Cisco (300-410-ENARSI) Exam Questions And Answers page 17

In OSPF point-to-multipoint mode, the routers will automatically identify each neighbor. The election of a designated router (DR) and backup designated router (BDR) are not required. This RFC compliant mode of operation is commonly found in partial mesh topologies, such as hub-and-spoke designs. In the diagram shown in the scenario, router A is the hub.
The frame relay serial interface has one DLCI to each spoke location. DLCI 221 is used by router A to communicate with router C and DLCI 222 is used to communicate with router B. On router A's serial interface, point-to-multipoint mode is enabled with the ip ospf network configuration command. The following is the syntax of the ip ospf network command:
ip ospf network [{broadcast | nonbroadcast | point-to-multipoint | point-to-multipoint nonbroadcast}]

The command parameters are as follows:
• broadcast - This mode enables the interface to emulate a LAN. This mode requires a full or partial mesh topology.
• nonbroadcast - This RFC 2328 compliant mode is also referred to as NBMA mode. The neighbors must be statically configured.
• point-to-multipoint - This RFC 2328 compliant mode is used in partial mesh topologies, such as hub-and-spoke. Routers use additional LSAs to discover neighboring routers instead of manually defining DRs and BDRs. The hub router floods link state updates (LSUs) by duplicating the update to be sent to each routers using the respective DLCI.
• point-to-multipoint nonbroadcast - This is a Cisco extension to the point-to-multipoint mode.
This mode is useful when the frame relay virtual circuits do not support broadcast traffic. Neighbors are manually defined.
There is no point-to-point parameter for the ip ospf command. Creating a point-to-point configuration differs in that the point-to-point parameter is executed as a parameter of the command that creates the subinterface that hosts the point-to-point connection as shown below:
Router(config)# interface serial 0.1 point-to-point

When configuring a serial interface without sub-interfaces, OSPF will check the encapsulation to determine the network type. HDLC and PPP default to point-to-point while Frame-Relay encapsulation defaults to nonbroadcast.
The frame-relay map command identifies the mapping between the Layer 3 address (IP address) and the Layer 2 address (DLCI). The frame relay virtual circuits from the hub router are identified as supporting broadcast traffic by using the frame-relay map command with the broadcast keyword.
Objective:
Layer 2 Technologies
Sub-Objective:
Explain Frame Relay
Cisco > Home > Support > Support Technology > Support > IP Routing > Configure > Configuration Examples and Technotes > Initial Configurations for OSPF over Frame Relay Subinterfaces
Cisco > Cisco IOS Wide-Area Networking Command Reference > frame-relay lapf n201 through fr-atm connect dlci > frame-relay map

The command ip nat inside source list 7 serial0 overload specifies the following:
• The translation should occur in the interface specified as inside.
• It should only be done for inside IP addresses that are specified in access list number 7.
• The IP address that inside addresses should be translated to belongs to the Serial0 interface.
• The translated IP address should be shared by all, as indicated by the overload keyword.
The command ip nat inside identifies the inside interface. In this case, it indicates the one on which translation will take place.
The command ip nat outside identifies the outside interface, which can be configured for translation. However, it has not been configured for translation in this scenario.
The commands below define the inside IP addresses that are allowed to be translated:
access-list 7 permit 10.10.10.0 0.0.0.31
access-list 7 permit 10.10.20.0 0.0.0.31

Objective:
Infrastructure Services
Sub-Objective:
Configure and verify IPv4 Network Address Translation (NAT)
Home > Support >Troubleshooting Technotes > Configuring Network Address Translation: Getting Started
Cisco > Cisco IOS IP Application Services Command Reference > ip nat inside source

The interface ID of the subinterface created to host the virtual network named red will be FastEthernet1/0/0.3, and the IP address will be 10.1.1.1.
When a virtual routing and forwarding (VRF) instance is defined, it will have a name and a tag number. The tag number is used by the router to dynamically create a subinterface on the specified physical interface of the EVN trunk. The tag number is appended to the physical interface ID. Since the virtual network (vnet) trunk was defined as FastEthernet1/0/0, the subinterface for vrf red will be FastEthernet1/0/0.3. All subinterfaces on the trunk will use the same IP address as the physical interface defined as the trunk.
Easy virtual networking (EVN) is a technology that allows for multiple logical networks to use the same physical infrastructure. EVN trunks carry the traffic of multiple VRFs. While the subinterfaces dedicated to each VRF use the same IP address (that of the physical interface of the EVN trunk), no IP address conflicts ever occur because each VRF maintains its own routing and forwarding tables, and while on the trunk, each uses a VRF tag to separate the traffic from each VRF.
Objective:
VPN Technologies
Sub-Objective:
Describe Easy Virtual Networking (EVN)
Cisco > Easy Virtual Network Configuration Guide, Cisco IOS XE Release 3S > Overview of Easy Virtual Network

The R2 router will not form adjacencies with neighboring routers in the area if the area IDs do not match. The area keyword in the network command is missing from the initial router R2 configuration. The correct command would be:
R2(config)# network 192.16.31.0 0.0.0.255 area 1

Secondly, the subnets keyword should be used in the redistribute command to ensure that all of the subnets in the 10.0.0.0/8 are redistributed into OSPF. For example, you would use the following commands to redistribute EIGRP autonomous system (AS) 50 networks and subnetworks into OSPF with a metric of 100 and advertise them as external Type 1 routes:
R2(config)# router ospf
R2(config-router)# redistribute eigrp 50 metric 100 metric-type 1

The complete syntax for the redistribute command when used in OSPF is as follows:
redistribute protocol [process-id] [metric metric-value] [metric-type type-value] [subnets]

The command parameters are:
• protocol - Identifies the source protocol, such as BGP, connected, EIGRP, IGRP, ISIS, OSPF, static, or rip.
• process-id - Depending on the routing protocol, identifies the source autonomous system number or process ID.
• metric - Identifies the seed metric for the redistributed route. The default is 0.
• metric-type - For OSPF, it identifies the redistributed routes as either external Type 1 or Type 2 routes. The default is Type 2.
• subnets - Optional keyword for use with OSPF to indicate that the scope of the networks to be redistributed also includes subnets.
Objective:
Layer 3 Technologies
Sub-Objective:
Configure and verify redistribution between any routing protocols or routing sources
Cisco > Cisco IOS IP Routing: Protocol-Independent Command Reference > redistribute (ip)

The value 4294967295 in the debug ip eigrp output represents the unreachable metric for EIGRP. This means that the network has become unavailable and cannot be reached. In this output, the M represents the local metric, and the SM represents the metric that was reported by the neighbor that advertised the network to the local router.
The administrative distance (AD) for internal EIGRP is 90.
The link characteristics that are used in the EIGRP calculation are shown following the dash after the M and SM values (1657856 4294967295). By default, EIGRP only uses bandwidth and delay in its calculation.
Objective:
Layer 3 Technologies
Sub-Objective:
Describe and optimize EIGRP metrics
Cisco > Cisco IOS Debug Command Reference > debug h225 asn1 through debug ip ftp > debug ip eigrp