Key benefits of ccie 400 101


The article at Testaimer.com going over http://www.testaimer.com/400-101-test is very comprehensive.

Q461. What is a reason to use DHCPv6 on a network that uses SLAAC? 

A. To get a record of the IPs that are used by the clients 

B. To push DNS and other information to the clients 

C. No reason, because there is no need for DHCPv6 when using SLAAC 

D. Because DHCPv6 can be used only in stateful mode with SLAAC to record the IPs of the clients 

E. Because DHCPv6 can be used only in stateless mode with SLAAC to record the IPs of the clients 

F. Because DHCPv6 is required to use first-hop security features on the switches 

Answer:

Explanation: 

SLAAC is by far the easiest way to configure IPv6 addresses, simply because you don’t have to configure any IPv6 address. With SLAAC, a host uses the IPv6 Neighbor Discovery Protocol (NDP) to determine its IP address and default routers. Using SLAAC, a host requests and listens for Router Advertisements (RA) messages, and then taking the prefix that is advertised to form a unique address that can be used on the network. For this to work, the prefix that is advertised must advertise a prefix length of 64 bits (i.e., /64). But the most significant of Stateless Address Autoconfiguration (SLAAC) is it provided no mechanism for configuring DNS resolver information.Therefore SLACC can be used along with DHCPv6 (Stateless) to push DNS and other information to the clients. 


Q462. Which statement about WAN Ethernet Services is true? 

A. Rate-limiting can be configured per EVC. 

B. Point-to-point processing and encapsulation are performed on the customer network. 

C. Ethernet multipoint services function as a multipoint-to-multipoint VLAN-based connection. 

D. UNIs can perform service multiplexing and all-in-one bundling. 

Answer:

Explanation: 

The MEF has defined a set of bandwidth profiles that can be applied at the UNI or to an EVC. A bandwidth profile is a limit on the rate at which Ethernet frames can traverse the UNI or the EVC. 

Reference: http://www.ciscopress.com/articles/article.asp?p=101367&seqNum=2 


Q463. DRAG DROP 

Drag each OSPF route-type identifier on the left to its description on the right. 

Answer: 


Q464. Refer to the exhibit. 

Which two statements are true? (Choose two.) 

A. This router is not 4-byte autonomous system aware. 

B. This router is 4-byte autonomous system aware. 

C. The prefix 10.100.1.1/32 was learned through an autonomous system number with a length of 4 bytes, and this router is 4-byte autonomous system aware. 

D. The prefix 10.100.1.1/32 was learned through an autonomous system number with a length of 4 bytes, and this router is not 4-byte autonomous system aware. 

E. The prefix 10.100.1.1/32 was originated from a 4-byte autonomous system. 

Answer: A,D 

Explanation: 

Prior to January 2009, BGP autonomous system (AS) numbers that were allocated to companies were 2-octet numbers in the range from 1 to 65535 as described in RFC 4271, A Border Gateway Protocol 4 (BGP-4). Due to increased demand for AS numbers, the Internet Assigned Number Authority (IANA) started to allocate four-octet AS numbers in the range from 65536 to 4294967295. RFC 5396, Textual Representation of Autonomous System (AS) Numbers, documents three methods of representing AS numbers. Cisco has implemented the following two methods: 

. Asplain — Decimal value notation where both 2-byte and 4-byte AS numbers are represented by their decimal value. For example, 65526 is a 2-byte AS number and 234567 is a 4-byte AS number. 

. Asdot — Autonomous system dot notation where 2-byte AS numbers are represented by their decimal value and 4-byte AS numbers are represented by a dot notation. For example, 65526 is a 2-byte AS number and 1.169031 is a 4-byte AS number (this is dot notation for the 234567 decimal number). 

Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_bgp/configuration/xe-3s/irg-xe-3s-book/irg-4byte-asn.html 


Q465. Refer to the exhibit. 

Which statement about the output is true? 

