Examkin

IPv6 Addressing and Prefixes

38 soru

Tüm türler38Çoktan seçmeli18Çoklu seçim10Eşleştirme10
Soru 1Soru →

A network administrator is configuring a router interface for IPv6 stateless address autoconfiguration (SLAAC) using EUI-64. The interface is assigned the IPv6 prefix 2001:db8:cafe:10::/642001:\text{db8}:\text{cafe}:10::/64 and has a MAC address of B4A9.5A12.3456\text{B4A9.5A12.3456}. Which complete IPv6 global unicast address will be generated for this interface?

Cevabı ve açıklamayı göster

Cevap: 2001:db8:cafe:10:b6a9:5aff:fe12:3456

Cevap

2001:db8:cafe:10:b6a9:5aff:fe12:3456
The address ending in 'b6a9:5aff:fe12:3456' is correct because EUI-64 splits the MAC address B4:A9:5A:12:34:56 into two equal parts, inserts the 16-bit hex value FFFE into the middle, and flips the 7th bit of the first byte (changing 0xB4, which is 1011 0100 binary, into 0xB6, which is 1011 0110 binary).

Adım Adım Çözüm

1
Split the MAC address into two 24-bit halves and insert FFFE in the middle.
The MAC address B4:A9:5A : 12:34:56 becomes B4A9:5AFF:FE12:3456.
EUI-64 expands a 48-bit MAC address into a 64-bit interface identifier by inserting the 16-bit hex value FFFE between the OUI and the NIC specific serial number.
2
Invert the 7th bit (Universal/Local bit) of the first byte.
First byte 0xB4 in binary is 1011 0100. Inverting the 7th bit gives 1011 0110, which is 0xB6. The interface ID becomes b6a9:5aff:fe12:3456.
RFC 4291 requires flipping the 7th bit of the first byte to indicate universal scope for IEEE MAC-derived interface identifiers.
3
Combine the /64 network prefix with the generated 64-bit interface identifier.
2001:db8:cafe:10:b6a9:5aff:fe12:3456.
The full IPv6 address is constructed by appending the EUI-64 interface ID to the assigned /64 network subnet prefix.

Anahtar Kavram

EUI-64 Interface Identifier Generation
Tahmini Süre:1m 15s
Soru 2Soru →

Match each IPv6 address scope or functional type on the left with its standardized reserved prefix or address range on the right.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

Global Unicast
Link-Local
Unique Local
Multicast
Loopback

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

Global Unicast matches 2000::/32000::/3; Link-Local matches fe80::/10\text{fe80}::/10; Unique Local matches fc00::/7\text{fc00}::/7; Multicast matches ff00::/8\text{ff00}::/8; Loopback matches ::1/128::1/128.
Each IPv6 address type is mapped directly to its standard RFC 4291 prefix definition: Global Unicast to 2000::/32000::/3, Link-Local to fe80::/10\text{fe80}::/10, Unique Local to fc00::/7\text{fc00}::/7, Multicast to ff00::/8\text{ff00}::/8, and Loopback to ::1/128::1/128.

Adım Adım Çözüm

1
Identify IPv6 unicast address scopes.
Global Unicast is assigned 2000::/32000::/3, Link-Local is assigned fe80::/10\text{fe80}::/10, and Unique Local is assigned fc00::/7\text{fc00}::/7.
RFC 4291 partitions the IPv6 address space into well-defined unicast functional scopes.
2
Identify special and multicast IPv6 prefixes.
Multicast addresses use ff00::/8\text{ff00}::/8, and the single host loopback address is ::1/128::1/128.
Multicast replaces IPv4 broadcasts and uses the ff00::/8\text{ff00}::/8 prefix, while ::1/128::1/128 is reserved exclusively for loopback operations.

Anahtar Kavram

IPv6 Reserved Prefixes and Address Scopes
Soru 3Soru →

Match each IPv6 addressing scenario or network description on the left with its corresponding prefix length or field bit length on the right.

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Öğeler

The standard prefix length required for an enterprise end-user LAN subnet to support Stateless Address Autoconfiguration (SLAAC)
The typical prefix length allocated by a Regional Internet Registry (RIR) or ISP to an enterprise customer site
The RFC 6164 recommended prefix length for point-to-point inter-router link interfaces
The standard bit length allocated strictly for the host Interface Identifier (ID) portion of a Global Unicast Address

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

The SLAAC end-user LAN subnet requires a /64 prefix length; the enterprise customer ISP allocation is typically a /48 prefix length; the point-to-point inter-router link uses a /127 prefix length; and the host Interface Identifier occupies 64 bits.
Each scenario maps directly to IPv6 architectural conventions: SLAAC requires a /64 prefix, enterprise sites typically receive a /48 prefix, point-to-point inter-router links use /127 per RFC 6164, and the host Interface ID portion is 64 bits.

