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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)
Link Aggregation Group Port Entry
Data Link Aggregation Container
Spanning Tree Protocol Service
Multiple Spanning Tree Protocol Service
Multiple Spanning Tree Protocol Properties
Spanning Tree Protocol Instance Information
Multiple Spanning Tree Protocol Instance Information
Per-VLAN Spanning Tree Protocol Instance Information
Rapid Spanning Tree Protocol Instance Information
Spanning Tree Protocol Port Information
Multiple Spanning Tree Protocol Port Information
Vendor-Specific Inventory and IMOs
Ethernet (IEEE 802.3)
This chapter describes the level of support that Cisco ANA provides for Ethernet, as follows:
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Inventory and Information Model Objects (IMOs)
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Technology Description
Ethernet
Ethernet refers to the family of LAN products covered by the IEEE 802.3 standard that defines the carrier sense multiple access collision detect (CSMA/CD) protocol. Four data rates are currently defined for operation over optical fiber and twisted-pair cables: 10Base-T Ethernet (10 Mb/s), Fast Ethernet (100 Mb/s), Gigabit Ethernet (1000 Mb/s) and 10-Gigabit Ethernet (10 Gb/s).
The IEEE 802.3 standard provides MAC (Layer 2) Addressing, Duplexing, Differential Services, and Flow Control attributes, and various physical (Layer 1) definitions, with Media, Clocking, and Speed attributes. It also provides a LAG (also known as Ethernet Channel) definition for providing both higher link capacity and availability.
LAG
A Link Aggregation Group (LAG) is a group of two or more network links bundled together to appear as a single link based on the IEEE 802.3ad standard. For instance, bundling two 100-Mb/s network interfaces into a single link creates one 200-Mb/s link. A LAG may include two or more network cards and two or more cables, but the software sees the link as one logical link.
A LAG provides capacity increase, load balancing, and higher link availability, which prevents the failure of any single component link leading to a disruption of the communications between the interconnected devices.
Metro Ethernet
A Metro Ethernet is a computer network based on the Ethernet standards covering a metropolitan area. It is commonly used as a metropolitan access network (MAN) to connect subscribers and businesses to a WAN, such as the Internet. Large businesses can also use Metro Ethernet to connect branch offices to their intranets.
A typical service-provider Metro Ethernet network is a collection of Layer 2 or Layer 3 switches or routers, connected through optical fiber, with a ring, hub-and-spoke (star), full mesh, or partial mesh topology. The network will also have a hierarchy; core, distribution, and access. The core in most cases is an existing IP/MPLS backbone.
Ethernet on the MAN can be used as pure Ethernet, Ethernet over SDH, Ethernet over MPLS, or Ethernet over dense wavelength-division multiplexing (DWDM). Pure Ethernet deployments are cheap but less reliable and scalable, and thus are usually limited to small-scale or experimental deployments. SDH deployments are useful when there is an existing SDH infrastructure already in place, its main shortcoming being the loss of flexibility in bandwidth management due to the rigid hierarchy imposed by the SDH network. MPLS deployments are costly but highly reliable and scalable, and are typically used by large service providers.
See also:
Spanning Tree Protocol (STP)
STP is a Layer 2 link management protocol that provides path redundancy while preventing undesirable loops in the network. For a Layer 2 Ethernet network to function properly, only one active path can exist between any two devices.
STP defines a tree with a root bridge and a loop-free path from the root to all network devices in the Layer 2 network. STP forces redundant data paths into a standby (blocked) state. If a network segment in the spanning tree fails and a redundant path exists, the STP algorithm recalculates the spanning tree topology and activates the standby path.
Cisco ANA STP modeling supports devices that use the following STP variants:
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QinQ (IEEE802.1ad)
QinQ (IEEE802.1) tagging (also known as dot1q tunneling) is a technology that allows the nesting of an additional VLAN tag on a packet, in addition to an existing one. According to the standard, either VLAN tag is an 802.1Q header.
