalent Routing Entries
IP Core
Configuration
Exported Route Targets
Array of route target identifiers
IP Core
Configuration
Imported Route Targets
Array of route target identifiers
IP Core
Configuration
AddressFamilies
List of the address families (IPv4, IPv6, or both)
IP Core
Configuration
Route Distinguisher
Route distinguisher
IP Core
Configuration
ARP Entity
Address Resolution Entity (ARP Entity) (see Internet Protocol)
IP Core
Configuration
Name
VRF name
IP Core
Configuration
Logical Sons
Array of all IP Interfaces among which this Virtual Routing Forwarding (VRF) Entity is routing IP packets
IP Core
N/A
Equivalent Routing Entry
The Equivalent Routing Entry and Virtual Routing Entry objects describe a routing table's entries. Each is an array of Virtual Routing Entries sharing a single IP Subnetwork destination.
Table 14-2 Equivalent Routing Entry (IRoutingEntries)
Routing Entries
Array of Virtual Routing Entries sharing a single destination
IP Core
Configuration
Virtual Routing Entry
Multi Protocol BGP Entity
The Multi Protocol BGP Entity object describes the BGP component of a MPLS-BGP based VPN router. It is bound by its Logical Sons attribute to all Virtual Routing Forwarding (VRF) Entity objects among which it is routing IP Packets.
Table 14-4 Multi Protocol BGP Entity (IMpBgp)
BGP Identifier
Border Gateway Protocol (BGP) identifier
IP Core
Configuration
Local Autonomous System
Local peer autonomous system
IP Core
Configuration
Cross Virtual Routing Table
IP Core
Configuration
BGP Neighbors
Array of BGP neighbor entries (see Routing Protocols (BGP/OSPF))
IP Core
Configuration
Logical Sons
Array of all Virtual Routing Forwarding (VRF) Entity objects among which this Multi Protocol BGP Entity is routing IP Packets
IP Core
N/A
Equivalent Cross Virtual Routing Entry
The Equivalent Cross Virtual Routing Entry and Cross Virtual Routing Entry objects describe the first dimension of a cross virtual routing table, as an array of Cross Virtual Routing Entry objects sharing a single Virtual Routing Forwarding (VRF) Entity destination.
Table 14-5 Equivalent Cross Virtual Routing Entry (ICrossVrf)
Virtual Routing Entries
Array of Cross Virtual Routing Entry objects sharing a single destination
IP Core
Configuration
Virtual Routing Entity Name
Virtual Routing Entity (VRF) name
IP Core
Configuration
Cross Virtual Routing Entry
Vendor-Specific Inventory and IMOs
There are no vendor-specific inventory or IMOs for this technology.
Network Topology
Cisco ANA discovers MPLS-BGP based Virtual Private (VPN) network topology by searching for the existence of the local Virtual Routing Forwarding (VRF) Entity's imported route targets in any remote side's VRF entity exported route targets.
Service Alarms
The following alarm is supported for this technology:
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For detailed information about alarms and correlation, see the Cisco Active Network Abstraction 3.6.6 User Guide.