Carrier Ethernet Services

Transcription

1 CHAPTER 6 The following topics describe how you can use Cisco ANA to monitor Carrier Ethernet services. Supported Carrier Ethernet Technologies, page 6-1 VLANs, page 6-2 STP, page 6-5 Cisco REP, page 6-6 VLAN Trunk Protocol, page 6-10 EFPs, page 6-10 Cisco ME 3400 UNI-ENI VLANs, page 6-11 EoMPLS, page 6-12 VPLS and H-VPLS, page 6-13 LLDP, page 6-15 Supported Carrier Ethernet Technologies Cisco ANA provides modeling and support for the following Carrier Ethernet protocols, technologies, and services: Virtual LANs (VLANs) Spanning Tree Protocol (STP) Resilient Ethernet Protocol (REP) VLAN Trunk Protocol (VTP) VLAN topology overlays and logical domains Cisco Discovery Protocol (CDP) Link Layer Discovery Protocol (LLDP) User Network Interface (UNI) and Enhanced Network Interface (ENI) ports Virtual Private LAN Service (VPLS) Virtual Switch Instances (VSIs) H-VPLS Q-in-Q 6-1

2 VLANs Chapter 6 Ethernet over MPLS (EoMPLS) This section provides an overview to Carrier Ethernet technologies supported in Cisco ANA. VLANs Cisco ANA provides VLAN modeling and display of underlying Layer 2 interfaces, that is, the switchport in access, trunk, and dot1q tunnel modes, and VLANs with their MAC address forwarding tables. In addition, Cisco ANA provides support for the following: Layer 3 VLAN interface with multiple VLAN tags, also known as flexible Q-in-Q or stacked VLANs. Layer 3 VLAN interface modeling includes support for basic dot1q interfaces, Q-in-Q interfaces with one tag, double tags, a range of tags, any tag, or a combination of tags as supported by Cisco IOS and Cisco IOS-XR Software. Layer 2 VLAN interfaces, also known as service instances in the Cisco 7600 Series router, including support for complex match criteria and rewrite information MUX-UNI Support on LAN Cards is a Cisco 7600 Series feature that provides the ability to partition a physical port on an attachment VLAN to provide multiple Layer 2 and Layer 3 services over a single UNI. The 7600-MUX-UNI is the configuration of Layer 3 subinterfaces on top of standard Layer 2 switchport on LAN cards. The Layer 3 subinterfaces that are supported in the LAN cards include a VLAN interface with one tag. Cisco ANA models VLAN interfaces in the Cisco ANA NetworkVision inventory window physical and logical inventory trees. Associations between an interface and a VLAN (including bridge and bridge domain), pseudowire, IP interface, or a local connection are also supported. VLAN-to-interface associations are shown in the following ways: Layer 2 VLAN interfaces (Ethernet flow points) are shown in the interface table of the bridge, or as the underlying termination point of a pseudowire. Layer 3 VLAN interfaces are shown in the interface table under the Routing Entities, VRF or LSE Logical Inventory items. In addition, VLAN interfaces are shown as underlying termination points of a pseudowire. VLAN Mapping Cisco ANA supports VLAN mapping on the Cisco 3400 Series Ethernet Access Switches and Cisco 3750 Metro Series Switches. VLAN mapping, or VLAN ID translation, is a feature configured on the Cisco 3400E and Cisco 3750 enhanced services (ES) ports connected to the SP network to map the customer VLANs to SP VLANs. VLAN mapping acts as a filter on the ES ports without affecting the internal operation of the switch or the customer VLANs. A switch might also have a number of reserved VLANs or have a limited VLAN range. When customers want to use a VLAN number in the reserved range, you can use VLAN mapping to overlap customer VLANs (C-VLANs) by encapsulating the customer traffic in IEEE 802.1Q tunnels. With VLAN mapping, the customer VLAN ID in the IEEE 802.1Q tag, or the inner and outer tag in an IEEE 802.1Q tunneled frame, are mapped (or translated) just before a packet is transmitted and just after a packet is received. The SP VLANs (S-VLANs) are not seen by the switch, so all configuration and statistics are done with the C-VLANs. The switch supports three types of VLAN mapping: One-to-one mapping that maps the C-VLAN ID in the IEEE 802.1Q tag to the S-VLAN ID. 6-2

