Implementing Cisco IP Routing
Question No: 221 – (Topic 7)
Using the rules for IPv6 addressing, how can the address 2031:0000:240F:0000:0000:09C0:123A:121B be rewritten?
A. 2031:0:240F::09C0:123A:121B B. 2031::240F::09C0:123A:121B C. 2031::240F:9C0::123A:121B D. 2031::240F:::09C0:123A:121B
Answer: A Explanation:
Leading zeros can be truncated. For example “0000 can be be just written as empty. In the above example :: indicates that it has multiple 0s in that location. Typically the IPv6 format can be written down in three ways 1) compressed, 2) uncompressed and 3) fully
uncompressed as shown below. All of the following are the same:
Question No: 222 – (Topic 7)
Refer to the exhibit. After configuring GRE between two routers running OSPF that are connected to each other via a WAN link, a network engineer notices that the two routers cannot establish the GRE tunnel to begin the exchange of routing updates. What is the reason for this?
Either a firewall between the two routers or an ACL on the router is blocking IP protocol number 47.
Either a firewall between the two routers or an ACL on the router is blocking UDP 57.
Either a firewall between the two routers or an ACL on the router is blocking TCP 47.
Either a firewall between the two routers or an ACL on the router is blocking IP protocol number 57.
Question No: 223 – (Topic 7)
Which option is one way to mitigate symmetric routing on an active/active firewall setup for TCP-based connections?
performing packet captures
disabling asr-group commands on interfaces that are likely to receive asymetric traffic
replacing them with redundant routers and allowing load balancing
disabling stateful TCP checks
Question No: 224 – (Topic 7)
Refer to the exhibit.
A network engineer has configured GRE between two IOS routers. The state of the tunnel interface is continuously oscillating between up and down. What is the solution to this problem?
Create a more specific static route to define how to reach the remote router.
Create a more specific ARP entry to define how to reach the remote router.
Save the configuration and reload the router.
Check whether the internet service provider link is stable
Question No: 225 – (Topic 7)
Which SNMP verification command shows the encryption and authentication protocols that are used in SNMPv3?
show snmp view
show snmp user
show snmp group
Question No: 226 – (Topic 7)
In a comparison of an IPv4 header with an IPv6 header, which three statements are true? (Choose three.)
An IPv4 header includes a checksum. However, an IPv6 header does not include one.
A router has to recompute the checksum of an IPv6 packet when decrementing the TTL.
An IPv6 header is half the size of an IPv4 header.
An IPv6 header has twice as many octets as an IPv4 header.
An IPv6 header is simpler and more efficient than an IPv4 header.
The 128-bit IPv6 address makes the IPv6 header more complicated than an IPv4 header.
Answer: A,D,E Explanation: Explanation
The image below shows the differences between an IPv4 header and an IPv6 header:
(Reference and a good resource, too:
Question No: 227 – (Topic 7)
Which IPv6 address correctly compresses the IPv6 unicast address 2001:0:0:0:0DB8:0:0:417A?
A. 2001:0DB8:417A B. 2001::0DB8::417A C. 2001:::0DB8::417A
D. 2001:0DB8:0:0:417A E. 2001::DB8:0:0:417A F. 2001:::0DB8:0:0:417A
Answer: E Explanation:
The point of this question is the about the different form of Ipv6 address.
The IPv6 address is 128 bits long, written as eight 16-bit pieces, separated by colons. Each piece is represented by four hexadecimal digits. You can compact multiple contiguous fields of zero even further. This is the exception to the rule that at least one digit must be present in every field. You can replace multiple fields of zeros with double colons (::).
Note that :: can replace only one set of contiguous zero fields. Multiple ::s would make the address ambiguous.
Question No: 228 – (Topic 7)
Refer to the exhibit.
Interface authentication must be configured.
The routing processes must be configured with an area ID.
IP unicast routing must be enabled.
IPv4 addresses must be applied to the interfaces.
Question No: 229 – (Topic 7)
Which statement describes the difference between a manually configured IPv6 in IPv4 tunnel versus an automatic 6to4 tunnel?
A manually configured IPv6 in IPv4 tunnel allows multiple IPv4 destinations.
An automatic 6to4 tunnel allows multiple IPv4 destinations.
A manually configured IPv6 in IPv4 tunnel does not require dual-stack (IPv4 and IPv6) routers at the tunnel endpoints.
An automatic 6to4 tunnel does not require dual-stack (IPv4 and IPv6) routers at the tunnel endpoints.
Answer: B Explanation: Explanation
An automatic 6to4 tunnel allows isolated IPv6 domains to be connected over an IPv4 network to remote IPv6 networks. The key difference between automatic 6to4 tunnels and manually configured tunnels is that the tunnel is not point-to-point; it is point-to-multipoint -gt; it allows multiple IPv4 destinations .
Manually 6to4 is point-to-point -gt; only allows one IPv4 destination.
Configuring 6to4 (manually and automatic) requires dual-stack routers (which supports both IPv4 amp; IPv6) at the tunnel endpoints because they are border routers between IPv4 amp; IPv6 networks.
(Reference: http://www.cisco.com/en/US/docs/ios/ipv6/configuration/guide/ip6- tunnel_ps6441_TSD_Products_Configuration_Guide_Chapter.html#wp1055515)
Question No: 230 – (Topic 7)
What is the IPv6 address FF02::2 used for?
all hosts in a local segment
all routers in a local segment
all hosts in a particular multicast group
all routers in an autonomous system
Answer: B Explanation:
To identify all nodes for the node-local and link-local scopes, the following multicast addresses are defined:
FF01::1 (node-local scope all-nodes address)
FF02::1 (link-local scope all-nodes address)
To identify all routers for the node-local, link-local, and site-local scopes, the following multicast addresses are defined:
FF01::2 (node-local scope all-routers address)
FF02::2 (link-local scope all-routers address)
FF05::2 (site-local scope all-routers address)