Adım Adım Çözüm

1
Analyze SLAAC prefix length requirements.
SLAAC requires a /64 prefix length.
SLAAC relies on receiving a /64 prefix advertisement in ICMPv6 Router Advertisement (RA) messages to combine with a 64-bit Interface ID.
2
Determine standard enterprise IPv6 allocation from an ISP.
An enterprise customer site typically receives a /48 prefix.
A /48 global routing prefix leaves bits 49 through 64 (16 bits) available for the enterprise organization to construct up to 65,536 distinct /64 subnets.
3
Evaluate point-to-point link prefix standards.
Point-to-point router links use a /127 prefix length.
Per RFC 6164, using a /127 mask limits available addresses on the link to two, preventing ping-pong routing loops and ND CPU exhaustion attacks.
4
Identify the Interface ID length in a standard IPv6 unicast address.
The Interface ID is exactly 64 bits.
IPv6 address architecture divides a standard 128-bit address into a 64-bit network prefix and a 64-bit host Interface ID.

Anahtar Kavram

IPv6 Address Structure and Prefix Allocation Rules
Soru 4Soru →

A network administrator is allocated the IPv6 prefix block 2001:db8:acad:4000::/522001:\text{db8}:\text{acad}:4000::/52 for a corporate branch network. The administrator needs to divide this block into standard /64/64 subnets for local LAN segments. How many /64/64 subnets can be created from this /52/52 prefix block?

Cevabı ve açıklamayı göster

Cevap: 4,096

Cevap

4,096 subnets can be created from a /52 prefix block when using a /64 prefix length.
To calculate the number of /64/64 subnets created from a /52/52 prefix, subtract the assigned prefix length from the target subnet length (64−52=1264 - 52 = 12 bits). Raising 2 to the power of the subnet bit count (2122^{12}) gives 4,096 unique /64/64 subnets.

Adım Adım Çözüm

1
Determine the number of bits available for subnetting
Subnet bits = 64−52=1264 - 52 = 12 bits
The difference between the target prefix length (/64) and the assigned prefix length (/52) defines the subnet ID space.
2
Calculate total subnets using powers of 2
212=4,0962^{12} = 4,096
Each additional binary bit doubles the number of available subnets.

Anahtar Kavram

IPv6 Prefix Subnetting
Soru 5Soru →

An administrator is configuring IPv6 addressing on a router interface and verifying reserved scope prefixes. Which two statements correctly describe IPv6 address representations and reserved prefix ranges? (Select two.)

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: The prefix fe80::/10 is reserved for IPv6 link-local addresses.; The IPv6 loopback address is represented as ::1/128.

Cevap

The prefix fe80::/10 is reserved for IPv6 link-local addresses, and the IPv6 loopback address is represented as ::1/128.
Link-local addresses strictly use the fe80::/10 prefix, and the loopback address for an IPv6 host interface is ::1/128.

Adım Adım Çözüm

1
Identify the reserved prefix ranges for link-local and unique local IPv6 address scopes.
The prefix fe80::/10 corresponds to link-local unicast addresses. The prefix fc00::/7 corresponds to Unique Local Addresses (ULA), not global unicast addresses (which use 2000::/3).
Understanding IPv6 scope prefixes is required to properly categorize address types.
2
Evaluate the rules of IPv6 address compression and special addresses.
The double colon (::) compression mechanism is allowed only once per address to maintain uncompressed length integrity. The IPv6 loopback address is designated as ::1/128.
RFC 4291 specifies rules for shortening IPv6 addresses and designates ::1/128 for node loopback testing.

Anahtar Kavram

IPv6 Address Scopes and Zero Compression Rules
Soru 6Soru →

Match each IPv6 address or prefix on the left with its corresponding functional characteristic or property on the right.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

2001:db8:abc:1200::/562001:\text{db8}:\text{abc}:1200::/56
fd00:db8:abc:1200::/64fd00:\text{db8}:\text{abc}:1200::/64
fe80::200:5eff:fe00:5301
ff02::1:ff00:5301

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

The correct pairings are: 2001:db8:abc:1200::/56 matches the global unicast prefix providing 256 subnets of /64 length; fd00:db8:abc:1200::/64 matches the unique local address prefix; fe80::200:5eff:fe00:5301 matches the link-local address created using EUI-64 from MAC 00:00:5e:00:53:01; and ff02::1:ff00:5301 matches the solicited-node multicast address.
Each IPv6 address and prefix matches its exact functional specification: 2001:db8:abc:1200::/56 yields 256 subnets of /64 size; fd00::/8 addresses are Unique Local Addresses; fe80::200:5eff:fe00:5301 correctly applies the 7th-bit flip and FFFE insertion to MAC 00:00:5e:00:53:01; and ff02::1:ff00:5301 uses the exact low 24 bits of the interface ID appended to the solicited-node multicast prefix.

Adım Adım Çözüm

1
Analyze the prefix length calculation for 2001:db8:abc:1200::/56
Difference between /64 and /56 is 8 bits (64−56=864 - 56 = 8). 28=2562^8 = 256 subnets.
Standard IPv6 subnets are designated at the /64 boundary.
2
Identify the IPv6 scope for fd00:db8:abc:1200::/64
Prefix starting with fd00::/8 is within fc00::/7.
fc00::/7 defines Unique Local Addresses (ULA), equivalent to IPv4 private addresses.
3
Perform Modified EUI-64 conversion on MAC 00:00:5e:00:53:01
First byte 0x00 binary (00000000) flipped 7th bit becomes 0x02 (00000010). Insert FFFE in center (0000:5E -> 0000:5EFF:FE00:5301). Prepend fe80:: prefix -> fe80::200:5eff:fe00:5301.
Modified EUI-64 flips the 7th bit (Universal/Local) and inserts FFFE between OUI and NIC specific bytes.
4
Derive the solicited-node multicast address for interface ID 0200:5eff:fe00:5301
Extract last 24 bits (00:5301) and append to prefix ff02::1:ff00:0/104 -> ff02::1:ff00:5301.
Solicited-node multicast addresses always start with ff02::1:ff00:0/104 and take the lowest 24 bits of the unicast address.