3 Chapter 6 VLANs Two-to-one mapping that maps IEEE 802.1Q tunneling traffic with the outer and inner VLAN IDs to the S-VLAN ID. Two-to-two mapping that maps IEEE 802.1Q tunneling traffic with the outer and inner VLAN IDs to the SP outer and inner VLAN IDs. The customer IEEE 802.1Q VLAN IDs are used to switch the packet inside the switch. The S-VLAN IDs are sent or received on the ES ports. Mapping Customer VLANs to Service Provider VLANs Figure 6-1 shows a topology where a customer uses the same VLANs in multiple sites at different sides of an SP network. The C-VLAN IDs are mapped to S-VLAN IDs for packet travel across the SP backbone. The C-VLAN IDs are retrieved at the other side of the SP backbone for use at the other customer site. Figure 6-1 VLAN Mapping Example Host Customer A VLANs 1-5 Customer switches Customer A VLANs 1-5 Service provider Catalyst 3750 Catalyst 3750 Metro switch A Metro switch B Access, ISL, or 802.1Q trunk Catalyst 6500 Customer switch Access, ISL, or 802.1Q trunk Customer A VLANs 1-5 Host VLAN mapping at enhanced services ports The Cisco ME3400E supports the following VLAN mapping types on UNI trunk ports: One-to-one VLAN mapping occurs at the ingress and egress of the port and maps the customer C-VLAN ID in the 802.1Q tag to the S-VLAN ID. QinQ maps the specified C-VLANs entering the UNI to the specified S-VLAN ID. The S-VLAN is added to the incoming unmodified C-VLAN. Traditional 802.1Q tunneling (QinQ) performs all-to-one bundling of C-VLAN IDs to a single S-VLAN ID for the port. The S-VLAN is added to the incoming unmodified C-VLAN. The UNI can be configured as an 802.1Q tunnel port for traditional QinQ, or as selective QinQ on trunk ports. Mapping takes place at ingress and egress of the port. All packets on the port are bundled into the specified S-VLAN. 6-3

4 VLANs Chapter 6 VLAN Mapping IMOs Table 6-1 shows the Cisco ANA IMO attributes that handle the VLAN mapping. Table 6-1 VLAN Mapping IMOs IMO Attribute Name Description IVlanInterface VlanMappings An array of all VLAN Mappings (IVlanMapping) defined for this VLAN interface (IVlanInterface). IVlanMapping Direction Indicates whether the VLAN mapping is egress or ingress. VLANRewriteDefinition The rewrite actions, such as push tag and pop tag, performed on the frames that fit the match criteria. VLANMatchCriteria Defines the criteria that identify the frames that will undergo this VLAN mapping. Drop Defines whether or not the frame should be dropped, instead of rewritten. In Cisco ANA NetworkVision, the VLAN mappings appear in the VLAN Mappings tab in the device Ethernet port, as shown in Figure 6-2. Table properties include: Direction VLAN Inner VLAN Translated VLAN Translated Inner VLAN Action 6-4

5 Chapter 6 STP Figure 6-2 VLAN Mapping Table VLAN Mappings table STP Spanning Tree Protocol (STP) is a link management protocol that provides path redundancy while preventing undesirable loops in the network. For an Ethernet network to function properly, only one active path can exist between two stations. Multiple active paths between stations cause loops in the network. If a loop exists in the network topology, the potential exists for message duplication. When loops occur, some switches see stations appear on both sides of the switch. This condition confuses the forwarding algorithm and allows duplicate frames to be forwarded. To provide path redundancy, STP defines a tree that spans all switches in an extended network. STP forces certain redundant data paths into a standby (blocked) state. If one network segment in the STP becomes unreachable, or if STP costs change, the spanning-tree algorithm reconfigures the spanning-tree topology and reestablishes the link by activating the standby path. Cisco ANA supports the following STP versions: Rapid Spanning Tree Protocol (RSTP) Per-VLAN Spanning Tree (PVST and PVST+) Multiple Spanning Tree Protocol (MSTP) Rapid Per-VLAN Spanning Tree (R-PVST) Cisco ANA supports the following PVST and PVST+ enhancements: PortFast Guard Enables immediate edge port transition into the forwarding or blocking state without calculations. UplinkFast Enables access switches to maintain backup paths to the root. BackboneFast Enables immediate expiration of the Max Age timer on an indirect link failure. 6-5