QinQ allows service providers to use a single VLAN to support customers who have multiple VLANs. The core service-provider network carries traffic with double-tagged, stacked VLAN (802.1Q-in-Q) headers of multiple customers while maintaining the VLAN and Layer 2 protocol configurations of each customer and without affecting the traffic of other customers.
Inventory and Information Model Objects (IMOs)
This section describes the following IMOs:
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Link Aggregation Group
The data link layer Link Aggregation Group object aggregates multiple Ethernet Interfaces, which it is bound to by its Containing Termination Points attribute. It is accessed primarily by the Virtual LAN Multiplexer bound by its Contained Connection Termination Points attribute. It is also accessed by the Common Components.
Table 4-1 Link Aggregation Group (ILinkAggregationGroup802dot3ad)
Group Number
Group identifier of the aggregated Ethernet interfaces
Any
Configuration
Bandwidth
Accumulated bandwidth of all aggregated Ethernet interfaces in Mb/s
Any
Configuration
Aggregation Protocol
Aggregation protocol (None, LACP, PAGP)
Any
Configuration
IANA Type
Internet Assigned Numbers Authority (IANA) type of the sublayer
N/A
N/A
Containing Termination Points
Underlying termination points (Ethernet Interface)
Any
N/A
Contained Connection Termination Points
Bound connection termination points
Any
N/A
Link Aggregation Group Port Entry
The Link Aggregation Group Port Entry object describes the Link Aggregation Control configuration parameters for each aggregation port of a Link Aggregation Group.
Ethernet Interface
The data link layer Ethernet Interface object is bound by its Containing Termination Points attribute to a physical layer interface (Ethernet Physical) object. It is accessed primarily by the Virtual LAN Multiplexer/Interface, Link Aggregation Group, Cisco Ethernet Channel or IP Interface bound by its Contained Connection Termination Points attribute. It is also accessed by the Bridging Entity.
Ethernet Physical
The physical layer Ethernet Physical object is bound by its Containing Termination Points attribute to a Port Connector object. It is accessed by the data link layer Ethernet Interface bound by its Contained Connection Termination Points attribute.
Table 4-4 Ethernet Physical (IPhysicalLayer)
All attributes are the same as those of Physical Layer (IPhysicalLayer).
Virtual LAN Interface
The data link layer Virtual LAN Interface object, which is used in a switched LAN environment, is bound by its Containing Termination Points attribute to an Ethernet Interface object. It is accessed primarily by the network layer object (such as IP Interface) bound by its Contained Connection Termination Points attribute. It is also accessed by the Bridging Entity.
Table 4-5 Virtual LAN Interface (IVlanInterface)
Mode
VLAN mode (Access, Trunk, 802.1Q Tunnel)
Any
Configuration
Native VLAN Identification
VLAN identifier, used for untagged received and transmitted frames
Any
Configuration
Virtual LAN Table
Array of VLAN Entries
Any
Configuration
IANA Type
Internet Assigned Numbers Authority (IANA) type of the sublayer
N/A
N/A
Containing Termination Points
Underlying termination points (connection or physical)
Any
N/A
Contained Connection Termination Points
Bound connection termination points
Any
N/A
Virtual LAN Entry
The Virtual LAN Entry object describes the association of a Virtual LAN Interface, which operates in Trunk mode, to one of the bridged Virtual LANs configured in the device.
Virtual LAN Multiplexer
The Virtual LAN Multiplexer object, used in a routed LAN environment, is bounded by its Containing Termination Points attribute to an Ethernet Interface object. It is accessed primarily by the data link layer Virtual LAN Encapsulations bound by its Contained Connection Termination Points attribute.