Anahtar Kavram

IPv6 Address Representation, Subnetting, Scopes, and EUI-64 / Solicited-Node Multicast Generation
Soru 7Soru →

An organization is assigned the IPv6 address block 2001:db8:1111:2000::/522001:\text{db8}:1111:2000::/52. A network engineer needs to configure a router interface within a new /64 subnet that has a 12-bit subnet ID extension of 0xA400x\text{A40} added to the base /52 prefix. The router interface uses EUI-64 to generate its interface identifier automatically based on its MAC address `0200.4C12.3456`. Which IPv6 Global Unicast Address will be dynamically configured on this interface?

Cevabı ve açıklamayı göster

Cevap: 2001:db8:1111:2a40::4cff:fe12:3456

Cevap

2001:db8:1111:2a40::4cff:fe12:3456
The subnet prefix is derived by adding the subnet ID extension 0xA400x\text{A40} to the base prefix 4th hextet (20002000), producing 2A402\text{A}40. For EUI-64 generation from MAC `0200.4C12.3456`, `FFFE` is inserted into the middle (`0200.4CFF.FE12.3456`), and the 7th bit of the first byte (`0x02` = `0000 0010`) is inverted to `0` (`0x00` = `0000 0000`), yielding `0000:4cff:fe12:3456`. Combining these results in `2001:db8:1111:2a40::4cff:fe12:3456`.

Adım Adım Çözüm

1
Calculate the /64 subnet prefix from the assigned /52 block and subnet offset
Subnet prefix is 2001:db8:1111:2a40::/64
The base /52 prefix ends at the 4th hex digit of the 4th hextet (20002000). Adding the 12-bit hex extension 0xA400x\text{A40} yields 2000+A40=2A402000 + \text{A40} = 2\text{A}40 in hexadecimal for the 4th hextet.
2
Split the MAC address 0200.4C12.3456 into two 24-bit halves and insert FFFE
Intermediate identifier is 0200:4CFF:FE12:3456
EUI-64 requires inserting the hex value FFFE into the middle of the 48-bit MAC address.
3
Invert the 7th bit (Universal/Local bit) of the first byte
First byte 0x02 (binary 0000 0010) becomes 0x00 (binary 0000 0000)
In EUI-64 generation, flipping the 7th bit changes a 1 to a 0 (or 0 to 1), transforming 0200:4CFF:FE12:3456 into 0000:4CFF:FE12:3456 (compressed as ::4cff:fe12:3456).
4
Combine the /64 prefix with the EUI-64 interface identifier
2001:db8:1111:2a40::4cff:fe12:3456
Merging 2001:db8:1111:2a40::/64 and 0000:4cff:fe12:3456 gives the final global unicast address.

Anahtar Kavram

IPv6 EUI-64 Interface Identifier Generation and Subnet Prefix Calculation
Soru 8Soru →

A network administrator is assigned the IPv6 prefix block `2001:db8:cafe:a000::/56` for a branch office. The administrator must divide this allocation into multiple `/64` subnets for individual client VLANs. Which prefix represents the last `/64` subnet available within this assigned block?

Cevabı ve açıklamayı göster

Cevap: 2001:db8:cafe:a0ff::/64

Cevap

The prefix 2001:db8:cafe:a0ff::/64 represents the last /64 subnet available within the assigned /56 block.
The prefix 2001:db8:cafe:a0ff::/64 correctly identifies the last /64 subnet within the 2001:db8:cafe:a000::/56 assignment. A /56 prefix allocates 8 bits (bits 57 through 64) for creating /64 subnets, which correspond to the last two hexadecimal digits of the fourth hextet. The range of the fourth hextet for these subnets is from a000 to a0ff.

Adım Adım Çözüm

1
Determine the number of subnet bits available between the assigned prefix length (/56) and the target prefix length (/64).
64 - 56 = 8 subnet bits, which equal 2 hexadecimal digits.
Each hexadecimal character in an IPv6 address represents 4 bits (1 nibble).
2
Identify which hextet and bit positions contain these subnet bits.
The first 48 bits cover the first three hextets (2001:db8:cafe:). The assigned /56 prefix includes the first 8 bits of the fourth hextet ('a0'). The subnet bits occupy the remaining 8 bits of the fourth hextet.
The fourth hextet spans bits 49 through 64.
3
Calculate the maximum value for the 8 subnet bits.
8 bits of all binary 1s equal hex 'ff'. The fourth hextet ranges from 'a000' (first subnet) to 'a0ff' (last subnet).
Hexadecimal 'a0' followed by 'ff' forms the last valid /64 prefix.

