Table Of Contents
Internet Protocol "IP"
Technology Description
IP
ARP
HSRP
GRE
Inventory and Information Model Objects (IMOs)
IP Interface
IP Multiplexer Entry
IP Interface Address
IP Subnetwork
Routing Entity
Equivalent Routing Entry
Routing Entry
ARP Entity
ARP Entry
IP Address Pool
IP Range Based Address Pool Entry
IP Subnet Based Address Pool Entry
Hot Standby Router Protocol (HSRP) Group Entry
Generic Routing Encapsulation (GRE) Tunnel Interface
Network Topology
Service Alarms
Internet Protocol "IP"
This chapter describes the level of support that Cisco ANA provides for IP, as follows:
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Technology Description
•
Inventory and Information Model Objects (IMOs)
•
Network Topology
•
Service Alarms
Technology Description
IP
The Internet Protocol (IP) is a network layer (Layer 3) protocol that contains addressing information and some control information that enables packets to be routed. IP is documented in RFC 791 and is the primary network layer protocol in the Internet protocol suite. Along with the Transmission Control Protocol (TCP), IP represents the heart of the Internet protocols. IP has two primary responsibilities: providing connectionless, best-effort delivery of datagrams through an inter-network; and providing fragmentation and reassembly of data-grams to support data links with different Maximum Transmission Unit (MTU) sizes.
ARP
Address Resolution Protocol (ARP) is a protocol for mapping an Internet Protocol address (IP address) to a physical machine address, known as a Media Access Control or MAC address that is recognized in the local network. For example, in IP Version 4, the most common level of IP in use today, an address is 32 bits long. In an Ethernet local area network, however, addresses for attached devices are 48 bits long. A table, usually called the ARP cache, is used to maintain a correlation between each MAC address and its corresponding IP address. ARP provides the protocol rules for making this correlation and providing address conversion in both directions.
HSRP
Hot Standby Router Protocol (HSRP) is a routing protocol that provides automatic router backup by allowing host computers on the Internet to use multiple routers that act as a single virtual router, maintaining connectivity even if the first hop router fails, because other routers are on hot standby and ready to go. The protocol is fully compatible with Novell's Internetwork Packet Exchange (IPX), AppleTalk, and Banyan VINES, and (in some configurations) with Xerox Network Systems (XNS) and DECnet.
Developed by Cisco and specified in RFC 2281, HSRP ensures that only a single router (called the active router) is forwarding packets on behalf of the virtual router at any given time. A standby router is chosen to be ready to become the active router, in the event that the current active router fails. HSRP defines a mechanism used to determine active and standby routers by referring to their IP addresses. Once these are determined, the failure of an active router will not cause any significant interruption of connectivity.
On any given LAN, there may be multiple, possibly overlapping, hot standby groups, each with a single Media Access Control (MAC) address and IP address; the IP address should belong to the primary subnet, but must be different from any actual or virtual addresses allocated to any routers or hosts on the network.
GRE
Generic Routing Encapsulation (GRE) is a tunneling protocol, originated by Cisco Systems and standardized in RFC 2784. It was designed to encapsulate a wide variety of network layer packets inside IP tunneling packets. The original packet is the payload for the final packet. The protocol is used on the Internet to secure virtual private networks.
Inventory and Information Model Objects (IMOs)
This section includes the following tables:
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IP Interface (IIPInterface)
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IP Multiplexer Entry (IIPMuxEntry)
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IP Interface Address (IIPInterfaceAddress)
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IP Subnetwork (IPSubnet)
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Routing Entity (IRoutingEntity)
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Equivalent Routing Entry (IRoutingEntries)
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Routing Entry (IRoutingEntry)
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ARP Entity (IARPEntity)
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ARP Entry (IARPEntry)
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IP Address Pool (IIPPool)
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IP Range Based Address Pool Entry (IIPRangeBasedIPPoolEntry)
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IP Subnet Based Address Pool Entry (IIPSubnetBasedIPPoolEntry)
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Hot Standby Router Protocol (HSRP) Group Entry (IHSRPGroupEntry)
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Generic Routing Encapsulation (GRE) Tunnel Interface (ITunnelGRE)
IP Interface
The following network layer IP Interface object, which represents the IP level functionality of an interface configuration in a network element, is primarily bound by its Containing Termination Points attribute to a Data Link Layer Interface object, and is primarily accessed by a Routing Entity.