Table 4-7 Virtual LAN Multiplexer (IVlanEncapMux)
IANA Type
Internet Assigned Numbers Authority (IANA) type of the sublayer
N/A
N/A
Containing Termination Points
Underlying termination points (Ethernet Interface)
Any
N/A
Contained Connection Termination Points
Bound connection termination points (Virtual LAN Encapsulations)
Any
N/A
Virtual LAN Encapsulation
The data link layer Virtual LAN Encapsulation object, used in a routed LAN environment, is bound by its Containing Termination Points attribute to a Virtual LAN Multiplexer object. It is accessed primarily by the Network layer object (such as IP Interface) bound by its Contained Connection Termination Points attribute. It is also accessed by the Bridging Entity.
Data Link Aggregation Container
The Data Link Aggregation Container object aggregates or contains a single type of data link aggregation, such as Link Aggregation Group or Cisco Ethernet Channel.
Table 4-9 Data Link Aggregation Container (IDataLinkAggregationContainer)
Data Link Aggregations
Array of single-type data link aggregations (Link Aggregation Group, Cisco Ethernet Channel)
Any
Configuration
Type
Aggregation type (Null, Ethernet Link Aggregator)
Any
Configuration
Spanning Tree Protocol Service
The Spanning Tree Protocol Service object is used in a switched LAN environment. It describes the Spanning Tree Protocol service. It is accessed only by the Logical Root's Services List attribute.
Table 4-10 Spanning Tree Protocol Service (IStpService)
Protocol Type
Spanning Tree Protocol type (Unknown, STP, RSTP, PVSTP, MST)
Any
Configuration
Current and Bridge Maximum Age
The current used value, and the value that all bridges should use when this bridge is acting as the root, for the maximum age of learned Spanning Tree Protocol port information (in hundredths of seconds)
Any
Configuration
Current and Bridge Hello Time
The current used value, and the value that all bridges should use when this bridge is acting as the root, for hello time messages' keepalive interval of a Spanning Tree Protocol root (in hundredths of seconds)
Any
Configuration
Current and Bridge Forward Delay
The current used value, and the value that all bridges should use when this bridge is acting as the root, for port delay in each of the listening and learning states, preceding the forwarding one (in hundredths of seconds)
Any
Configuration
Instance Information Table
Any
Configuration
All additional attributes are the same as System Service (ISystemService)
Multiple Spanning Tree Protocol Service
The Multiple Spanning Tree Protocol Service object is used in a switched VLAN environment. It describes the Spanning Tree Protocol service. It is accessed only by the Logical Root's Services List attribute.
Table 4-11 Multiple Spanning Tree Protocol Service (IMstService)
Protocol Properties
Multiple Spanning Tree Protocol properties
Any
Configuration
All additional attributes are the same as Spanning Tree Protocol Service (IStpService).
Multiple Spanning Tree Protocol Properties
The Multiple Spanning Tree Protocol Properties object, used in a switched VLAN environment. It describes the Multiple Spanning Tree Protocol properties. It is accessed only by the Multiple Spanning Tree Protocol Service's Protocol Properties attribute.
Spanning Tree Protocol Instance Information
The following Rapid Spanning Tree Protocol Instance Information objects describe the instance information associated with and accessed by the Multiple Spanning Tree Protocol Service's Instance Information Table attribute.
