Q491. Which three options are results of the command no mpls ip propagate-ttl? (Choose three.)
A. It prevents the TTL from being copied from the IP header to the MPLS header.
B. It prevents the MPLS hops from being visible to a CE router when you perform a traceroute.
C. A fixed TTL value of 255 is used for the first label of the IP packet.
D. It prevents the TTL from being copied from the MPLS header back into the IP header.
E. MPLS hops remain visible on a CE router when you perform a traceroute.
F. A fixed TTL value of 1 is used for the first label of the IP packet.
Answer: A,B,C
Q492. Refer to the exhibit.
Notice that debug ip bgp updates have been enabled. What can you conclude from the debug output?
A. This is the result of the clear ip bgp 10.1.3.4 in command.
B. This is the result of the clear ip bgp 10.1.3.4 out command.
C. BGP neighbor 10.1.3.4 performed a graceful restart.
D. BGP neighbor 10.1.3.4 established a new BGP session.
Answer: A
Explanation:
If you enter the clear ip bgp out command for a BGP peer, that router resends its BGP prefixes to that peer. This does not cause a change in the best path on the receiving BGP peer. Hence, there is no change in the Table Version on that peer.
When you run the debug ip bgp updates on the receiving router, you see:
BGP(0): 10.1.3.4 rcvd UPDATE w/ attr: nexthop 10.1.3.4, origin i, metric 0, merged path 4, AS_PATH
BGP(0): 10.1.3.4 rcvd 10.100.1.1/32...duplicate ignored
The received update is recognized as a duplicate, so it is ignored and no best path change occurs.
Reference: http://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/116511-technote-tableversion-00.html
Q493. Which variable in an EEM applet is set when you use the sync yes option?
A. $_cli_result
B. $_result
C. $_string_result
D. $_exit_status
Answer: D
Explanation:
The CLI event detector screens CLI commands for a regular expression match. When a match is found, an event is published. The match logic is performed on the fully expanded CLI command after the command is successfully parsed and before it is executed. The CLI event detector supports three publish modes:
. Synchronous publishing of CLI events--The CLI command is not executed until the EEM policy exits, and the EEM policy can control whether the command is executed. The read/write variable, _exit_status, allows you to set the exit status at policy exit for policies triggered from synchronous events. If _exit_status is 0, the command is skipped, if _exit_status is 1, the command is run.
. Asynchronous publishing of CLI events--The CLI event is published, and then the CLI command is executed.
. Asynchronous publishing of CLI events with command skipping--The CLI event is published, but the CLI command is not executed.
Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/eem/command/eem-cr-
book/eem-cr-e1.html
Q494. Which two statements about Metro Ethernet services are true? (Choose two.)
A. EPL is a point-to-point service from one customer site to another across an MPLS
backbone.
B. EVPL is a multipoint service that emulates a LAN over an MPLS backbone.
C. EPLAN is a multipoint service that emulates a LAN over an MPLS backbone.
D. EVPL is a point-to-point service from one customer site to another across an MPLS backbone.
E. ELAN is a point-to-point service from one customer site to another across an MPLS backbone.
F. EVPL is a multipoint service with a root node that is suitable for multicast services.
Answer: A,B
Q495. DRAG DROP
Drag and drop the NHRP flag on the left to the corresponding meaning on the right.
Answer:
Q496. Refer to the exhibit.
Traffic from CE1 to CE2 is traveling through the core instead of through R1. All the PE routers have a similar configuration, and BGP peering and extended-community meshing are configured correctly.
Which configuration change routes the traffic through R1?
A)
B)
C)
D)
A. Exhibit A
B. Exhibit B
C. Exhibit C
D. Exhibit D
Answer: A
Q497. Refer to the exhibit.
Which BGP feature allows R1 to send R2 a list of prefixes that R2 is prevented from advertising to R1?
A. route refresh
B. Prefix-Based Outbound Route Filtering
C. distribute lists
D. prefix lists
Answer: B
Q498. Refer to the exhibit.
Why is the host unable to obtain an IP address?
A. IP source guard is configured on the switch port.
B. The DHCP server pool addresses are configured incorrectly.
C. DHCP requests are being blocked.
D. DHCP option 150 is disabled.
Answer: A
Q499. Which three statements about RIP timers are true? (Choose three.)
A. The default update timer is 30 seconds.
B. The default invalid timer is 180 seconds.
C. The default holddown timer is 180 seconds.
D. The default flush timer is 60 seconds.
E. The default scan timer is 60 seconds.
F. The default hello timer is 5 seconds.
Answer: A,B,C
Explanation:
The routing information protocol uses the following timers as part of its operation:
Update Timer
Invalid Timer
Flush Timer
Holddown Timer
Update Timer
The update timer controls the interval between two gratuitous Response Message. By default the value is 30 seconds. The response message is broadcast to all its RIP enabled interface.
Invalid Timer
The invalid timer specifies how long a routing entry can be in the routing table without being updated. This is also called as expiration Timer. By default, the value is 180 seconds. After the timer expires the hop count of the routing entry will be set to 16, marking the destination as unreachable.
Flush Timer
The flush timer controls the time between the route is invalidated or marked as unreachable and removal of entry from the routing table. By default the value is 240 seconds. This is 60 seconds longer than Invalid timer. So for 60 seconds the router will be advertising about this unreachable route to all its neighbors. This timer must be set to a higher value than the invalid timer.
Hold-down Timer
The hold-down timer is started per route entry, when the hop count is changing from lower value to higher value. This allows the route to get stabilized. During this time no update can be done to that routing entry. This is not part of the RFC 1058. This is Cisco's implementation. The default value of this timer is 180 seconds.
Reference: http://en.wikipedia.org/wiki/Routing_Information_Protocol#Timers