Q101. Refer to the exhibit.
Which technology does the use of bi-directional BPDUs on all ports in the topology support?
A. RSTP
B. MST
C. Bridge Assurance
D. Loop Guard
E. Root Guard
F. UDLD
Answer: C
Explanation:
Spanning Tree Bridge Assurance
. Turns STP into a bidirectional protocol
. Ensures spanning tree fails “closed” rather than “open”
. If port type is “network” send BPDU regardless of state
. If network port stops receiving BPDU it’s put in BA-inconsistent state
Bridge Assurance (BA) can help protect against bridging loops where a port becomes designated because it has stopped receiving BPDUs. This is similar to the function of loop guard.
Reference: http://lostintransit.se/tag/convergence/
Q102. Which attribute is transported over an MPLS VPN as a BGP extended community?
A. route target
B. route distinguisher
C. NLRI
D. origin
E. local preference
Answer: A
Q103. Which two values are needed to configure NTP authentication? (Choose two.)
A. the encryption method
B. the key number
C. the burst mode
D. the key string
E. the Diffie-Hellman group
Answer: B,D
Q104. Which statement about VRRP is true?
A. It supports load balancing.
B. It can be configured with HSRP on a switch or switch stack.
C. It supports IPv4 and IPv6.
D. It supports encrypted authentication.
Answer: B
Explanation:
VRRP Limitations
. You can configure both HSRP and VRRP on a switch or switch stack. However, you cannot add a switch model that supports only one protocol to a stack that is configured for both protocols.
. The VRRP implementation on the switch does not support the MIB specified in RFC 2787.
. The VRRP implementation on the switch supports only text -based authentication.
. The switch supports VRRP only for IPv4.
Reference: http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750x_3560x/software/release/1 2-2_58_se/configuration/guide/3750xscg/swhsrp.html#pgfId-1107127
Q105. Which two fields reside in the initial CHAP challenge packet? (Choose two.)
A. the authentication name of the challenger
B. a random hash value generated by the device
C. the hashed packet type ID
D. the packet type ID in clear text
Answer: A,D
Explanation:
When a caller A dials in to an access server B, The Access server sends across the link an initial Type 1 authentication packet called a Challenge. This Challenge packet contains a randomly generated number, an ID sequence number to identify the challenge (sent in clear text) and the authentication name of the challenger.
Reference: http://www.rhyshaden.com/ppp.htm
Q106. Which two options are ways in which an OSPFv3 router handles hello packets with a clear address-family bit? (Choose two.)
A. IPv4 unicast packets are discarded.
B. IPv6 unicast packets are discarded.
C. IPv4 unicast packets are forwarded.
D. IPv6 unicast packets are forwarded.
Answer: A,D
Explanation:
A typical distance vector protocol saves the following information when computing the best path to a destination: the distance (total metric or distance, such as hop count) and the vector (the next hop). For instance, all the routers in the network in Figure 1 are running Routing Information Protocol (RIP). Router Two chooses the path to Network A by examining the hop count through each available path.
Since the path through Router Three is three hops, and the path through Router One is two hops, Router Two chooses the path through One and discards the information it learned through Three. If the path between Router One and Network A goes down, Router Two loses all connectivity with this destination until it times out the route of its routing table (three update periods, or 90 seconds), and Router Three re-advertises the route (which occurs every 30 seconds in RIP). Not including any hold-down time, it will take between 90 and 120 seconds for Router Two to switch the path from Router One to Router Three. EIGRP, instead of counting on full periodic updates to re-converge, builds a topology table from each of its neighbor's advertisements (rather than discarding the data), and converges by either looking for a likely loop-free route in the topology table, or, if it knows of no other route, by querying its neighbors. Router Two saves the information it received from both Routers One and Three. It chooses the path through One as its best path (the successor) and the path through Three as a loop-free path (a feasible successor). When the path through Router One becomes unavailable, Router Two examines its topology table and, finding a feasible successor, begins using the path through Three immediately.
Reference: http://www.cisco.com/c/en/us/support/docs/ip/enhanced-interior-gateway-routing-protocol-eigrp/16406-eigrp-toc.html
Q107. Under Cisco IOS Software, which two features are supported in RADIUS Change of Authorization requests? (Choose two.)
A. session identification
B. session reauthentication
C. session termination
D. host termination
Answer: A,C
Explanation:
CoA requests, as described in RFC 5176, are used in a pushed model to allow for session identification, host reauthentication, and session termination. The model comprises one request (CoA-Request) and two possible response codes.
Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/sec_usr_aaa/configuration/15-sy/sec-usr-aaa-15-sy-book/sec-rad-coa.html
Q108. Refer to the exhibit.
Which BGP feature allows R1 to instruct R2 which prefixes it is allowed to advertise to R1?
A. route refresh
B. Prefix-Based Outbound Route Filtering
C. distribute lists
D. prefix lists
Answer: B
Q109. Which two actions can you take to recover an interface in a errdisable state? (Choose two.)
A. Enable UDLD on the switch.
B. Enable errdisable recovery on the switch.
C. Execute the shutdown command on the interface, followed by the no shutdown command.
D. Remove the related commands from the configuration and reenter them.
E. Enable loop guard on the switch.
Answer: B,C
Q110. You are configuring a DMVPN hub to perform CBWFQ on a per-spoke basis. Which information is used to identify the spoke?
A. the NHRP network ID
B. the spoke tunnel source IP
C. the spoke tunnel interface IP address
D. the NHRP group
Answer: D