6 Cisco REP Chapter 6 Cisco ANA supports the following PVST and PVST+ protection mechanisms: BPDU Guard Helps keep an active topology predictable. Devices behind the ports that have PortFast Guard enabled cannot influence the STP topology. When bridge protocol data units (BPDUs) arrive, the BPDU guard disables the port that has PortFast Guard configured. Generally, in PVST, every port configured as PortFast is also configured as BPDU Guard. BPDU Filter Prevents the transmission of BPDUs on PortFast-enabled ports that are connected to an end system. When you enable PortFast on the switch, Spanning Tree places ports in the forwarding state immediately, instead of going through the listening, learning, and forwarding states. Generally, in PVST, every port configured as PortFast is also configured as a BPDU Filter. Root Guard Prevents a port from becoming the root. Loop Guard Prevents a blocked port from moving to listening after the maximum age timer expires. Cisco REP Cisco Resilient Ethernet Protocol (REP) is implemented on Cisco Carrier Ethernet switches and intelligent service edge routers to provide fast network and application convergence. Cisco REP is a segment protocol that integrates into existing Carrier Ethernet networks. REP interoperates with STP, but allows network architects to limit the scope of STP domains. Cisco REP is a distributed and secure protocol that does not rely on a master node to control the ring status. Failures are detected locally either through loss of signal (LOS) or loss of neighbor adjacency. Any REP port can initiate a switchover as long as it has acquired the secure key to unblock the alternate port. By default, REP elects an alternate port unless the administrator defines a preferred port. For bandwidth usage and traffic engineering, REP supports load balancing per group of VLANs. Cisco REP Topologies Cisco REP is a segment protocol; an REP segment is a chain of ports connected to each other and configured with the same segment ID. Each end of a segment terminates on an CE switch or edge router. The port where the segment terminates is called the edge port, as shown in Figure 6-3. Figure 6-3 Cisco REP Topology Edge Switch Edge Port Edge Port Segment

7 Chapter 6 Cisco REP Cisco REP Operation In Cisco REP, at least one port is always blocked in any given segment. The blocked port, also known as the alternate port, helps to ensure that the traffic within the segment is loop-free by requiring traffic flow to exit only one of the edge ports, and not both. When a segment failure occurs, REP opens the alternate port so traffic can reach the segment edge (Figure 6-4). Figure 6-4 Cisco REP Topology REP Segment Edge Port Alternate Port Edge Port Blocked REP Segment Edge Port Forward Edge Port Failed Cisco REP Fault Detection REP relies primarily on LOS to detect a link failure, and can always learn the location of the failure within the ring. When a failure occurs, the failed ports immediately send link failure notifications to all REP peers. The failure notification: Instructs the alternate port to immediately unblock because the segment is broken. Flushes MAC entries on all REP ports within the segment. A REP node maintains neighbor adjacencies and continuously exchanges hello packets with its neighbors. In scenarios where LOS is not detected, the loss of a REP adjacency also triggers a switchover. Neighbor adjacency awareness is unique to REP and has advantages over alternate polling mechanisms that require centralized management from a master node. To ensure reliable and fast notification, REP propagates the notifications using the following two methods: Fast notification Uses a Cisco multicast address. The notification is forwarded in hardware so that each node in the segment is notified immediately without software involvement from any node. Reliable notification Is distributed through the REP Adjacency Protocol; the notification is retransmitted if lost. The protocol uses sequence numbering and relies on packet acknowledgment. 6-7

8 Cisco REP Chapter 6 Table 6-2 REP IMO Attributes IMO Attribute Description IREPService version The version of REP being used. administrativevlan The administrative VLAN used by REP to transmit its hardware flooding layer messages, notificationenabled Specifies whether the system will generate REP notifications. segmentstable The segments defined on the device. IREPSegmentInfo segmentid The segment ID. segmentcomplete Indicates whether the segment is complete, that is, no segment port is in failed state. portstable The device ports that are part of this segment. IREPPortInfo portname The interface name. portoid Port object ID. segmentid The segment that the interface is part of. porttype Port type: Primary, Secondary, Intermediate. portrole Indicates the REP port role or state depending on its link status and whether it is forwarding or blocking traffic: Failed, Alternate, Open. operportstatus Indicates the current operational link state of the REP port: None, Init Down, No Neighbor, One Way, Two Way, Flapping, Wait, or Unknown. blockedvlans The list of VLANs configured to be blocked at the alternate port. This value is only effective on the alternate port. preempttimer Specifies the time interval that REP waits before triggering preemption after the segment is complete: 0 to 300 or Disabled. Disabled indicates that no time delay is configured and the preemption will occur manually. This value is only effective on the device acting as the REP primary edge. lslageouttimer The Link Status Layer age-out timer. This is the time, in milliseconds, that the REP interface remains up without receiving a hello from a neighbor. remotedevicename The name of the neighbor device that this port is connected to on this segment (may be null). remotedevicemac The MAC address of the neighbor bridge that the port is connected to on this segment (can be null). remoteportname The name of the neighbor port on the neighbor bridge that this port is connected to on this segment (can be null). 6-8

