Ch 3 - IPv6 Review and RIPng Flashcards
Which of the following is the shortest valid abbreviation for FE80:0000:0000:0000:0 010:0000:0000:0123?
a. FE80::10::123
b. FE8::1::123
c. FE80:0:0:0:10::123
d. FE80::10:0:0:123
D. Inside a quartet, any leading 0s can be omitted, and one sequence of one or more quartets of all 0s can be replaced with “::”. The correct answer replaces the longer three-quartet sequence of 0s with ::.
An ISP has assigned prefix 3000:1234:5678::/48 to Company1. Which of the following terms would typically be used to describe this type of public IPv6 prefix?
a. Subnet prefix
b. ISP prefix
c. Global routing prefix
d. Registry prefix
C. The name of the prefix generally represents the group to which the prefix is given, with the exception of the term global routing. IANA assigns a prefix to a registry (registry prefix). The registry can assign a subset of that range as a prefix to an ISP (ISP prefix). That ISP then subdivides that range of addresses into prefixes and assigns a prefix to one of its customers (site prefix, also called global routing prefix). The enterprise network engineers then further subdivide the range, often with prefix length 64, into subnet prefixes.
Which of the following answers list either a protocol or function that can be used by a host to dynamically learn its own IPv6 address? (Choose two.)
a. Stateful DHCP
b. Stateless DHCP
c. Stateless autoconfiguration
d. Neighbor Discovery Protocol
A and C. IPv6 supports stateful DHCP, which works similarly to IPv4’s DHCP to dynamically assign the entire IP address. Stateless autoconfiguration also allows for the assignment by finding the prefix from some nearby router and calculating the Interface ID using the EUI-64 format. Stateless DHCP simply supplies the DNS server IP addresses, and NDP supplies Layer 2 mapping information.
Which of the following is helpful to allow an IPv6 host to learn the IP address of a default gateway on its subnet?
a. Stateful DHCP
b. Stateless RS
c. Stateless autoconfiguration
d. Neighbor Discovery Protocol
D. Stateless auto-configuration only helps a host learn and form its own IP address, but it does not help the host learn a default gateway. Stateless RS is not a valid term or feature. Neighbor Discovery Protocol (NDP) is used for several purposes, including the same purpose as ARP in IPv4, plus to learn configuration parameters such as a default gateway IP address.
Which of the following answers lists a multicast IPv6 address?
a. 2000::1:1234:5678:9ABC
b. FD80::1:1234:5678:9ABC
c. FE80::1:1234:5678:9ABC
d. FF80::1:1234:5678:9ABC
D. Global unicast addresses begin with 2000::/3, meaning that the first 3 bits match the value in hex 2000. Similarly, unique local addresses match FD00::/8, and link-local addresses match FE80::/10 (values that begin with FE8, FE9, FEA, and FEB hex). Multicast IPv6 addresses begin FF00::/8, meaning that the first two hex digits are F.
Router R1 has two LAN interfaces and three serial interfaces enabled for IPv6. All the interfaces use link-local addresses automatically generated by the router. Which of the following could be the link-local address of R1’s interface S0/0?
a. FEA0::200:FF:FE11:0
b. FE80::200:FF:FE11:1111
c. FE80::0213:19FF:FE7B:0:1
d. FEB0::211:11FF:FE11:1111
B. When created automatically, link-local addresses begin FE80::/64, because after the prefix of FE80::/10, the device builds the next 54 bits as binary 0s. Statically assigned link-local addresses simply need to conform to the FE80::/10 prefix. As a result, only two answers are candidates with a beginning quartet of FE80. Of these, only one has only hex 0s in the second, third, and fourth quartets, making answer B the only valid answer.
Router R1 has the following configuration. Assuming that R1’s F0/0 interface has a MAC address of 0200.0011.1111, what IPv6 addresses will R1 list for interface F0/0 in the output of the show ipv6 interface brief command? (Choose two.)
interface f0/0 ipv6 address 2345:0:0:8::1/64
a. 2345:0:0:8::1
b. 2345:0:0:8:0:FF:FE11:1111
c. FE80::FF:FE11:1111
d. FE80:0:0:8::1
A and C. The ipv6 address command does not list an eui-64 parameter, so R1 does not form its global unicast address using the EUI-64 format. However, it does form its link-local address using EUI-64. The show ipv6 interface brief command lists both the global unicast and link-local addresses in its output.
Router R1 lists the following output from a show command. Which of the following is true about R1?
R1# show ipv6 interface f0/0 FastEthernet0/0 is up, line protocol is up
IPv6 is enabled, link-local address is FE80::213:19FF:FE12:3456
No Virtual link-local address(es):
Global unicast address(es):
2000::4:213:19FF:FE12:3456, subnet is 2000:0:0:4::/64 [EUI]
Joined group address(es):
FF02::1
FF02::2
FF02::1:FF12:3456
a. R1’s solicited node multicast address is FF02::1:FF12:3456.
b. R1’s 2000::4:213:19FF:FE12:3456 address is a global unicast with all 128 bits
statically configured.
c. Address FF02::2 is R1’s solicited node multicast.
d. R1’s solicited node multicast, not listed in this output, would be FF02::213:19FF:FE12:3456.