Anahtar Kavram

IPv6 Subnetting and Prefix Length Calculations
Soru 9Soru →

An organization is assigned the IPv6 global routing prefix 2001:db8:abc0::/482001:\text{db8}:\text{abc0}::/48. A network engineer needs to configure the 16th subnet (subnet index 15 in hexadecimal count starting from 0) using standard /64/64 subnets. The router interface on this subnet is configured to dynamically derive its 64-bit interface identifier using EUI-64 based on its MAC address of 70-69-79-A1-B2-C3\text{70-69-79-A1-B2-C3}. Which fully formed and compressed IPv6 global unicast address will be assigned to this interface?

Cevabı ve açıklamayı göster

Cevap: 2001:db8:abc0:f:7269:79ff:fea1:b2c3

Cevap

The correct IPv6 address is 2001:db8:abc0:f:7269:79ff:fea1:b2c3.
The correct answer properly converts the 16th subnet index (15) to hexadecimal 'f', inserts the 'FFFE' pattern into the MAC address, and flips the 7th bit of the first byte (from 0x70 to 0x72) to form the valid EUI-64 interface identifier.

Adım Adım Çözüm

1
Determine the Subnet ID
The subnet ID is 0x000F (compressed to 'f').
Starting from subnet index 0 (2001:db8:abc0:0::/642001:\text{db8}:\text{abc0}:0::/64), the 16th subnet corresponds to index 15, which in hexadecimal is 0x000F.
2
Insert FFFE into the MAC address
7069:79FF:FEA1:B2C3
EUI-64 construction requires splitting the 48-bit MAC address (70-69-79-A1-B2-C3) into two 24-bit halves and inserting 0xFFFE between them.
3
Invert the Universal/Local (7th) bit of the first byte
First byte changes from 0x70 to 0x72.
The first byte 0x70 in binary is 0111 0000. Inverting the 7th bit (bit position 7 from MSB) yields 0111 0010, which is 0x72 in hexadecimal. Thus, the interface ID becomes 7269:79ff:fea1:b2c3.
4
Combine the network prefix, subnet ID, and interface ID
2001:db8:abc0:f:7269:79ff:fea1:b2c3
Combining 2001:db8:abc0::2001:\text{db8}:\text{abc0}:: + f::f:: + 7269:79ff:fea1:b2c37269:79\text{ff}:\text{fea1}:b2c3 produces the complete IPv6 address.

Anahtar Kavram

EUI-64 Interface Identifier Construction and Hexadecimal IPv6 Subnetting
Soru 10Soru →

Match each IPv6 address prefix on the left to its designated address scope or function on the right.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

2000::/3
fe80::/10
fc00::/7
ff00::/8

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

2000::/3 matches Global Unicast, fe80::/10 matches Link-Local, fc00::/7 matches Unique Local, and ff00::/8 matches Multicast.
Each prefix correctly maps to its standard RFC-defined IPv6 address scope: 2000::/3 is Global Unicast, fe80::/10 is Link-Local, fc00::/7 is Unique Local, and ff00::/8 is Multicast.

Adım Adım Çözüm

1
Identify the Global Unicast range
2000::/3 covers 2000:: through 3fff:ffff:ffff:ffff:ffff:ffff:ffff:ffff, which represents Global Unicast.
Standard IANA IPv6 allocation reserves 2000::/3 for public Internet routing.
2
Identify the Link-Local prefix
fe80::/10 covers fe80:: through febf::, which is reserved for Link-Local addresses.
Link-Local addresses are automatically configured on enabled IPv6 interfaces for local link communication.
3
Identify the Unique Local prefix
fc00::/7 covers fc00:: through fdff::, designated as Unique Local.
Unique Local addresses provide private addressing space within internal networks and are not routed on the global Internet.
4
Identify the Multicast prefix
ff00::/8 covers all multicast traffic.
IPv6 uses multicast exclusively instead of broadcast; all multicast addresses begin with ff00::/8.

Anahtar Kavram

IPv6 Address Scopes and Prefixes
Soru 11Soru →

A network administrator is configuring IPv6 auto-configuration using SLAAC and EUI-64 process on Cisco router interfaces. Match each 48-bit MAC address on the left to its corresponding EUI-64 derived IPv6 Link-Local address on the right.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

0012.3456.789A
0212.3456.789A
1012.3456.789A
1212.3456.789A

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

MAC 0012.3456.789A matches fe80::212:34ff:fe56:789a; MAC 0212.3456.789A matches fe80::12:34ff:fe56:789a; MAC 1012.3456.789A matches fe80::1212:34ff:fe56:789a; MAC 1212.3456.789A matches fe80::1012:34ff:fe56:789a.
Each MAC address is correctly converted to EUI-64 format by inserting FFFE into the middle of the 48-bit address and inverting the 7th bit (the Universal/Local bit) of the first byte. The resulting 64-bit interface ID is appended to the Link-Local prefix fe80::/64, with leading zeros in any 16-bit block omitted per standard IPv6 address formatting rules.

