Answer: D 

Explanation: 

A manually configured tunnel is equivalent to a permanent link between two IPv6 domains over an IPv4 backbone. The primary use is for stable connections that require regular secure communication between two edge routers or between an end system and an edge router, or for connection to remote IPv6 networks. 

Reference: http://www.cisco.com/c/en/us/td/docs/ios/ipv6/configuration/guide/12_4t/ipv6_12_4t_book/i p6-tunnel.html 

Answer: C 

Explanation: 

In situations in which many clients use the same username to initiate an MP connection, or when interoperating with non-Cisco routers, you need to control the order in which the bundle name is created. It is necessary to configure the access server to create a bundle name based on the endpoint discriminator first, the username second, or both. The endpoint discriminator identifies the system transmitting the packet and advises the network access server (NAS) that the peer on this link could be the same as the peer on another existing link. Because every client has a unique endpoint discriminator, only multiple links from the same client are bundled into a single unique MP connection. For example, consider when two PC clients initiate a multilink connection to an access server using the same username. If the multilink bundle name is established based on the endpoint discriminator first, then on the username or on both, the NAS can accurately bundle the links from each client using the endpoint discriminator as a bundle name. This bundle name is unique to the peer system transmitting the packet. 

Reference: http://www.cisco.com/c/en/us/support/docs/wan/point-to-point-protocol-ppp/10238-mppp-bundle-name.html 

Answer: B 

Explanation: 

A filter can be applied to limit the capture to desired traffic. Define an Access Control List (ACL) within config mode and apply the filter to the buffer: 

ip access-list extended BUF-FILTER 

permit ip host 192.168.1.1 host 172.16.1.1 

permit ip host 172.16.1.1 host 192.168.1.1 

monitor capture buffer BUF filter access-list BUF-FILTER 

Reference: http://www.cisco.com/c/en/us/support/docs/ios-nx-os-software/ios-embedded-packet-capture/116045-productconfig-epc-00.html 

Answer: B 

Explanation: 

One of the most commonly used identifiers in SNMP-based network management applications is the Interface Index (ifIndex) value. IfIndex is a unique identifying number associated with a physical or logical interface. For most software, the ifIndex is the name of the interface. Although relevant RFCs do not require that the correspondence between particular ifIndex values and their interfaces be maintained across reboots, applications such as device inventory, billing, and fault detection depend on this correspondence. Consider a situation where a simple monitoring software (like MRTG) is polling the interface statistics of the router specific serial interface going to the internet. 

As an example, you could have these conditions prior to re-initialization: 

physical port ifIndex 

ethernet port 

tokenring port 

2 

serial port 

3 

Therefore, the management application is polling the ifIndex 3, which corresponds to the serial port. 

After the router re-initialization (reboot, reload and so on) the conditions change to something similar to this: 

physical port 

ifIndex 

ethernet port 

3 

tokenring port 

1 

serial port 

2 

The management application continues polling the ifIndex 3, which corresponds now to the ethernet port. Therefore, if the management application is not warned by a trap, for example, that the router has been rebooted, the statistics polled could be completely wrong. 

Reference: http://www.cisco.com/c/en/us/support/docs/ip/simple-network-management-protocol-snmp/28420-ifIndex-Persistence.html 

Answer: A,B,D 

Explanation: 

Like IGMP snooping, MLD snooping performs multicast router discovery, with these characteristics: 

. Ports configured by a user never age out. 

. Dynamic port learning results from MLDv1 snooping queries and IPv6 PIMv2 packets. 

. If there are multiple routers on the same Layer 2 interface, MLD snooping tracks a single multicast router on the port (the router that most recently sent a router control packet). 

. Dynamic multicast router port aging is based on a default timer of 5 minutes; the multicast router is deleted from the router port list if no control packet is received on the port for 5 minutes. 

. IPv6 multicast router discovery only takes place when MLD snooping is enabled on the switch. 

Reference: https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750/software/release/12-2_55_se/configuration/guide/scg3750/swv6mld.pdf 

Answer: A 

Answer: A,B,C 

Explanation: 

The virtual MAC address in GLBP is 0007.b400.xxyy where xx is the GLBP group number and yy is the different number of each gateway (01, 02, 03…). One of the routers in a GLBP group is elected as an AVG – Active Virtual Gateway. There is only one active AVG in a group, and its task is to respond to ARP requests sent to the virtual gateway IP address replying different virtual MAC addresses in response packets. GLBP allows the configured virtual IP address to be used on a physical interface. By default, the GLBP gateway preemptive scheme is disabled. A backup virtual gateway can become the AVG only if the current AVG fails, regardless of the priorities assigned to the virtual gateways. 

Answer: D 

Explanation: 

Enabling VTP pruning on a VTP server enables pruning for the entire management domain. Making VLANs pruning-eligible or pruning-ineligible affects pruning eligibility for those VLANs on that device only (not on all switches in the VTP domain). VTP pruning takes effect several seconds after you enable it. VTP pruning does not prune traffic from VLANs that are pruning-ineligible. VLAN 1 and VLANs 1002 to 1005 are always pruning-ineligible; traffic from these VLANs cannot be pruned. Extended-range VLANs (VLAN IDs higher than 1005) are also pruning-ineligible. 

Reference: http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3550/software/release/12-1_13_ea1/configuration/guide/3550scg/swvtp.html#wpxref48156 

Answer: A,C 

Explanation: 

MPLS VPN functionality is enabled at the edge of an MPLS network. The PE router performs these tasks: . 

Exchanges routing updates with the CE router . 

Translates the CE routing information into VPN version 4 (VPNv4) routes . 

Exchanges VPNv4 routes with other PE routers through the Multiprotocol Border Gateway Protocol (MP-BGP) 

A PE router binds a label to each customer prefix learned from a CE router and includes the label in the network reachability information for the prefix that it advertises to other PE routers. When a PE router forwards a packet received from a CE router across the provider network, it labels the packet with the label learned from the destination PE router. When the destination PE router receives the labeled packet, it pops the label and uses it to direct the packet to the correct CE router. Label forwarding across the provider backbone is based on either dynamic label switching or traffic engineered paths. A customer data packet carries two levels of labels when traversing the backbone 

Reference: http://www.cisco.com/c/en/us/td/docs/routers/asr9000/software/asr9k_r4-2/lxvpn/configuration/guide/vcasr9kv342/vcasr9k42v3.html 

Answer: A,B