A. The group addresses listed in the output are the all IPv6 hosts address (FF02::1), the all IPv6 routers address (FF02::2), and the solicited node address that is based on R1’s global unicast address (FF02::1:FF12:3456). Also, R1’s global unicast address is listed correctly in answer B, but the “[EUI]” notation implies that R1 derived the interface ID portion using EUI-64 conventions.
Which of the following features work the same in both RIPv2 and RIPng? (Choose three.)
a. Distance Vector Logic
b. Uses UDP
c. Uses RIP-specific authentication
d. Maximum useful metric of 15
e. Automatic route summarization
A, B, and D. RIPv2 and RIPng both use UDP, both use distance-vector logic, and both use the same metric, with the same maximum (15) and same metric that means infinity (16). RIPng does not perform automatic route summarization because IPv6 has no concept of a classful network. RIPng also uses the built-in IPv6 authentication mechanisms rather than a RIP-specific authentication such as RIPv2.
Router R1 currently has no configuration related to IPv6 or IPv4. The following configuration exists in a planning document, intended to be used to copy/paste into Router R1 to enable RIPng and IPv6 on interfaces Fa0/0 and S0/0/0. No other related configuration exists. Which of the following is true about RIPng on R1 after this configuration has been pasted into R1?
ipv6 unicast-routing
interface fa0/0
ipv6 rip one enable
ipv6 address 2000::1/64
interface s0/0/0
ipv6 address 2001::/64 eui-64
ipv6 rip one enable
a. RIPng will be enabled on no interfaces.
b. RIPng will be enabled on one interface.
c. RIPng will be enabled on two interfaces.
d. RIPng will advertise about prefixes connected to S0/0/0 and Fa0/0, but only send Updates on one interface.
B. The fact that the configuration will be copied/pasted into a router means that the order of the commands matters. In this case, the fact that the ipv6 rip one enable command precedes the ipv6 address command on interface f0/0 means that Cisco IOS will reject the first of these commands, therefore not enabling RIPng on F0/0. The correct order listed under S0/0/0 means that RIPng will be enabled on S0/0/0. As a result, RIPng on R1 will advertise about S0/0/0’s connected IPv6 prefixes, and send Updates on S0/0/0, but will do nothing related for F0/0.
T/F: In IPv6 per packet overhead is reduced because routers do not need to recalculate header checksums.
True.
T/F: IPv6 headers have a field that easily identifies packets that are sent over the same TCP/UDP connection.
True. The Flow Label field IDs them.
T/F: Like IPv4, IPv6 supports unicast, multicast and broadcast.
False. IPv6 does not support broadcast.
T/F: IANA assigns addresses to ICANN who in turn hands them out to the RIRs who give them to ISPs.
False.The process of global address assignment of IPv6 address space is managed by IANA. IANA is is a function ofICANN, a nonprofit privateAmericancorporation that oversees globalIP addressallocation,autonomous systemnumber allocation,root zonemanagement in theDomain Name System(DNS),media types, and otherInternet Protocol-related symbols andInternet numbers. IANA assigns one or more IPv6 address ranges to each RIR who in turn assign prefixes to the ISPs.
How many RIRs are there? Name them.
- ARIN, AfriNIC, APNIC, LACNIC, RIPE-NCC
How many hex digits are there in an IPv6 address?
- Each hex digit is 4 bits for a total of 128 bits for an IPv6 address.
What are the two rules for shortening an IPv6 address?
- Omit leading zeroes in any given quartet of hex digits 2. Represent one or more consecutive quartets of all hex 0s with ::, but only once.
If a quartet is 4 hex digits, how many quartets in an IPv6 address?
8
Which of these are valid shortenings of this IPv6 address: FE00:0000:0000:0001:0000:0000:0000:0056. A. FE00::1:0:0:0:56 B. FE00:0:0:1:::56 C. Neither D. Both
D. Both are valid.
T/F: IPv6 is a classful style of addressing.
False. Prefixes are very similar to VLSM and CIDR
What is the prefix of: 2000:1234:5678:9ABC:1111:1234:5678:9ABC/64 (the network address)
2000:1234:5678:9ABC::/64
What is the prefix of: 2000:1234:5678:9ABC:1111:1234:5678:9ABC/56 (the network address)
2000:1234:5678:9A00::/56 The last 8 bits are zero because they are host bits and not part of the prefix. Host bits are always written as zero in a network address.
T/F: When writing an IPv6 prefix, any bits after the prefix length number of bits are zero.
True.
T/F: When writing an IPv6 prefix, if the prefix length is not on a quartet boundary, write down the value for the entire quartet.
True.