Adım Adım Çözüm

1
Split each MAC address into its OUI (first 24 bits) and NIC-specific extension (last 24 bits), and insert FFFE in hex between them.
For MAC 0012.3456.789A, the split sequence becomes 00-12-34-FF-FE-56-78-9A.
EUI-64 expansion requires inserting the 16-bit reserved value FFFE into the center of a 48-bit MAC address.
2
Invert the 7th bit (Universal/Local bit) of the first byte in binary representation.
Byte 0x00 (00000000200000000_2) becomes 0x02 (00000010200000010_2); 0x02 becomes 0x00; 0x10 (00010000200010000_2) becomes 0x12 (00010010200010010_2); 0x12 becomes 0x10.
IEEE EUI-64 specification requires flipping the 7th bit of the first octet to represent global/local scope.
3
Combine the inverted 64-bit interface ID with the fe80::/10 link-local prefix (defaulting to /64 subnet prefix fe80::/64) and apply standard RFC 4291 zero compression rules.
The 64-bit interface ID 0012:34ff:fe56:789a compresses leading zeros to 12:34ff:fe56:789a, resulting in fe80::12:34ff:fe56:789a.
Standard IPv6 address formatting suppresses leading zeros in each 16-bit hex field.

Anahtar Kavram

EUI-64 Interface Identifier Generation and SLAAC Link-Local Addressing
Soru 12Soru →

An engineer enters the following configuration command on a Cisco router interface whose hardware MAC address is `0A00.2712.3456`:

`R1(config-if)# ipv6 address 2001:db8:acad:b000::/64 eui-64`

Which fully compressed IPv6 global unicast address will be dynamically assigned to this interface?

Cevabı ve açıklamayı göster

Cevap: 2001:db8:acad:b000:800:27ff:fe12:3456

Cevap

The correct dynamically generated address is 2001:db8:acad:b000:800:27ff:fe12:3456.
To derive the EUI-64 interface identifier from MAC address 0A00.2712.3456, insert FFFE between the 24-bit OUI and 24-bit NIC identifier to get 0A00:27FF:FE12:3456. Invert the 7th bit of the first hex byte (0A = 0000 1010 -> 08 = 0000 1000), resulting in 0800:27FF:FE12:3456. Combining this with prefix 2001:db8:acad:b000::/64 and suppressing the leading zero in 0800 yields 2001:db8:acad:b000:800:27ff:fe12:3456.

Adım Adım Çözüm

1
Split MAC address and insert FFFE into the middle
MAC 0A00.2712.3456 becomes 0A00:27FF:FE12:3456.
EUI-64 generation requires expanding a 48-bit MAC address into a 64-bit interface ID by inserting FFFE (0xFFFE) between the OUI and device identifier.
2
Invert the 7th bit (Universal/Local bit) of the first byte
First byte 0A (binary 0000 1010) becomes 08 (binary 0000 1000).
The IEEE standard specifies that the 7th bit of the first byte must be inverted to indicate a globally unique, locally configured IPv6 interface identifier.
3
Combine the subnet prefix and interface ID, applying IPv6 compression rules
2001:db8:acad:b000:0800:27ff:fe12:3456 compresses to 2001:db8:acad:b000:800:27ff:fe12:3456.
Leading zeros within a hextet must be suppressed (0800 becomes 800), while non-zero fields like b000 retain their representation.

Anahtar Kavram

EUI-64 Interface Identifier Generation
Tahmini Süre:2m 0s
Soru 13Soru →

An administrator enables IPv6 on a router interface using the prefix 2001:db8:feed:1::/642001:\text{db8}:\text{feed}:1::/64 with EUI-64 automatic interface identifier generation. If the interface MAC address is `1C1D.86AB.CDEF`, which IPv6 address is dynamically assigned to the interface?

Cevabı ve açıklamayı göster

Cevap: 2001:db8:feed:1:1e1d:86ff:feab:cdef

Cevap

2001:db8:feed:1:1e1d:86ff:feab:cdef
Generating an IPv6 EUI-64 interface identifier from a 48-bit MAC address requires splitting the MAC address into two 24-bit halves, inserting the hexadecimal sequence FFFE in the center, and flipping the 7th bit (Universal/Local bit) of the first byte. For MAC address 1C1D.86AB.CDEF, the first byte 0x1C (binary 00011100) becomes 0x1E (binary 00011110) after flipping the 7th bit. Inserting FFFE into the center yields the 64-bit interface ID 1e1d:86ff:feab:cdef, which combines with prefix 2001:db8:feed:1::/64 to form 2001:db8:feed:1:1e1d:86ff:feab:cdef.

Adım Adım Çözüm

1
Split MAC address into two 24-bit halves
First half: 1C-1D-86, Second half: AB-CD-EF
EUI-64 insertion requires placing a 16-bit payload into the middle of the 48-bit MAC address.
2
Insert the 16-bit value FFFE into the center
1C-1D-86-FF-FE-AB-CD-EF
Standard EUI-64 processing expands 48-bit MAC addresses to 64-bit interface identifiers.
3
Invert the 7th bit (Universal/Local bit) of the first octet
0x1C (0001 1100) becomes 0x1E (0001 1110), yielding 1E-1D-86-FF-FE-AB-CD-EF
RFC 4291 requires flipping the 7th bit of the IEEE MAC address when converting to EUI-64 format.
4
Combine with IPv6 prefix
2001:db8:feed:1:1e1d:86ff:feab:cdef
Appending the 64-bit interface identifier to the /64 prefix constructs the complete IPv6 address.