9 Chapter 6 Cisco REP In Cisco ANA NetworkVision, the Cisco REP information is displayed under the Resilient Ethernet Protocol logical inventory item. Figure 6-5 shows the REP segments. Figure 6-5 REP Segments Table Figure 6-6 shows the ports contained in an REP segment. Figure 6-6 REP Segments Ports 6-9

10 VLAN Trunk Protocol Chapter 6 VLAN Trunk Protocol VTP is a Cisco-proprietary, Layer 2 multicast messaging protocol that manages the addition, deletion, and renaming of VLANs on a switched network-wide basis. (VTP is a available on most of the Cisco Catalyst Series products.) When you configure a new VLAN on one VTP server, the VLAN is distributed through all switches in the domain. This reduces the need to configure the same VLAN everywhere. VTP reduces manual configuration steps, minimizes configuration mismatches, and makes VLAN additions, deletions, and renaming more secure. A VTP domain (also called a VLAN management domain) is made up of one or more interconnected switches that share the same VTP domain name. A switch can be in only one VTP domain and in one of the following VTP modes: Server In VTP server mode, you can create, modify, and delete VLANs and specify other configuration parameters, such as VTP version and VTP pruning, for the entire VTP domain. VTP servers advertise their VLAN configuration to other switches in the same VTP domain and synchronize their VLAN configuration with other switches based on advertisements received over trunk links. VTP server is the default mode. Client VTP clients behave the same way as VTP servers, but you cannot create, change, or delete VLANs on a VTP client. Transparent VTP transparent switches do not participate in VTP. The switch does not advertise its VLAN configuration and does not synchronize its VLAN configuration based on received advertisements. However, switches in transparent mode do forward VTP advertisements that they receive out their trunk ports in VTP Version 2. Switches in VTP transparent mode can create and modify VLANs, but the changes affect only the individual switch. Off The same behavior as VTP transparent mode with the exception that VTP advertisements are not forwarded. EFPs An Ethernet Flow Point (EFP) is a forwarding decision point in the PE router, which gives network designers flexibility to make many Layer 2 flow decisions within the interface itself. Many EFPs can be configured on a single physical port. (The number varies from one device to another.) EFPs are the logical demarcation points of an Ethernet virtual connection (EVC) on an interface. An EVC that uses two or more UNIs requires an EFP on the associated ingress and egress interfaces of every device that the EVC passes through. EFPs can be configured on any Layer 2 traffic port; however, they are usually configured on UNI ports. The following parameters can be configured on the EFP: Match criteria Defines the matching rules of the frames that should enter the EFP. The matching rules can be for: Frames of a specific VLAN, a VLAN range, or a list of VLANs ( or 100,103,110). Frames with no tags (untagged). Frames with the same double-tags (VLAN tags) as specified. Frames with same Class of Service (CoS). A frame passes each configured match criterion until the correct matching point is found. If a frame does not fit any of the matching criteria, it is dropped. Default criteria can be configured to avoid dropping frames. 6-10