Multiple Spanning Tree Protocol Instance Information
Table 4-14 Multiple Spanning Tree Protocol Instance Information (IMstInstanceInfo)
Instance Identification
Multiple Spanning Tree Protocol instance identifier
Any
Configuration
All additional attributes are the same as Spanning Tree Protocol Instance Information (IStpInstanceInfo)
Per-VLAN Spanning Tree Protocol Instance Information
Table 4-15 Per-VLAN Spanning Tree Protocol Instance Information (IPvstpInstanceInfo)
Protocol Type
Spanning tree protocol type (Unknown, STP, RSTP, PVSTP, MST)
Any
Configuration
Current and Bridge Maximum Age
The current used value, and the value that all bridges should use when this bridge is acting as the root, for the maximum age of learned Spanning Tree Protocol port information (in hundredths of seconds)
Any
Configuration
Current and Bridge Hello Time
The current used value, and the value that all bridges should use when this bridge is acting as the root, for hello time messages' keepalive interval of a Spanning Tree Protocol root (in hundredths of seconds)
Any
Configuration
Current and Bridge Forward Delay
The current used value, and the value that all bridges should use when this bridge is acting as the root, for port delay in each of the listening and learning states, preceding the forwarding one (in hundredths of seconds)
Any
Configuration
All additional attributes are the same as Spanning Tree Protocol Instance Information (IStpInstanceInfo)
Rapid Spanning Tree Protocol Instance Information
Table 4-16 Rapid Spanning Tree Protocol Instance Information (IRstpInstanceInfo)
Force Version
Force version (Unknown, STP, RSTP, PVSTP, MST)
Any
Configuration
All additional attributes are the same as Spanning Tree Protocol Instance Information (IStpInstanceInfo)
Spanning Tree Protocol Port Information
The following Spanning Tree Protocol Port Information objects describe the port information associated with and accessed by the Spanning Tree Protocol Instance Information's Port Information Table attribute.
Multiple Spanning Tree Protocol Port Information
Table 4-18 Multiple Spanning Tree Protocol Port Information (IMstPortInfo)
Hello Time
Hello time messages' keepalive interval of a Spanning Tree Protocol root (in hundredths of a second)
Any
Configuration
All additional attributes are the same as Spanning Tree Protocol Port Information (IStpPortInfo)
Vendor-Specific Inventory and IMOs
Vendor-specific IMOs are implemented only for specific vendor devices. The following section describes a vendor-specific object for this technology:
Cisco Ethernet Channel
The Cisco Ethernet Channel data link layer object aggregates multiple Ethernet Interfaces, to which it is bound by its Containing Termination Points attribute. It is accessed primarily by the Virtual LAN Multiplexer/Interface or IP Interface bound by its Contained Connection Termination Points attribute. It is also accessed by the Bridging Entity.
Table 4-19 Cisco Ethernet Channel (IEthernetChannel)
Group Number
Group identifier of the aggregated Ethernet interfaces
Any
Configuration
Bandwidth
Accumulated bandwidth of all aggregated Ethernet interfaces, in Mb/s
Any
Configuration
Aggregation Protocol
Aggregation protocol (Manual, LACP, PAGP)
Any
Configuration
IANA Type
Internet Assigned Numbers Authority (IANA) type of the sublayer
N/A
N/A
Containing Termination Points
Underlying termination points (Ethernet Interface)
Any
N/A
Contained Connection Termination Points
Bound connection termination points
Any
N/A
Network Topology
Cisco ANA conducts discovery of Ethernet data link layer topology by searching for the local MAC address in any remote side's bridge or in ARP tables related to the same type of the local Ethernet port. The basic assumption, which is not always valid, is that every Ethernet port has a unique MAC address. This topology is also applied to the underlying physical links.
Further verification is done by matching the traffic signature of these ports using Cisco's confidential scheme, which requires a substantial amount of traffic to function correctly.
There is no topology based specifically on STP or QinQ technology in Cisco ANA. QinQ topology discovery can also complicate Ethernet discovery of links between LAN switches via CDP. Many service providers configure customer access to VLAN ports using L2PT in order to avoid the need to process layer 2 protocols like CDP. If these ports are also configured for QinQ, discovery may create links between ports which are not directly connected, because the CDP information is tunneled and does not reflect the actual physical links. Users can overcome this problem by configuring static links on these ports. The static links will override the incorrect dynamically-discovered links.
Service Alarms
The following alarms are supported for this technology:
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Note that these alarms, apart from Cloud Problem, are related to the underlying physical interface (see Common Components).
Cisco ANA does not generate service alarms specific to QinQ technology. However, correlation takes this technology into account when performing flow analysis.
For detailed information about alarms and correlation, see the Cisco Active Network Abstraction 3.6.6 User Guide.