Cisco Active Network Abstraction Technology Support and Information Model Reference Manual, 3.6
Internet Protocol "IP"

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:

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:

IP Interface (IIPInterface)

IP Multiplexer Entry (IIPMuxEntry)

IP Interface Address (IIPInterfaceAddress)

IP Subnetwork (IPSubnet)

Routing Entity (IRoutingEntity)

Equivalent Routing Entry (IRoutingEntries)

Routing Entry (IRoutingEntry)

ARP Entity (IARPEntity)

ARP Entry (IARPEntry)

IP Address Pool (IIPPool)

IP Range Based Address Pool Entry (IIPRangeBasedIPPoolEntry)

IP Subnet Based Address Pool Entry (IIPSubnetBasedIPPoolEntry)

Hot Standby Router Protocol (HSRP) Group Entry (IHSRPGroupEntry)

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
Attribute Description

IP Address

Primary IP address

Subnetwork Mask

Primary IP subnetwork mask

IP Interface Addresses

Array of all IP Interface Addresses

Interface Name

Interface name

Interface Description

Interface description

IP Interface State

IP interface state (Unknown, Up, Down)

OSPF Interface Cost

2x10^9/<interface speed in BPS>

MTU

Maximum transmit units

Lookup Method

Lookup method (Route Table First, Host Table First)

Address Resolution Type

Address resolution type/s

ARP Timeout

ARP table entry aging timeout

Secured ARP

Secured ARP settings (Enable, Disable)

ICMP Mask Reply

Control message mask reply

IGMP Proxy

Group management proxy

HSRP Groups

Arrays of Hot Standby Router Protocol (HSRP) Group Entry (valid only for Cisco routers that implement HSRP)

IP Multiplexing Table

Array of IP Multiplexing Entries

IANA Type

IANA type of the sub/layer

Containing Termination Points

Underlying termination points (connection or physical)

Contained Connection Termination Points

Bound Connection Termination Points


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
Attribute Description

Termination Point

Virtual data link layer encapsulation

Destination IP Subnet

Destination IP subnet


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
Attribute Description

Type

IP address type (Primary, Secondary)

IP Subnet

IP subnetwork


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
Attribute Description

IP Address

IP address

Subnetwork Mask

IP subnetwork mask


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.

Table 2-5 Routing Entity (IRoutingEntity)

Attribute Name
Attribute Description

Routing Table

Array of Equivalent (Shared Destination) Routing Entries

ARP Entity

Address resolution entity (ARP Entity)

Routing Table Changes

Routing table changes count

Name

Routing entity name

Logical Sons

Array of all IP Interfaces 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
Attribute Description

Routing Entries

Array of Routing Entries (sharing a single destination)


Routing Entry

Table 2-7 Routing Entry (IRoutingEntry)

Attribute Name
Attribute Description

Destination IP Subnet

Final destination IP subnet

Next Hop IP Address

Next hop IP address

Type

Route entry type (Null, Other, Invalid, Direct, Indirect, Static)

Routing Protocol Type

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)

Outgoing Interface Name

Outgoing IP interface name


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
Attribute Description

ARP Table

Array of ARP Entries


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
Attribute Description

IP Address

Internet Protocol (IP) address

MAC Address

Media Access Control (MAC) address

Port

Data link layer (MAC) interface

Entry Type

ARP entry type (Null, Other, Invalid, Dynamic, Static)


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.

Table 2-10 IP Address Pool (IIPPool)

Attribute Name
Attribute Description

IP Address Pool Entries

Array of IP Range Based Address Pool Entries or IP Subnet Based Address Pool Entries

Name

IP addresses pool name

Index

IP addresses pool index


IP Range Based Address Pool Entry

Table 2-11 IP Range Based Address Pool Entry (IIPRangeBasedIPPoolEntry) 

Attribute Name
Attribute Description

Start IP Address

Start IP address of the IP address pool

End IP Address

End IP address of the IP address pool

Unused Addresses

Unused addresses count

Used Addresses

Used addresses count

Reserved Addresses

Reserved addresses count


IP Subnet Based Address Pool Entry

Table 2-12 IP Subnet Based Address Pool Entry (IIPSubnetBasedIPPoolEntry)

Attribute Name
Attribute Description

IP Subnet

IP Subnetwork of the IP address pool

Unused Addresses

Unused addresses count

Used Addresses

Used addresses count

Reserved Addresses

Reserved addresses count


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
Attribute Description

Group Number

Group number

Port Description

Port description

Priority

Priority from 0 (Lowest) to 255 (Highest) used for active router selection

Coupled Router

Coupled active or standby router IP address (as the group is implemented by only two routers)

State

Protocol state (Disabled, Initial, Learn, Listen, Speak, Standby, Active)

Virtual IP Address

Virtual IP address used by this group

Virtual MAC Address

Virtual MAC address used by this group


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
Attribute Description

Name

Tunnel name

Tunnel Destination and Source

Tunnel destination and source IP addresses

IP Address

Primary IP address

IP Interface State

IP interface state (Unknown, Up, Down)

IANA Type

IANA type of the sub/layer

Containing Termination Points

Underlying termination points (connection or physical)

Contained Connection Termination Points

Bound Connection Termination Points


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:

All IP Interfaces Down/IP Interface Up

GRE Tunnel Down/GRE Tunnel Up

IP Interface Down/IP Interface Up

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.