Anahtar Kavram

EUI-64 Interface Identifier Generation
Soru 14Soru →

A network engineer is configuring an interface on a Cisco router for VLAN 270 using the assigned IPv6 block 2001:db8:abcd::/482001:\text{db8}:\text{abcd}::/48. Per organization policy, the 16-bit subnet ID field in the /64/64 prefix must be the exact hexadecimal equivalent of the decimal VLAN ID (27010270_{10}). The router interface has a hardware MAC address of `3C4A.9211.2233` and is configured with the command `ipv6 address 2001:db8:abcd:10e::/64 eui-64`. Which IPv6 global unicast address will be dynamically generated on this interface?

Cevabı ve açıklamayı göster

Cevap: 2001:db8:abcd:10e:3e4a:92ff:fe11:2233

Cevap

2001:db8:abcd:10e:3e4a:92ff:fe11:2233
The correct option correctly converts decimal VLAN 270 into hexadecimal 010E (`10e`), inserts `FFFE` into the MAC address `3C4A.9211.2233`, and flips the 7th bit of the first byte (`3C` = `0011 1100` -> `0011 1110` = `3E`), producing the full IPv6 address `2001:db8:abcd:10e:3e4a:92ff:fe11:2233`.

Adım Adım Çözüm

1
Calculate the 16-bit Subnet ID from the decimal VLAN ID
Decimal 27010=(1×162)+(0×161)+(14×160)=0x010E270_{10} = (1 \times 16^2) + (0 \times 16^1) + (14 \times 16^0) = 0x010E, which compresses to `10e` in the 4th hextet.
IPv6 hextets are written in hexadecimal format. Converting decimal 270 yields 010E.
2
Insert FFFE into the middle of the 48-bit MAC address
MAC `3C4A.9211.2233` becomes `3C4A:92FF:FE11:2233`.
EUI-64 generation splits the 6-byte MAC address into two 3-byte halves and inserts `FF-FE` (16 bits) in between.
3
Invert the 7th bit (Universal/Local bit) of the first MAC octet
First octet `3C` in binary is `0011 1100`. Inverting the 7th bit (bit 1 from the right in the first byte) changes it to `0011 1110`, which equals `3E` in hexadecimal.
IEEE EUI-64 standard dictates that the 7th bit of the interface ID must be inverted (0 for global scope, 1 for local scope).
4
Combine the /64 prefix with the EUI-64 interface identifier
`2001:db8:abcd:10e:3e4a:92ff:fe11:2233`.
Appending the 64-bit interface ID `3e4a:92ff:fe11:2233` to the /64 prefix `2001:db8:abcd:10e::/64` yields the final global unicast IPv6 address.

Anahtar Kavram

EUI-64 Interface Identifier Generation & IPv6 Hexadecimal Subnetting
Soru 15Soru →

A network administrator configures a Cisco router interface using the command `ipv6 address 2001:db8:4444:5555::/64 eui-64`. If the MAC address of the interface is 0800.2765.43210800.2765.4321, which full IPv6 global unicast address is generated for this interface?

Cevabı ve açıklamayı göster

Cevap: 2001:db8:4444:5555:a00:27ff:fe65:4321

Cevap

2001:db8:4444:5555:a00:27ff:fe65:4321
The correct IPv6 address is constructed by taking the MAC address 0800.2765.4321, inserting FFFE between the third and fourth bytes to form 0800:27FF:FE65:4321, and flipping the 7th bit of the first byte (changing 08 to 0A). Compressing the leading zero of 0A00 produces a00:27ff:fe65:4321, which appends to the prefix 2001:db8:4444:5555::/64.

Adım Adım Çözüm

1
Split the 48-bit MAC address into two 24-bit halves and insert FFFE in the middle.
MAC address 0800.2765.4321 becomes 0800:27FF:FE65:4321.
EUI-64 generation requires expanding a 48-bit MAC address into a 64-bit interface ID by inserting FFFE into the center.
2
Invert the 7th bit (universal/local bit) of the first octet.
First octet 08 in hex is 0000 1000 in binary. Flipping the 7th bit yields 0000 1010 in binary, which is 0A in hex. The identifier becomes 0A00:27FF:FE65:4321.
IEEE EUI-64 rules mandate flipping the 7th bit of the MAC address to indicate universal scope.
3
Combine the /64 IPv6 prefix with the EUI-64 interface ID and apply RFC 4291/5952 zero compression rules.
Prefix 2001:db8:4444:5555::/64 + Interface ID 0a00:27ff:fe65:4321 = 2001:db8:4444:5555:a00:27ff:fe65:4321.
Leading zeros in any 16-bit hexadecimal field are omitted (0a00 becomes a00).

Anahtar Kavram

EUI-64 Interface Identifier Generation
Tahmini Süre:1m 30s
Soru 16Soru →

A network administrator is evaluating IPv6 addressing structures for a router interface configuration. Which two statements correctly describe IPv6 prefix properties or address compression rules?