11 Chapter 6 Cisco ME 3400 UNI-ENI VLANs Rewrite commands In each EFP, VLAN tag management can be specified with the following actions: Pop 1) pops out a tag; 2) pops out two tags. Push 1) pushes in a tag; 2) pushes in two tags. Translate 1 to 1) changes a tag value; 1 to 2) pops one tag and pushes two tags; 2 to 1) pops two tags and pushes one tag; 2 to 2) changes the value for two tags. Forwarding commands Each EFP specifies the forwarding command for the frames that enter it. Only one forwarding command can be configured per EFP. The forwarding options are: Layer 2 Point-to-Point Forwards to a pseudowire tunnel. Multipoint Bridging Forwards to a bridge domain entity. Local Switching Switches between two different interfaces. Feature commands Change QoS parameters and update the ACL In addition, the direction of the configuration can be indicated. The symmetric option indicates whether or not this configuration is the same for the both ingress and egress traffic. EFPs are implemented as service instances for Cisco 7600 Series Routers, or as subinterfaces for the Cisco ASR 9000 Aggregation Services Routers. These two implementations function identically. Cisco ANA displays EFP information on the port physical inventory, and on the VLAN bridge and link aggregation group logical inventories. Cisco ME 3400 UNI-ENI VLANs Cisco ME 3400 Series Ethernet Access Switches allow the following port types to be provisioned: User network interface (UNI) The demarcation point between the service provider and the customer network. UNIs connect to hosts, such as IP phones and other devices. By default, a UNI port is in disabled admin state; it blocks any Layer 2 control protocol such as CDP and STP. Enhanced network interface (ENI) Provides the same functionality as the UNI port. However, ENIs can be configured to pass Layer 2 control protocols, including: CDP LLDP STP EtherChannel Link Aggregation Control Protocol Port Aggregation Protocol Network-to-network interface (NNI) The demarcation point between service provider networks. NNI ports are used to connect to other Ethernet switches or routers and are in the enabled admin state by default. NNI ports do not have any filtering restrictions. Each port type has specific default characteristics that determine its functionality. For example,10/100m ports are generally configured as UNIs with two SFPs configured as NNIs (Cisco ME TS). Each port can be configured as another type and subsequently, the port inherits the default behavior of the additional type. The Cisco ME 3400 Series switches allow the provisioning of UNI-ENI VLANs. UNI-ENI VLANs are associated to a UNI-ENI port connected to CE devices on the customer network and used to isolate traffic arriving at the VLAN from different customers. UNI-ENI VLANs can have two states: isolated and 6-11

12 EoMPLS Chapter 6 community. In the default isolated state, the VLAN does not forward traffic between any UNI-ENI ports. Traffic can pass between NNIs and between NNI and UNI-ENI ports. In community state, the VLAN passes traffic between UNI-ENI ports without any restrictions. In Cisco ANA NetworkVision, UNI-ENI VLANs are identified in the VLAN Type property under the Bridges logical inventory. Port types are displayed under the physical inventory port properties. EoMPLS Cisco ANA provides discovery, inventory, and impact analysis for pseudowires by associating customer and service provider VLANs to the pseudowires that carry them. Cisco ANA discovers VLANs carried by pseudowires in the following two configurations: VLAN Mode An MPLS pseudowire connects two VLAN networks that are in different locations. This pseudowire is configured as a point-to-point VC between two PE routers at each end of the MPLS backbone. Only the two PE routers at the ingress and egress points of the MPLS backbone know about the VCs dedicated to transporting Layer 2 VLAN traffic. No other routers have table entries for those VCs. A logical cross-connect joins the VLAN to the VC or pseudowire. Port Mode Ethernet frames coming into an interface can be packed into an MPLS packet and transported over the MPLS backbone to an egress interface. The entire Ethernet frame without the preamble or frame check sequence is transported as a single packet. A port is mapped to an MPLS pseudowire through the xconnect command in interface configuration mode. The xconnect CLI command includes the destination address of the peer PE and the VC ID. The syntax of the xconnect command is the same as for all other transport types. Each interface is associated with one unique pseudowire VC label. Figure 6-7 shows the basic components of an Ethernet over MPLS (EoMPLS) configuration. Figure 6-7 EoMPLS Configuration Ethernet Attachment Circuit VLAN Ethernet Emulated Ethernet Sevice Pseudowire Emulated Virtual Circuit Ethernet Attachment Circuit VLAN Ethernet Site 1A Site 2A CE 1A CE 2A VLAN Ethernet (port mode) PE1 Pseudowire MPLS Core Pseudowire PE2 VLAN Ethernet (port mode) CE 1B CE 2A Site 1B Site 2B CE 2B For EoMPLS implementations, Cisco ANA: Discovers VLAN to pseudowire cross-connects (xconnect in Cisco IOS CLI) within PE network elements. Discovers of Ethernet port-to-pseudowire cross-connects within PE network elements. 6-12