A. The flow is an HTTPS connection to the router, which is initiated by 144.254.10.206. 

B. The flow is an HTTP connection to the router, which is initiated by 144.254.10.206. 

C. The flow is an HTTPS connection that is initiated by the router and that goes to 144.254.10.206. 

D. The flow is an HTTP connection that is initiated by the router and that goes to 144.254.10.206. 

Answer:

Explanation: 

We can see that the connection is initiated by the Source IP address shown as 144.254.10.206. We also see that the destination protocol (DstP) shows 01BB, which is in hex and translates to 443 in decimal. SSL/HTTPS uses port 443. 


Q466. Which two statements about IS-IS wide metrics are true? (Choose two.) 

A. The wide metric is a 24-bit field. 

B. The maximum link metric is 16777215. 

C. R3 and R4 periodically advertise PNSP messages to synchronize the IS-IS database. 

D. IS-IS devices that are enabled with wide metrics can become neighbors with a device that uses standard metrics. 

E. The maximum link metric is 4261412864. 

F. The maximum path metric is 16777215. 

Answer: A,B 


Q467. Refer to the exhibit. 

The VLAN-to-MST mapping is shown. (Assume SW1 acts as root for all possible MST instances.) 

spanning-tree mst configuration name MST 

revision 2 

instance 0 vlan 1-200,301-4094 instance 1 vlan 201-300 

If this topology is deployed, which action is required for traffic to flow on VLAN 200 and 300? 

A. Map VLAN 300 to instance 0. 

B. Map VLAN 200 to instance 2. 

C. Move instance 0 root to SW2. 

D. Move instance 1 root to SW2. 

E. Map both VLANs to instance 2. 

Answer:


Q468. Which statement is true when using a VLAN ID from the extended VLAN range (1006–4094)? 

A. VLANs in the extended VLAN range can be used with VTPv2 in either client or server mode. 

B. VLANs in the extended VLAN range can only be used as private VLANs. 

C. STP is disabled by default on extended-range VLANs. 

D. VLANs in the extended VLAN range cannot be pruned. 

Answer:

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 


Q469. Which two types of traffic are blocked when the storm control threshold for multicast traffic is reached on a port? (Choose two.) 

A. BPDU 

B. OSPF 

C. CDP 

D. IS-IS 

E. LLDP 

Answer: B,D 


Q470. Refer to the exhibit. 

A Cisco Catalyst 6500 Series Switch experiences high CPU utilization. What can be the cause of this issue, and how can it be prevented? 

A. The hardware routing table is full. Redistribute from BGP into IGP. 

B. The software routing table is full. Redistribute from BGP into IGP. 

C. The hardware routing table is full. Reduce the number of routes in the routing table. 

D. The software routing table is full. Reduce the number of routes in the routing table. 

Answer:

Explanation: 

FIB TCAM Exception - If you try to install more routes than are possible into the FIB TCAM you will see the following error message in the logs: 

CFIB-SP-STBY-7-CFIB_EXCEPTION : FIB TCAM exception, Some entries will be software switched 

%CFIB-SP-7-CFIB_EXCEPTION : FIB TCAM exception, Some entries will be software switched. 

%CFIB-SP-STBY-7-CFIB_EXCEPTION : FIB TCAM exception, Some entries will be software switched. 

This error message is received when the amount of available space in the TCAM is exceeded. This results in high CPU. This is a FIB TCAM limitation. Once TCAM is full, a flag will be set and FIB TCAM exception is received. This stops from adding new routes to the TCAM. Therefore, everything will be software switched. The removal of routes does not help resume hardware switching. Once the TCAM enters the exception state, the system must be reloaded to get out of that state. You can view if you have hit a FIB TCAM exception with the following command: 

6500-2#sh mls cef exception status 

Current IPv4 FIB exception state = TRUE 

Current IPv6 FIB exception state = FALSE 

Current MPLS FIB exception state = FALSE 

When the exception state is TRUE, the FIB TCAM has hit an exception. 

The maximum routes that can be installed in TCAM is increased by the mls cef maximum-routes command. 

Reference: https://supportforums.cisco.com/document/59926/troubleshooting-high-cpu-6500-sup720