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: The address 2001:db8:0000:0000:0000:0000:0000:00012001:\text{db8}:0000:0000:0000:0000:0000:0001 can be validly compressed to 2001:db8::12001:\text{db8}::1.; The prefix fe80::/10\text{fe80}::/10 is designated for link-local addresses, which are automatically generated and non-routable beyond the local link.

Cevap

The correct statements are that 2001:db8:0000:0000:0000:0000:0000:0001 can be compressed to 2001:db8::1, and that fe80::/10 is designated for link-local non-routable addresses.
Compressing consecutive zero fields into a single double colon once per address is valid according to RFC 4291 rules. Furthermore, fe80::/10 is officially designated for link-local communication and is restricted to the local layer 2 segment.

Adım Adım Çözüm

1
Analyze IPv6 zero compression rules according to RFC 4291.
Consecutive blocks of zeros can be replaced by double colons (::), but only ONCE per address representation to prevent ambiguity.
Compressing 2001:db8:0000:0000:0000:0000:0000:0001 into 2001:db8::1 uses the double colon once legally, while 2001:db8::100::1 violates this rule.
2
Evaluate reserved IPv6 prefix scopes.
The fe80::/10 block is reserved for link-local unicast addresses.
Link-local addresses are required on all IPv6-enabled interfaces, automatically configured, and never forwarded by routers outside the local link boundary.
3
Evaluate subnet capacity logic in IPv6 vs IPv4.
IPv6 eliminates broadcast addressing in favor of multicast, so subtracting 2 addresses for network and broadcast is unnecessary in IPv6 subnets.
All 2642^{64} host combinations in a standard /64 subnet interface ID space are available as unique host identifiers.

Anahtar Kavram

IPv6 Address Representation and Scopes
Soru 17Soru →

Match each IPv6 prefix or address block on the left with its correct architectural scope and function on the right.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

2000::/3
fe80::/10
fc00::/7
ff02::2

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

2000::/3 matches Global Unicast Address range reserved for publicly routable Internet communication; fe80::/10 matches Link-Local unicast prefix mandatory for single-segment neighbor communication; fc00::/7 matches Unique Local Address prefix used for private internal site routing; ff02::2 matches All-routers link-local multicast address targeting all routers on the segment.
Each IPv6 address prefix maps precisely to its RFC-defined scope: 2000::/3 is Global Unicast, fe80::/10 is Link-Local, fc00::/7 is Unique Local, and ff02::2 is the all-routers multicast group address.

Adım Adım Çözüm

1
Identify the primary block for Global Unicast Addresses (GUA)
2000::/3 encompasses all addresses from 2000:: through 3fff:ffff:ffff:ffff:ffff:ffff:ffff:ffff, which are globally routable.
IANA allocates GUA prefix blocks starting within the 2000::/3 range.
2
Identify the designated Link-Local unicast prefix scope
fe80::/10 defines the range fe80:: through febf:ffff:ffff:ffff:ffff:ffff:ffff:ffff used for intra-link communication.
IPv6 devices use link-local addresses for neighbor discovery and router solicitations.
3
Identify the private/internal IPv6 address range
fc00::/7 covers the block fc00:: through fdff:ffff:ffff:ffff:ffff:ffff:ffff:ffff for Unique Local Addresses.
ULAs provide non-globally routable addressing within private organizational boundaries.
4
Identify specific well-known IPv6 multicast group addresses
ff02::2 is the link-local scope multicast address received by all active routers on a network segment.
Multicast prefix ff00::/8 uses the scope indicator 2 (link-local) and group ID 2 (all routers).

Anahtar Kavram

IPv6 Address Scopes and Reserved Prefixes
Soru 18Soru →

Match each fully expanded IPv6 address on the left with its standard canonical compressed representation on the right according to RFC 5952 rules.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

2001:0db8:0000:0000:0042:0000:0000:0001
2001:0db8:0000:00ab:0000:0000:0000:0001
fe80:0000:0000:0000:0000:0000:0000:0001
2001:0db8:0000:0000:0000:00b0:0000:0000

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

The correct pairings match each expanded IPv6 address to its RFC 5952 canonical compressed form: 2001:0db8:0000:0000:0042:0000:0000:0001 pairs with 2001:db8::42:0:0:1; 2001:0db8:0000:00ab:0000:0000:0000:0001 pairs with 2001:db8:0:ab::1; fe80:0000:0000:0000:0000:0000:0000:0001 pairs with fe80::1; and 2001:0db8:0000:0000:0000:00b0:0000:0000 pairs with 2001:db8::b0:0:0.
The correct pairings strictly adhere to RFC 5952 canonical formatting rules: leading zeros within any 16-bit field are omitted, the single longest contiguous sequence of zero-value 16-bit fields is replaced with ::, and when sequences of zero fields are equal in length, the first sequence is compressed.