Table 2-1 IP Interface (IIPInterface)
Attribute Name
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Attribute Description
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IP Address
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Primary IP address
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Subnetwork Mask
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Primary IP subnetwork mask
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IP Interface Addresses
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Array of all IP Interface Addresses
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Interface Name
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Interface name
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Interface Description
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Interface description
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IP Interface State
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IP interface state (Unknown, Up, Down)
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OSPF Interface Cost
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2x10^9/<interface speed in BPS>
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MTU
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Maximum transmit units
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Lookup Method
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Lookup method (Route Table First, Host Table First)
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Address Resolution Type
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Address resolution type/s
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ARP Timeout
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ARP table entry aging timeout
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Secured ARP
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Secured ARP settings (Enable, Disable)
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ICMP Mask Reply
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Control message mask reply
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IGMP Proxy
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Group management proxy
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HSRP Groups
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Arrays of Hot Standby Router Protocol (HSRP) Group Entry (valid only for Cisco routers that implement HSRP)
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IP Multiplexing Table
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Array of IP Multiplexing Entries
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IANA Type
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IANA type of the sub/layer
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Containing Termination Points
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Underlying termination points (connection or physical)
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Contained Connection Termination Points
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Bound Connection Termination Points
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IP Multiplexer Entry
The following IP Multiplexer Entry object, of the IP Multiplexing Table of an IP Interface object, is used when an IP Interface is bound to multiple Virtual Connection based Data Link layer interfaces such as ATM Interface and Frame Relay Interface in order to map a Destination IP Subnet with a specific Virtual Connection.
Table 2-2 IP Multiplexer Entry (IIPMuxEntry)
Attribute Name
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Attribute Description
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Termination Point
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Virtual data link layer encapsulation
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Destination IP Subnet
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Destination IP subnet
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IP Interface Address
The following IP Interface Address object describes one of possible multiple IP Addresses along with their Subnetwork Masks assigned to an IP Interface, using an IP Subnetwork object, and whether it is the Primary or a Secondary one.
Table 2-3 IP Interface Address (IIPInterfaceAddress)
Attribute Name
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Attribute Description
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Type
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IP address type (Primary, Secondary)
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IP Subnet
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IP subnetwork
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IP Subnetwork
The following IP Subnetwork type (not an IMO object) describes an IP Subnetwork Address (with the host part being zeroed) or alternatively a Host IP Address along with the IP Subnetwork Mask.
Table 2-4 IP Subnetwork (IPSubnet)
Attribute Name
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Attribute Description
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IP Address
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IP address
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Subnetwork Mask
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IP subnetwork mask
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Routing Entity
The following Routing Entity object describes the routing and address resolution protocols independent forwarding component of an IP router, which is bound by its Logical Sons attribute to all Network layer IP Interface objects, which IP Packets are being routed between, by this Routing Entity.
Equivalent Routing Entry
The following Equivalent Routing Entry and Routing Entry objects describe a routing table's entries, each as an array of routing entries sharing a single IP Subnetwork destination. Based on their protocol type some of the device's routing table's entries, which are not relevant to the IMO model, may not be presented in this table structure.
Table 2-6 Equivalent Routing Entry (IRoutingEntries)
Attribute Name
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Attribute Description
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Routing Entries
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Array of Routing Entries (sharing a single destination)
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Routing Entry
Table 2-7 Routing Entry (IRoutingEntry)
Attribute Name
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Attribute Description
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Destination IP Subnet
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Final destination IP subnet
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Next Hop IP Address
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Next hop IP address
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Type
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Route entry type (Null, Other, Invalid, Direct, Indirect, Static)
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Routing Protocol Type
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Routing protocol type (Null, Other, "Local, Network Managed, ICMP, EGP, GGP, Hello, RIP, IS-IS, ES-IS, Cisco IGRP, BBN SPF IGP, OSPF, BGP, EIGRP)
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Outgoing Interface Name
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Outgoing IP interface name
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ARP Entity
The following ARP Entity object describes a routing domain wide Internet Protocol (IP) address to Media Access Control (MAC) Address Resolution Protocol Entity.
