You are working at a large service provider supporting the core MPLS network. You have
determined that a line card in one of the core routers has failed. Which two steps should you take
before requesting that a technician be dispatched to the location to replace the card? (Choose
two.)

You are working at a service provider supporting the core network. While proactively monitoring
syslog, you notice that two power supplies have failed on one of the core routers. The router has
five power hot-swappable supplies in total. Three are required to be working to support the power
draw of the router. At this point, the router is still functioning correctly. It is now several hours
before peak traffic will be present on the network. The next safe time for performing physical
maintenance is not until after the peak traffic window. Which two steps should you take to
minimize network impact during peak traffic? (Choose two.)

Users have complained recently about their experience with a collaboration tool that is being used
on different international locations on your network. The collaboration tool uses IP precedence of
“4” for all the traffic that runs over your network. Upon investigating the problem, you noticed that
the tool worked fine most of the time. You observed that video frames would freeze occasionally
for a short time, and some collaboration features had slow responses. The IT department has
been engaged, and they believe that the problem is with the network transport. You tried end-toend extended pings by using the ToS value of 128 and noticed a high round-trip time on some of
the ping packets. To the best of your knowledge, all the routers in the forwarding path are
distributed architecture, hardware-based forwarding devices, and the entire path is QoS-enabled.
What should be the next three steps in identifying the root cause? (Choose three.)

A large IPTV service provider primarily uses multicast for delivering IPTV services to its
customers. The service provider delivers digital television channels to home viewers by using a
set-top box as a home appliance and controls this device through its video middleware. Each
video channel uses a unique multicast group address. Recently, some channels have higher
channel change times; to alleviate this problem, a number of solutions were discussed between
the operations and engineering groups. Adding to the complexity of the issue is the fact that the
business has been growing, and the service provider made acquisitions both in its home operating

market and new geographic locations. These changes have made the management of source and
group addresses a major concern. The engineering team thinks that using static joins for popular
channels at the edge routers and moving away from Sparse Mode to SSM-based forwarding will
improve performance issues.
What are two valid concerns for the operations group? (Choose two.)

A service provider allowed private IPv6 BGP peering with a university research network. On
receiving IPv6 traffic, one Cisco 12000 Series Router that is located in the path of IPv6 traffic
experienced high CPU use on its single-port OC192 line card that caused OSPF adjacency to
drop on its port. Prior to receiving IPv6 traffic, this OC192 port was passing approximately 1 Gb of
IPv4 traffic without any noticeable CPU use. What are two possible reasons for this performance
problem? (Choose two.)

In addition to a DoS attack, what are three reasons that cause an increase in the CPU use of a
route processor or the line card of a router? (Choose three.)

You have just received a major threshold alert from your performance management system for two
of the three core routers. The alert states that “Link utilization between these two core routers has
exceeded 80% threshold mark.” Which three alarms or notifications should you look for in the fault
management system to help isolate the problem? (Choose three.)

Which three features are used to mitigate or protect DoS attacks that are targeted at a router?
(Choose three.)

A Tier 2 ISP network provides Internet connectivity to residential and business customers. The
Tier 2 ISP uses Internet transit service from Tier 1 ISPs at different locations. Lately, the link
utilization on a few core links of the Tier 2 ISP has increased to unacceptable levels, while a
significant part of the core network has low utilization. Which two of the following methods should
be used to alleviate this problem without deploying additional links? (Choose two.)

An ISP is concerned about DoS attacks that tend to starve out legitimate flows by generating
malicious traffic. A number of techniques are being considered for the network edge. What are
three correct statements regarding preventive measures against DoS attacks? (Choose three.)