Adım Adım Çözüm

1
Remove leading zeros from each 16-bit hexadecimal field (hextet).
Fields such as '0db8' become 'db8', '0042' becomes '42', '0000' becomes '0', and '0001' becomes '1'.
RFC 5952 requires leading zeros to be suppressed in every hextet.
2
Identify contiguous zero hextets and apply the double colon (::) compression rule.
For 2001:0db8:0000:0000:0042:0000:0000:0001, there are two equal runs of 2 zero hextets. Compress the first run to yield 2001:db8::42:0:0:1.
When zero sequences are of equal length, RFC 5952 requires compressing the first sequence.
3
Evaluate remaining addresses for longest zero sequence compression.
Compress the sequence of 3 zero hextets in 2001:0db8:0000:00ab:0000:0000:0000:0001 to get 2001:db8:0:ab::1, and the 6 zero hextets in fe80:0000:0000:0000:0000:0000:0000:0001 to get fe80::1.
The double colon must represent the maximum possible consecutive zero hextets when lengths differ.

Anahtar Kavram

IPv6 Address Compression and Canonical Representation (RFC 5952)
Soru 19Soru →

When an interface automatically constructs an IPv6 EUI-64 interface identifier using the MAC address 00:1A:2B:3C:4D:5E, which string represents the correctly generated 64-bit interface ID?

Cevabı ve açıklamayı göster

Cevap: 021a:2bff:fe3c:4d5e

Cevap

The correct interface identifier is 021a:2bff:fe3c:4d5e.
To create a 64-bit EUI-64 interface ID from a 48-bit MAC address, the 16-bit value FFFE is inserted between the third and fourth bytes of the MAC address. In addition, the 7th bit (universal/local bit) of the first byte must be inverted. Inverting the 7th bit of 0x00 results in 0x02, producing the complete interface ID 021a:2bff:fe3c:4d5e.

Adım Adım Çözüm

1
Split the 48-bit MAC address into two 24-bit halves.
The left half is 00:1A:2B and the right half is 3C:4D:5E.
EUI-64 generation requires inserting a specific 16-bit hex value between the OUI and NIC specific bytes.
2
Insert the 16-bit hexadecimal value FFFE between the two halves.
The combined value becomes 00:1A:2B:FF:FE:3C:4D:5E.
FFFE expands the 48-bit MAC address into a 64-bit structure.
3
Invert the 7th bit (Universal/Local bit) of the first byte (00).
Hexadecimal 00 (0000 0000 in binary) becomes hexadecimal 02 (0000 0010 in binary).
IEEE EUI-64 rules require modifying the 7th bit to represent universal scope.
4
Format the resulting 64 bits into standard IPv6 colon-separated hextets.
021a:2bff:fe3c:4d5e
IPv6 interface identifiers are presented as four 16-bit hexadecimal hextets.

Anahtar Kavram

EUI-64 Interface ID Generation
Tahmini Süre:45s
Soru 20Soru →

A network engineer is configuring a Cisco router interface with a MAC address of `0050.568A.B1C2`. The interface is enabled for IPv6 using SLAAC with EUI-64 interface identifier generation under the prefix `2001:db8:1:1::/64`. Additionally, the engineer plans to configure a Unique Local Address (ULA) on the same interface. Which TWO statements regarding the IPv6 addressing for this interface are correct? (Select TWO.)

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: The dynamically generated link-local IPv6 address on the interface is `fe80::250:56ff:fe8a:b1c2`.; Any valid Unique Local Address configured on this interface must fall within the prefix range `fc00::/7`.

Cevap

The correct statements are that the dynamically generated link-local IPv6 address is `fe80::250:56ff:fe8a:b1c2` and that any Unique Local Address must fall within the `fc00::/7` prefix block.
Generating an EUI-64 address from MAC `0050.568A.B1C2` involves inserting `FFFE` into the middle (`0050:56FF:FE8A:B1C2`) and toggling the 7th bit from 0 to 1 (`00` hex becomes `02` hex), producing interface ID `0250:56ff:fe8a:b1c2`. Prepended with `fe80::`, this forms the valid link-local address `fe80::250:56ff:fe8a:b1c2`. Furthermore, RFC 4193 specifies `fc00::/7` as the designated address range for IPv6 Unique Local Addresses.

Adım Adım Çözüm

1
Calculate the EUI-64 interface identifier from MAC address `0050.568A.B1C2`.
Insert `FFFE` in the middle of the 48-bit MAC address: `0050:56FF:FE8A:B1C2`. Invert the 7th bit (Universal/Local bit) of the first byte: `00` (`0000 0000`) becomes `02` (`0000 0010`). The resulting EUI-64 interface ID is `0250:56ff:fe8a:b1c2`.
IEEE EUI-64 conversion rules mandate inserting `FFFE` between the OUI and NIC specific identifier and setting the 7th bit to 1 for globally unique MAC addresses.
2
Form the link-local address using the EUI-64 interface ID.
Combine `fe80::/10` with interface ID `0250:56ff:fe8a:b1c2` to get `fe80::250:56ff:fe8a:b1c2`.
Link-local addresses start with the `fe80::/10` prefix followed by 54 zero bits and the 64-bit interface identifier.
3
Identify the reserved prefix scope for IPv6 Unique Local Addresses (ULA).
ULAs are defined under `fc00::/7`.
RFC 4193 designates `fc00::/7` for Unique Local Unicast addresses, serving a role similar to RFC 1918 private IPv4 addresses.

Anahtar Kavram

EUI-64 Interface Identifier Generation & IPv6 Address Scopes
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