Table 2-8 ARP Entity (IARPEntity)
Attribute Name
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Attribute Description
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ARP Table
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Array of ARP Entries
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ARP Entry
The following ARP Entry object describes a routing domain wide Internet Protocol (IP) address to Media Access Control (MAC) Address Resolution Protocol Table's Entry.
Table 2-9 ARP Entry (IARPEntry)
Attribute Name
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Attribute Description
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IP Address
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Internet Protocol (IP) address
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MAC Address
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Media Access Control (MAC) address
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Port
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Data link layer (MAC) interface
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Entry Type
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ARP entry type (Null, Other, Invalid, Dynamic, Static)
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IP Address Pool
The following IP Address Pool with its IP Range Based Address Pool Entry and IP Subnet Based Address Pool Entry objects describe an IP Address Pool of a Gateway/Router device for distribution to local and remote parties by protocols such as DHCP and IPCP.
IP Range Based Address Pool Entry
Table 2-11 IP Range Based Address Pool Entry (IIPRangeBasedIPPoolEntry)
Attribute Name
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Attribute Description
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Start IP Address
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Start IP address of the IP address pool
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End IP Address
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End IP address of the IP address pool
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Unused Addresses
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Unused addresses count
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Used Addresses
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Used addresses count
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Reserved Addresses
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Reserved addresses count
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IP Subnet Based Address Pool Entry
Table 2-12 IP Subnet Based Address Pool Entry (IIPSubnetBasedIPPoolEntry)
Attribute Name
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Attribute Description
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IP Subnet
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IP Subnetwork of the IP address pool
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Unused Addresses
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Unused addresses count
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Used Addresses
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Used addresses count
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Reserved Addresses
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Reserved addresses count
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Hot Standby Router Protocol (HSRP) Group Entry
The following Cisco Specific Hot Standby Router Protocol (HSRP) Group Entry object, describes both the configuration and the outcome information of running this protocol within a group (two) of routers, connected to the same segment of Ethernet networks for providing backup to a router in the event of failure, by presenting an appearance of a single virtual router with a single set of IP and MAC addresses on that Local Area Network (LAN).
Table 2-13 Hot Standby Router Protocol (HSRP) Group Entry (IHSRPGroupEntry)
Attribute Name
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Attribute Description
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Group Number
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Group number
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Port Description
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Port description
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Priority
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Priority from 0 (Lowest) to 255 (Highest) used for active router selection
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Coupled Router
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Coupled active or standby router IP address (as the group is implemented by only two routers)
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State
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Protocol state (Disabled, Initial, Learn, Listen, Speak, Standby, Active)
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Virtual IP Address
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Virtual IP address used by this group
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Virtual MAC Address
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Virtual MAC address used by this group
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Generic Routing Encapsulation (GRE) Tunnel Interface
The following network layer Generic Routing Encapsulation (GRE) Tunnel Interface object, which represents a GRE Tunnel interface configuration in a network element, is primarily accessed by an IP Interface bound by its Contained Connection Termination Points attribute.
Table 2-14 Generic Routing Encapsulation (GRE) Tunnel Interface (ITunnelGRE)
Attribute Name
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Attribute Description
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Name
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Tunnel name
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Tunnel Destination and Source
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Tunnel destination and source IP addresses
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IP Address
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Primary IP address
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IP Interface State
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IP interface state (Unknown, Up, Down)
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IANA Type
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IANA type of the sub/layer
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Containing Termination Points
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Underlying termination points (connection or physical)
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Contained Connection Termination Points
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Bound Connection Termination Points
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Network Topology
The discovery of the Internet Protocol (IP) network layer is unsupported.
However, IP addresses and subnets are used for signature/test for the underlying MPLS and PPP layers topology discovery by searching for the existence of the local IP Address in any one hop away remote side's routing table. For more information see "Multiprotocol Label Switching "MPLS"" and "Point-to-Point Protocol "PPP" and High Level Data Link Control "HDLC"".
In particular, a comparison is made between the local and remote IP Addresses of IP Interfaces found under the same subnet.
Service Alarms
The following alarms are supported for this technology:
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All IP Interfaces Down/IP Interface Up
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GRE Tunnel Down/GRE Tunnel Up
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IP Interface Down/IP Interface Up
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HSRP Group Member Not Active/HSRP Group Member Active
Note
For a detailed description of these alarms and for information about correlation see the Cisco Active Network Abstraction Fault Management User Guide, 3.6.