Review Questions
Answer the following questions, and then refer to Appendix B, "Answers to Review Questions," for the answers.
For each of the fields in the following table, give the field's length and indicate whether it is used in the IPv4 header or IPv6 header.
Field
Length in Bits
IPv4 Header
IPv6 Header
Type of Service
Identification
Version
Time to live
Header checksum
Header length
Traffic Class
Total Length
Flow Label
Flags
Padding
Extension header
Payload Length
Protocol Number
Hop Limit
Source Address
Destination Address
Options
Next Header
Fragment Offset
List the fields removed from the IPv4 header.
What new field is added in the IPv6 header?
Describe the use of the Next Header field in the IPv6 header.
List the extension headers that may be placed after the basic IPv6 header, and place them in the order they must appear.
What is mandatory with UDP when used over IPv6?
What is recommended as a mechanism for nodes in IPv6 to avoid fragmentation?
What are IPv6's minimum MTU and recommended minimum MTU?
What are the three representations of IPv6 addresses?
Compress the following IPv6 addresses into the shortest form possible.
Preferred Representation
Compressed Representation
A0B0:10F0:A110:1001:5000:0000:0000:0001
0000:0000:0000:0000:0000:0000:0000:0001
2001:0000:0000:1234:0000:0000:0000:45FF
3ffe:0000:0010:0000:1010:2a2a:0000:1001
3FFE:0B00:0C18:0001:0000:1234:AB34:0002
FEC0:0000:0000:1000:1000:0000:0000:0009
FF80:0000:0000:0000:0250:FFFF:FFFF:FFFF
Describe the IPv6 address representation for URL.
List the three kinds of addresses in the IPv6 addressing architecture.
For each of the following address types, find the IPv6 prefix and write the address in the compressed representation.
Unspecified
Loopback
IPv4-compatible IPv6
Link-local
Site-local
Multicast
Solicited-node multicast
Aggregatable global unicastWhat is a link-local address?
What is similar to the site-local address in IPv4?
In the following table, list the solicited-node multicast address that corresponds to each unicast address.
Unicast Address
Solicited-Node Multicast Address
A0B0:10F0:A110:1001:5000:0000:0000:0001
2001:0000:0000:1234:0000:0000:0000:45FF
3ffe:0000:0010:0000:1010:2a2a:0000:1001
3FFE:0B00:0C18:0001:0000:1234:AB34:0002
FEC0:0000:0000:1000:1000:0000:0000:0009
Give the length in bits of the host and site parts of an aggregatable global unicast IPv6 address.
What three prefixes are assigned by IANA and are available as public addresses in IPv6?
What is the Cisco IOS Software command to enable IPv6 on a Cisco router?
What protocol ID is used for IPv6 in Ethernet frames?
Explain how IPv6 multicast addresses are mapped over Ethernet.
Generate IPv6 interface IDs (in EUI-64 format) from the following Ethernet link-layer addresses.
Ethernet Link-Layer Address
IPv6 Interface ID
00:90:27:3a:9e:9a
00:90:27:3a:8d:c3
00:00:86:4b:fe:ce
What command assigns one IPv6 address to an interface using EUI-64 format?
What is the goal of the path MTU discovery mechanism?