13 Chapter 6 VPLS and H-VPLS Discovers the CE-VLAN IDs presented at the UNI and mapped to the pseudowire carrying service frames across the metro Ethernet network (MEN). Discovers ports presented at the UNI and to the pseudowire that carries service frames across the MEN. VLAN IDs are sometimes specified as CE-VLAN ID service attribute for this UNI. Associates an Ethernet virtual connection (EVC) and EVC service (EVCS) attributes with the pseudowire carrying CE-VLANs. Identifies impacted CE-VLANs and CE-VLAN sites from alarms on pseudowires carrying the CE-VLANs and adds the information to alarm tickets and service topology views. VPLS and H-VPLS VPLS offers multipoint Ethernet LAN services over MPLS networks. A VPLS offers the same connectivity as an NE attached to an Ethernet switch. The VPLS architecture that links VSIs using MPLS pseudowires forms an emulated Ethernet switch. Figure 6-8 shows a basic VPLS configuration. Figure 6-8 VPLS Configuration N-PE N-PE Tunnel LSP CE CE PW PW PW CE CE CE Red VSI Blue VSI Green VSI CE Red VSI Blue VSI Green VSI CE CE Legend CE Customer Edge Device N-PE Network Facing Provider Edge VSI Virtual Switch Instance PW Pseudowire Tunnel LSP Tunnel Label Switch Path that provides PW transport Blue VSI Red VSI VPLS offers two types of service: Transparent LAN Service (TLS) Ethernet Virtual Connection Service (EVCS) 6-13

14 VPLS and H-VPLS Chapter 6 TLS is used for bridging protocol transparency; for example, bridge protocol data units (BPDUs) and VLAN values. Bridges see this service as an Ethernet segment. EVCS is used when routers need to reach multiple intranet and extranet locations from a single physical port. Routers see subinterfaces through which they access other routers. TLS and EVCS services differ in how they learn MAC addresses and process BPDUs. TLS performs unqualified learning. All customer VLANs of a Layer 2 VPN are treated as if they were in the same broadcast domain. In EVCS, the outer VLAN tag on the Ethernet packet differentiates one customer VLAN instance from another. Each VLAN has its own MAC address space, which allows qualified learning. In qualified learning, MAC addresses of different VLANs might overlap with one another, and each VLAN has a separate Layer 2 forwarding table. VPLS requires that the edge NE be MPLS-capable and participate in routing protocols and the LDP. Hierarchical VPLS (H-VPLS) partitions the network into several edge domains that are interconnected using an MPLS core. The edge NEs only learn of their local N-PE network elements and therefore do not need large routing table support. The edge domain can also be built using Ethernet switches and techniques such as Q-in-Q. Figure 6-9 shows an H-VPLS configuration example. Figure 6-9 H-VPLS Configuration U-PE PE-CLE N-PE N-PE MTU-s GE PE-POP PE-POP GE PE-rs PE-rs PW U-PE PE-CLE MTU-s Ethernet Edge Point-to-point MPLS Core Ethernet Edge GE Ring For VPLS and H-VPLS implementations, Cisco ANA: Discovers virtual forwarding instance (VFI) configurations and the pseudowire configurations associated with that VFI. For NEs that support VPLS, discovers the following VPLS attachment circuit type connections: Access Sends and accepts untagged Ethernet packets only. Tagged Ethernet VLAN packets are dropped. Trunk Sends and receives tagged Ethernet VLAN packets and native VLAN packets. For NEs that support H-VPLS: Discovers the Q-in-Q attachment circuit connection to VPLS. Discovers the connection of an MPLS pseudowire attachment circuit to VPLS. Discovers pseudowire attachment circuits configured under VFIs. 6-14

15 Chapter 6 LLDP LLDP Link Layer Discovery Protocol (LLDP) operates on the data link layer. It stores and maintains the local device information, including a list of devices directly connected to the device. LLDP enables network administrators to manage networks through network management systems (NMSs). LLDP encapsulates device information in LLDP data units (LLDPDUs), which are formatted in type, length, and value (TLV) triplets. Devices that are directly connected exchange LLDPDUs. Each device stores the received LLDPDU information in standard MIBs. Cisco ANA collects and displays LLDP information in two places: Logical inventory In the Cisco ANA NetworkVision logical inventory, the LLDP item displays the general LLDP definitions, such as advertisement interval, hold time, and re-initialization delay). It also lists all the device neighbors, as learned from LLDPDU exchanges. Layer 2 ports Each Layer 2 port in the physical inventory displays its relevant LLDP Tx and Rx parameters. 6-15

16 LLDP Chapter