Answer: A,C 

Answer: A 

Explanation: 

Configuring NetFlow 

Perform the following task to enable NetFlow on an interface. SUMMARY STEPS 

1. enable 

2. configure terminal 

3. interface type number 

4. ip flow {ingress | egress} 

5. exit 

6. Repeat Steps 3 through 5 to enable NetFlow on other interfaces. 

7. end 

DETAILED STEPS 

Command or Action 

Purpose 

Step 1 

enable 

Example: 

Router> enable Enables privileged EXEC mode. . 

Enter your password if prompted. 

Step 2 

configure terminal Example: 

........

Example: 

Router(config)# interface ethernet 0/0 

Specifies the interface that you want to enable NetFlow on and enters interface configuration mode. 

Step 4 

ip flow {ingress | egress} 

Example: 

Router(config-if)# ip flow ingress 

Enables NetFlow on the interface. 

. ingress—Captures traffic that is being received by the interface 

. egress—Captures traffic that is being transmitted by the interface 

Step 5 

exit 

Example: 

Router(config-if)# exit 

(Optional) Exits interface configuration mode and enters global configuration mode. 

Note 

You need to use this command only if you want to enable NetFlow on another interface. 

Step 6 

Repeat Steps 3 through 5 to enable NetFlow on other interfaces. 

This step is optional. 

Step 7 

end 

Example: 

Router(config-if)# end Exits the current configuration mode and returns to privileged EXEC mod 

Reference: http://www.cisco.com/c/en/us/td/docs/ios/netflow/configuration/guide/12_2sr/nf_12_2sr_boo k/cfg_nflow_data_expt.html 

Answer: D 

Explanation: 

Ethernet-over-MPLS (EoMPLS) provides a tunneling mechanism for Ethernet traffic through an MPLS-enabled L3 core and encapsulates Ethernet protocol data units (PDUs) inside MPLS packets (using label stacking) to forward them across the MPLS network. Another technology that more or less achieves the result of AToM is L2TPV3. In the case of L2TPV3 Layer 2 frames are encapsulated into an IP packet instead of a labelled MPLS packet. 

Reference: http://www.cisco.com/c/en/us/td/docs/routers/asr9000/software/asr9k_r4-3/lxvpn/configuration/guide/lesc43xbook/lesc43p2ps.html 

Answer: A,D 

Answer: A,B 

Explanation: 

When dealing with the possibility of routing updates making their way back into an AS, BGP relies on the information in the AS_path for loop detection. An update that tries to make its way back into the AS it was originated from will be dropped by the border router. With the introduction of route reflectors, there is a potential for having routing loops within an AS. A routing update that leaves a cluster might find its way back inside the cluster. Loops inside the AS cannot be detected by the traditional AS_path approach because the routing updates have not left the AS yet. BGP offers two extra measures for loop avoidance inside an AS when route reflectors are configured. 

Using an Originator ID 

The originator ID is a 4-byte, optional, nontransitive BGP attribute (type code 9) that is created by the route reflector. This attribute carries the router ID of the originator of the route in the local AS. If, because of poor configuration, the update comes back to the originator, the originator ignores it. 

Using a Cluster List 

The cluster list is an optional, nontransitive BGP attribute (type code 10). Each cluster is represented with a cluster ID. 

A cluster list is a sequence of cluster IDs that an update has traversed. When a route reflector sends a route from its clients to nonclients outside the cluster, it appends the local cluster ID to the cluster list. If the route reflector receives an update whose cluster list contains the local cluster ID, the update is ignored. This is basically the same concept as the AS_path list applied between the clusters inside the AS. 

Reference: http://borg.uu3.net/cisco/inter_arch/page11.html 

Answer: B 

Answer: B 

Explanation: 

The local routes have the administrative distance of 0. This is the same adminstrative distance as connected routes. However, when you configure redistributed connected under any routing process, the connected routes are redistributed, but the local routes are not. This behavior allows the networks to not require a large number of host routes, because the networks of the interfaces are advertised with their proper masks. These host routes are only needed on the router that owns the IP address in order to process packets destined to that IP address. 

It is normal for local host routes to be listed in the IPv4 and IPv6 routing table for IP addresses of the router's interfaces. Their purpose is to create a corresponding CEF entry as a receive entry so that the packets destined to this IP address can be processed by the router itself. These routes cannot be redistributed into any routing protocol. 

Reference: http://www.cisco.com/c/en/us/support/docs/ip/ip-routing/116264-technote-ios-00.html 

Answer: D 

Explanation: 

As the iBGP learned routes are reflected, routing information may loop. The route reflector model has the following mechanisms to avoid routing loops: 

. Originator ID is an optional, nontransitive BGP attribute. It is a 4-byte attributed created by a route reflector. The attribute carries the router ID of the originator of the route in the local autonomous system. Therefore, if a misconfiguration causes routing information to come back to the originator, the information is ignored. 

. Cluster-list is an optional, nontransitive BGP attribute. It is a sequence of cluster IDs that the route has passed. When a route reflector reflects a route from its clients to nonclient peers, and vice versa, it appends the local cluster ID to the cluster-list. If the cluster-list is empty, a new cluster-list is created. Using this attribute, a route reflector can identify if routing information is looped back to the same cluster due to misconfiguration. If the local cluster ID is found in the cluster-list, the advertisement is ignored. 

Reference: http://www.cisco.com/c/en/us/td/docs/ios/12_2/ip/configuration/guide/fipr_c/1cfbgp.html 

Answer: A,B 

Answer: A